Setting device, setting method, and computer-readable recording medium

Abstract

The present invention relates to a setting device, a setting method, and a computer-readable recording medium for realizing low power of a loop. The setting device (10) is provided with: a communication unit that performs communication for acquiring a second current output range of a transmission signal via a loop formed between an inverter that converts a physical quantity into a current value and an input / output device that outputs the current value input from the inverter to a system; the minimum current value or the maximum current value is smaller than that of the first current output range; and a setting unit that sets a current output corresponding to either the first current output range or the second current output range on the basis of whether or not the acquisition of the second current output range is successful.

Description

Technical Field

[0001] The present invention relates to a setting device, a setting method, and a computer-readable recording medium. Background Art

[0002] In a case where physical quantities such as differential pressure, temperature, and flow rate are measured in a workshop or the like, a two-wire transducer is used. The two-wire transducer converts measured values such as flow rate and differential pressure into a current output range of an instrument unified signal, that is, a current value of 4 - 20 mA, and transmits it to an input / output device as a power supply source via a loop formed by two wires that share the same cable for power supply line and signal line. The input / output device supplies a DC voltage of 24 V to the two-wire transducer, and converts the current value of 4 - 20 mA transmitted from the two-wire transducer into a signal requested by the system.

[0003] Patent Document 1: Japanese Patent Laid-Open No. 2013-92971 Summary of the Invention

[0004] However, the above-mentioned 4 - 20 mA has become a world standard as a transmission signal for instruments defined by the IEC (International Electrotechnical Commission), and thus has not been studied as an inviolable field. Therefore, there is an aspect in which it is difficult to achieve low power consumption of the above loop.

[0005] An object of the present invention is to achieve low power consumption of the loop.

[0006] A setting device according to an aspect of the present invention includes: a communication unit that performs communication to acquire a second current output range, the second current output range being a current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to a system, and having a minimum current value or a maximum current value smaller than a first current output range; and a setting unit that sets a current output corresponding to either the first current output range or the second current output range based on whether acquisition of the second current output range is successful.

[0007] Regarding a setting method according to an aspect of the present invention, a processor executes the following processing: performing communication to acquire a second current output range, the second current output range being a current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to a system, and having a minimum current value or a maximum current value smaller than a first current output range, and setting a current output corresponding to either the first current output range or the second current output range based on whether acquisition of the second current output range is successful.

[0008] One aspect of the present invention relates to a computer-readable recording medium storing a setting program that causes a computer to perform the following processes: performing communication to obtain a second current output range, which is a current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to a system, and is smaller in minimum current value or maximum current value than a first current output range, and setting a current output corresponding to either the first current output range or the second current output range based on whether the acquisition of the second current output range is successful.

[0009] Effect of the Invention

[0010] According to one embodiment, low power consumption of the loop can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a block diagram showing a functional configuration example of a setting device.

[0012] Figure 2 It is a schematic diagram showing an operation example of the entire loop.

[0013] Figure 3 It is a diagram showing an example of HART communication.

[0014] Figure 4 It is a schematic diagram showing an example of path resistance.

[0015] Figure 5 It is a diagram showing an example of current setting in a low current mode.

[0016] Figure 6 It is a diagram showing the power reduction effect of different modes.

[0017] Figure 7 It is a schematic diagram showing an operation example of Mode 8.

[0018] Figure 8 It is a schematic diagram showing an operation example of Mode 1.

[0019] Figure 9 It is a flowchart (1) showing the flow of a setting process.

[0020] Figure 10 It is a flowchart (2) showing the flow of a setting process.

[0021] Figure 11 It is a block diagram showing a functional configuration example of an input / output device and a transducer.

[0022] Figure 12It is a sequence diagram showing the operations of the input / output device and the two-wire converter.

[0023] Figure 13 It is a diagram showing an example of the application ranges of the low-current mode and the low-voltage mode.

[0024] Figure 14 It is a diagram showing an example of the hardware structure. Detailed implementation manners

[0025] Hereinafter, a manner (hereinafter referred to as "implementation manner") for implementing the setting device, the setting method, and the setting program related to the present application will be described with reference to the accompanying drawings. Examples are shown in each implementation manner, and the structure, configuration, function, numerical values used for the above determination, usage scenarios, etc. are not limited by such examples. Moreover, each implementation manner can be appropriately combined within the range where the processing contents do not conflict.

[0026] <Overall structure>

[0027] Figure 1 It is a block diagram showing an example of the functional structure of the setting device. Figure 1 The shown setting device 10 provides a setting function, which is to set the current output of the instrument transmission signal transmitted and received via a loop formed between a converter that converts a physical quantity measured in a workshop or the like into a current value and an input / output device that outputs the current value input from the converter to the system.

[0028] As one aspect, the setting device 10 can be implemented as a converter or an input / output device. For example, the converter can be a field instrument installed in a workshop, such as an instrument for measuring physical quantities such as differential pressure, temperature, and flow rate. In addition, the input / output device can be a DCS (Distributed Control Systems) or a PLC (Programmable Logic Controller). Furthermore, the setting device 10 can be implemented as a control device connected to the converter or the input / output device in a communicable manner.

[0029] <4 - 20mA>

[0030] An operation example of the entire loop using the 4 - 20mA signal will be described. Figure 2 It is a schematic diagram showing an operation example of the entire loop. As Figure 2 shown, between the input / output device 30 and the two-wire converter 50, a loop 3 is formed by two wires in which the power line and the signal line share the same cable.

[0031] Next, in the present embodiment, as an example of the converter, a two-wire converter is cited, but the connection method of the converter is not limited to the two-wire type. In addition, it is declared in advance that in the following text, Figure 13 it will be described in detail, but the connection method of the converter can also be a three-wire type or a four-wire type.

[0032] As one aspect, Loop 3 functions as a power supply line. For example, in Loop 3, a DC voltage of 24V is supplied from the input / output device 30 to the two-wire converter 50, and the two-wire converter 50 operates with the DC voltage of 24V.

[0033] As another aspect, Loop 3 also functions as a signal output line. For example, the two-wire converter 50 converts the measured value obtained by measuring physical quantities such as flow rate and differential pressure into a current value within the current output range of the instrument unified signal, i.e., 4 - 20mA, and transmits this current value to the input / output device 30 via Loop 3.

[0034] The current value thus transmitted to the input / output device 30 is output to the system 70 on the basis of being converted into the signal requested by the system 70. And the system 70 converts the voltage value output by the input / output device 30 into a process value (%).

[0035] For example, the system 70 can be implemented as a plant information management system (PIMS) that manages the time-series data of the process value as historical data.

[0036] The current output range used in such Loop 3, i.e., 4 - 20mA, has become a world standard as a transmission signal for instruments. When automatic control began to be used in the process, the signal current value transmitted differed depending on the manufacturer. In the case where the manufacturers of the input / output device 30 and the two-wire converter 50 are different, it is difficult to ensure interchangeability for signal transmission and reception. However, regarding IEC381 (subsequently IEC60381-1), by unifying it to a current value of 4 - 20mA, the connection between the input / output device 30 and the two-wire converter 50 has become easier, greatly contributing to the development of automatic control.

[0037] As the first point where the 4 - 20mA signal is excellent, it can be cited that it is a current signal. Since it is not a voltage signal, the signal amplitude does not decay in proportion to the length of the cable. As the second point, it can be cited that it is a DC signal. Since it is not an AC signal, it can be cited that noise can be easily removed using a low-pass filter and it is strong against noise.

[0038] <One aspect of the problem>

[0039] With significant changes in the social environment, the contribution of enterprises to the SDGs (Sustainable Development Goals) is important.

[0040] Each manufacturer aims to further achieve low power consumption in product development, but has not started researching the low power consumption of the power determined by the instrument unified signal (4 - 20mA signal) and its power supply voltage (24V). As one of the reasons, the instrument unified signal and its power supply voltage are world standards, so not everyone in the art wants to make changes.

[0041] For example, Figure 2 in the example shown, the entire loop 3 consumes power [W] of 24V×(4 - 20mA), so the power consumption increases in direct proportion to 24V and 4 - 20mA.

[0042] <One aspect of the solution to the problem>

[0043] Therefore, in this embodiment, for the instruments of both the input / output device 30 and the two-wire converter 50, a low current mode that operates in a current output range smaller than the minimum current value or the maximum current value compared to the 4 - 20mA current output range corresponding to the instrument unified signal is introduced.

[0044] Hereinafter, the current output range corresponding to the 4 - 20mA of the instrument unified signal may be denoted as the "first current output range", and the mode that operates in the first current output range may be denoted as the "standard mode". And the current output range corresponding to the low current mode may be denoted as the "second current output range".

[0045] In the case of introducing the low current mode in this way, an environment where the standard mode and the low current mode coexist is constructed for the instruments of both the input / output device 30 and the two-wire converter 50. In this case, an environment is created where it is not necessary for the instruments of both the input / output device 30 and the two-wire converter 50 to enable the low current mode to operate.

[0046] This is because the timing of introducing the input / output device 30 and the two-wire converter 50 into the workshop etc. may be different, and even if the introduction timing is the same, the manufacturers of the input / output device 30 and the two-wire converter 50 may be different.

[0047] In this environment, different modes are set between the input / output device 30 and the dual-line converter 50, or even if any of the input / output device 30 and the dual-line converter 50 cannot operate in the low-current mode, the low-current mode is still set. In this case, the operations of the input / output device 30 and the dual-line converter 50 result in malfunctions, so the input / output device 30 and the dual-line converter 50 cannot operate normally.

[0048] Therefore, in the present embodiment, the following setting function is achieved, that is, according to whether the acquisition of the second current output range from the input / output device 30 and the dual-line converter 50 is successful, the current output corresponding to either the standard mode or the low-current mode is set.

[0049] For example, when the acquisition of the second current output range is successful, the current output corresponding to the low-current mode can be set. On the other hand, when the acquisition of the second current output range fails, the current output corresponding to the standard mode can be set.

[0050] Therefore, when the low-current mode is introduced, the input / output device 30 and the dual-line converter 50 can both operate normally.

[0051] Therefore, according to the setting function of the present embodiment, the low power consumption of the loop can be achieved.

[0052] <Structure of the setting device 10>

[0053] Next, a functional structure example of the setting device 10 having the above setting function will be described. In Figure 1 a module related to the setting function of the setting device 10 is schematically shown. As Figure 1 shown, the setting device 10 has a communication unit 11, a voltage adjustment unit 13, a setting unit 15, and an operation control unit 17. In addition, Figure 1 only the functional units related to the above setting function are selectively shown, but the setting device 10 can also have functional units other than those shown in the figure.

[0054] The communication unit 11 is a processing unit that performs digital communication between the input / output device 30 and the dual-line converter 50. Regarding this digital communication, as an example, it can be achieved by a hybrid communication method in which a digital signal is superimposed on an analog signal transmitted via the loop 3, such as HART (Highway Addressable Remote Transducer).

[0055] Figure 3 is a diagram showing an example of HART communication. In Figure 3An example of transmitting and receiving an analog signal in the first current output range, i.e., 4 - 20 mA, via loop 3 between input / output device 30 and dual-line converter 50 is shown. As Figure 3 shown, a frequency signal representing "0" or "1" is superimposed on the 4 - 20 mA analog signal. Thereby, two-way digital communication can be achieved between input / output device 30 and dual-line converter 50.

[0056] In addition to input / output device 30 being able to set the state, parameters, etc. of dual-line converter 50 via such digital communication, dual-line converter 50 can also transmit the measured value of the physical quantity to input / output device 30.

[0057] Voltage adjustment unit 13 is a processing unit that adjusts the DC voltage supplied from input / output device 30 to dual-line converter 50. Hereinafter, the DC voltage supplied from input / output device 30 to dual-line converter 50 may sometimes be denoted as "supply voltage".

[0058] Here, in the present embodiment, based on the above low-current mode, the supply voltage of input / output device 30 is made variable, and a low-voltage mode in which operations are performed with a supply voltage value less than or equal to the standard voltage value, for example, a supply voltage value corresponding to 24 V, is further introduced.

[0059] According to the aspect of implementing the introduction of this low-voltage mode, instruments that can store the supply voltage at which operations can be performed in both input / output device 30 and dual-line converter 50. Hereinafter, the minimum value of the supply voltage that enables input / output device 30 or dual-line converter 50 to perform operations may sometimes be denoted as "minimum supply voltage value".

[0060] Based on the minimum supply voltage values respectively stored in the above input / output device 30 and dual-line converter 50, voltage adjustment unit 13 adjusts the supply voltage value that enables both input / output device 30 and dual-line converter 50 to perform operations.

[0061] More specifically, voltage adjustment unit 13 can perform the following processing when input / output device 30 and dual-line converter 50 are started. That is, voltage adjustment unit 13 supplies a standard voltage value, for example, a DC voltage of 24 V, from input / output device 30 to dual-line converter 50. Supplying the standard 24 V voltage immediately after startup has the aspect of suppressing a situation where dual-line converter 50 cannot perform operations before the adjustment of the supply voltage.

[0062] Moreover, when the voltage adjustment unit 13 stores the minimum supply voltage value in a register or the like of the input / output device 30, the supply of the DC voltage corresponding to the minimum supply voltage value is started from the input / output device 30 to the dual converter 50. The dual converter 50 outputs a fixed maximum current value in terms of the state where the voltage drop of the path is maximized. Then, the voltage adjustment unit 13 searches for the supply voltage value that enables both the input / output device 30 and the dual converter 50 to operate and is the lower limit.

[0063] As an example of such a method for searching for the supply voltage value, a linear search that sequentially searches for values from the beginning is cited, but this is only an example after all, and other search methods, such as a binary search that searches for values while narrowing the range by half, can also be applied to the search for the supply voltage value.

[0064] For example, until the OK flag indicating the condition that the supply voltage from the dual converter 50 to the input / output device 30 is OK is responded to, the voltage adjustment unit 13 executes a supply voltage adjustment process that repeatedly performs the following actions: updating the supply voltage value by adding a specified voltage value to the previous supply voltage value, and supplying the DC voltage corresponding to the updated supply voltage value. In addition, when the minimum supply voltage value is not stored in a register or the like of the input / output device 30, it is determined that the input / output device 30 can only operate with the standard supply voltage value, so the supply voltage is not adjusted.

[0065] Here, when supplying voltage from the input / output device 30 to the dual converter 50, the voltage adjustment unit 13 determines whether the dual converter 50 can operate with the supply voltage from the input / output device 30.

[0066] That is, when there is an equivalent resistance in the middle of the loop 3, the supply voltage from the input / output device 30 drops due to Ohm's law until it reaches the dual converter 50. As one aspect, the larger the equivalent resistance value, the larger the amount of supply voltage drop. As another aspect, the larger the current value, the larger the amount of supply voltage drop. The "equivalent resistance" mentioned here refers to a factor that can be regarded as equivalent to the actually existing resistance, such as wiring such as cables, contact resistance, or contact resistance. In addition, the equivalent resistance may not represent a resistance element. Sometimes, the equivalent resistance existing in the path from the input / output device 30 to the dual converter 50 on the loop 3 is denoted as "path resistance". According to the aspect of searching for the supply voltage value that enables the dual converter 50 to operate including the voltage drop based on this path resistance, when the voltage received on the dual converter 50 side satisfies the operable voltage, the OK flag is sent back to the input / output device 30 side.

[0067] Figure 4 This is a schematic diagram showing an example of path resistance. As Figure 4 shown, a supply voltage V1 is supplied from the input / output device 30, and the dual-line converter 50 outputs the maximum value of the current. In the supply voltage V1 supplied from the input / output device 30 in this way, a voltage drop V3 is generated due to the path resistance. As a result of the influence of this voltage drop V3, the voltage reaching the dual-line converter 50 is V1 - V3. Next, the voltage adjustment unit 13 compares the voltage value (V1 - V3) of the reaching voltage for the dual-line converter 50 with the minimum operating voltage V2 stored in a register or the like of the dual-line converter 50. For example, the voltage adjustment unit 13 determines whether the voltage value (V1 - V3) of the reaching voltage for the dual-line converter 50 is greater than or equal to the minimum operating voltage V2 of the dual-line converter 50, that is, whether (V1 - V3) ≥ V2.

[0068] Here, in the case of (V1 - V3) < V2, the dual-line converter 50 cannot perform an operation, and thus cannot respond with an OK flag. In this case, since the input / output device 30 cannot confirm the OK flag, an update to increase the supply voltage V1 is performed by adding a voltage value of, for example, 1 V or 3 V to the supply voltage V1 in any step amplitude, and a DC voltage corresponding to the updated supply voltage V1 is supplied. Then, at the stage where the reaching voltage (V1 - V3) for the dual-line converter 50 is greater than or equal to the minimum operating voltage V2 of the dual-line converter 50, the dual-line converter 50 can perform an operation. As a result, an OK flag is responded from the dual-line converter 50 to the input / output device 30. The supply voltage V1 that has responded with the OK flag in this way is determined as the adjustment result of the final supply voltage.

[0069] The setting unit 15 is a processing unit that performs various settings, such as settings for current output, supply voltage, transmission mode, etc. For example, when supplying a DC voltage corresponding to a standard supply voltage value at startup or after the voltage adjustment by the voltage adjustment unit 13, the setting unit 15 causes the communication unit 11 to perform digital communication to obtain the second current output range from the input / output device 30 and the dual-line converter 50, respectively.

[0070] As one aspect, when digital communication can be performed between the input / output device 30 and the dual-line converter 50, that is, in the automatic mode, the setting unit 15 performs automatic setting of any one of the following mode 1 to the following mode 4. That is, the setting unit 15 performs automatic setting of the following mode 1 to the following mode 4 based on whether the acquisition of the second current output range from both the input / output device 30 and the dual-line converter 50 is successful and whether there is information on the minimum supply voltage value in a register or the like of the input / output device 30.

[0071] (1) Setting of mode 1

[0072] For example, when it is successful to obtain the second current output range from both the input / output device 30 and the dual-line converter 50 and there is information on the minimum supply voltage value in the input / output device 30, the setting unit 15 sets the current output and supply voltage corresponding to Mode 1. For example, the setting unit 15 sets the larger of the two minimum current values, i.e., the minimum current value of the second current output range obtained from the input / output device 30 and the minimum current value of the second current output range obtained from the dual-line converter 50, as the current output of Mode 1. Figure 5 It is a diagram showing an example of current setting in the low current mode. In Figure 5 two current output ranges are exemplified, i.e., a current output range with a minimum value of 4 mA and a maximum value of 12 mA, and a current output range with a minimum current value of 3.6 mA and a maximum current value of 11 mA. In the Figure 5 example shown, the current output ranges in which both the input / output device 30 and the dual-line converter 50 can operate are as follows. That is, regarding the minimum current value, as a result of comparing the minimum current values of the two current output ranges, the larger minimum current value, i.e., 4 mA, is selected. On the other hand, regarding the maximum current value, as a result of comparing the maximum current values of the two current output ranges, the smaller maximum current value, i.e., 11 mA, is selected. And in the case of Mode 1, digital communication can be performed, so the current output is fixed at the minimum current value at which both can operate, "4 mA". Also, the setting unit 15 sets the supply voltage value obtained as the adjustment result of the voltage adjustment unit 13, i.e., the supply voltage value corresponding to the response OK flag, as the supply voltage of Mode 1. In addition, the setting unit 15 sets digital communication, such as HART communication, as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 1, etc., is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0073] Current output: The minimum current value of the second current output range (the larger of the two)

[0074] Supply voltage: The adjusted supply voltage value

[0075] Transmission method: HART communication

[0076] (2) Setting of Mode 2

[0077] In addition, when the second current output range is successfully obtained from both the input / output device 30 and the dual-line converter 50 and there is no information on the minimum supply voltage value in the input / output device 30, the setting unit 15 sets the current output and supply voltage corresponding to Mode 2. For example, the setting unit 15 sets the larger of the two minimum current values, which is the minimum current value of the second current output range obtained from the input / output device 30 and the minimum current value of the second current output range obtained from the dual-line converter 50, as the current output of Mode 2. Also, in Mode 2, power adjustment by the voltage adjustment unit 13 is not performed, so the setting unit 15 sets the standard supply voltage value, such as 24V, as the supply voltage of Mode 2. In addition to this, the setting unit 15 sets digital communication, such as HART communication, as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 2 is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0078] Current output: The larger of the two minimum current values of the second current output range

[0079] Supply voltage: Standard supply voltage value (24V)

[0080] Transmission method: HART communication

[0081] (3) Setting of Mode 3

[0082] In addition, when the acquisition of the second current output range fails from either the input / output device 30 or the dual-line converter 50 and there is information on the minimum supply voltage value in the input / output device 30, the setting unit 15 sets the current output and supply voltage corresponding to Mode 3. For example, the setting unit 15 sets the minimum current value of the first current output range, that is, the minimum current value of the instrument unified signal, which is 4mA, as the current output of Mode 3. Also, the setting unit 15 sets the supply voltage value obtained as the adjustment result of the voltage adjustment unit 13, that is, the supply voltage value corresponding to the response OK flag, as the supply voltage of Mode 3. In addition to this, the setting unit 15 sets digital communication, such as HART communication, as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 3 is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0083] Current output: 4mA

[0084] Supply voltage: Adjusted supply voltage value

[0085] Transmission method: HART communication

[0086] (4) Setting of Mode 4

[0087] In addition, when obtaining the second current output range fails from either the input / output device 30 or the two-wire converter 50 and there is no information on the minimum supply voltage value in the input / output device 30, the setting unit 15 sets the current output and supply voltage corresponding to Mode 4. For example, the setting unit 15 sets the minimum current value of the first current output range, that is, the minimum current value of the instrument unified signal, which is 4 mA, as the current output of Mode 4. And in Mode 4, since the power adjustment of the voltage adjustment unit 13 is not implemented, the setting unit 15 sets the standard supply voltage value, for example, 24 V, as the supply voltage of Mode 4. In addition to this, the setting unit 15 sets digital communication, such as HART communication, as the transmission method between the input / output device 30 and the two-wire converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 4, etc., is registered in the registers of the input / output device 30 and the two-wire converter 50 respectively.

[0088] Current output: 4 mA

[0089] Supply voltage: Standard supply voltage value (24 V)

[0090] Transmission method: HART communication

[0091] In this way, in Modes 1 to 4, since both the input / output device 30 and the two-wire converter 50 have a digital communication function, a fixed value such as the minimum current value of the second current output range or the minimum current value of the instrument unified signal, which is 4 mA, is set as the current output. In this case, the measured value is transmitted from the two-wire converter 50 to the input / output device 30 through digital communication. Thereby, compared with the case of implementing analog communication using a current signal, the power reduction effect can be improved.

[0092] As another aspect, when digital communication cannot be performed between the input / output device 30 and the two-wire converter 50, that is, in the wizard mode, the setting unit 15 performs manual setting of any one of the following Mode 5 to the following Mode 8. That is, the setting unit 15 performs automatic setting of the following Mode 5 to the following Mode 8 by making an operation input on whether there is a second current output range in both the input / output device 30 and the two-wire converter 50 and an operation input on whether there is information on the minimum supply voltage value in the registers of the input / output device 30, etc. Such an operation input can be accepted via the operation unit of the input / output device 30 or the two-wire converter 50 or a calibration work device that can be connected to the input / output device 30 or the two-wire converter 50.

[0093] (5) Setting of Mode 5

[0094] For example, when an operation input that causes a second current output range to exist in both the input / output device 30 and the dual-line converter 50 and an operation input that causes the lowest supply voltage value to exist in the input / output device 30 are received, the setting unit 15 sets the current output and supply voltage corresponding to Mode 5. For example, the setting unit 15 receives an operation input with the common range where the two second current output ranges defined in the input / output device 30 and the second current output range defined in the dual-line converter 50 overlap as the current output range in which both the input / output device 30 and the dual-line converter 50 can operate, and sets the received common range of the operation input as the current output of Mode 5. For example, in the Figure 5 example shown, as a result of the comparison of the minimum current value and the maximum current value, the two current output ranges of the 4 mA - 12 mA current output range and the 3.6 mA - 11 mA current output range overlap in the range of 4 mA - 11 mA. In this case, the common range of 4 mA - 11 mA is set as the current output of Mode 5. And the setting unit 15 sets the supply voltage value obtained as the adjustment result of the voltage adjustment unit 13, that is, the supply voltage value corresponding to the response OK flag, as the supply voltage of Mode 5. In addition, the setting unit 15 sets analog communication using a current signal as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 5, etc., is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0095] Current output: Common range of two second current output ranges

[0096] Supply voltage: Adjusted supply voltage value

[0097] Transmission method: Analog communication

[0098] (6) Setting of Mode 6

[0099] In addition, when an operation input that causes the second current output range to exist in both the input / output device 30 and the dual-line converter 50 and an operation input that causes the information on the minimum supply voltage value not to exist in the input / output device 30 are received, the setting unit 15 sets the current output and supply voltage corresponding to Mode 6. For example, the setting unit 15 takes the common range where the two second current output ranges defined in the input / output device 30 and the second current output range defined in the dual-line converter 50 overlap as the current output range in which both the input / output device 30 and the dual-line converter 50 can operate, receives the operation input, and sets the received common range as the current output of Mode 6. Further, in Mode 6, power adjustment by the voltage adjustment unit 13 is not performed, so the setting unit 15 sets the standard supply voltage value, such as 24V, as the supply voltage of Mode 6. In addition to this, the setting unit 15 sets analog communication using a current signal as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, transmission method, etc. of the above-mentioned Mode 6 is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0100] Current output: Common range of two second current output ranges

[0101] Supply voltage: Standard supply voltage value (24V)

[0102] Transmission method: Analog communication

[0103] (7) Setting of Mode 7

[0104] In addition, when an operation input that causes the second current output range not to exist in one of the input / output device 30 and the dual-line converter 50 and an operation input that causes the information on the minimum supply voltage value to exist in the input / output device 30 are received, the setting unit 15 sets the current output and supply voltage corresponding to Mode 7. For example, the setting unit 15 sets the first current output range corresponding to the instrument unified signal, that is, 4 - 20mA, as the current output of Mode 7. Further, the setting unit 15 sets the supply voltage value obtained as a result of the adjustment by the voltage adjustment unit 13, that is, the supply voltage value in response to the OK flag, as the supply voltage of Mode 7. In addition to this, the setting unit 15 sets analog communication using a current signal as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, transmission method, etc. of the above-mentioned Mode 7 is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0105] Current output: 4 - 20mA

[0106] Supply voltage: Adjusted supply voltage value

[0107] Transmission method: Analog communication

[0108] (8) Setting of Mode 8

[0109] In addition, when an operation input that makes the second current output range not exist in one of the input / output device 30 and the dual-line converter 50 and an operation input that makes the minimum supply voltage value not exist in the input / output device 30 are received, the setting unit 15 sets the current output and supply voltage corresponding to Mode 8. For example, the setting unit 15 sets the first current output range corresponding to the instrument unified signal, that is, 4 - 20 mA, as the current output of Mode 8. And in Mode 8, since the power adjustment of the voltage adjustment unit 13 is not implemented, the setting unit 15 sets the standard supply voltage value, for example, 24 V, as the supply voltage of Mode 8. In addition to this, the setting unit 15 sets analog communication using a current signal as the transmission method between the input / output device 30 and the dual-line converter 50. The current / voltage setting including the current output, supply voltage, and transmission method of the above-mentioned Mode 8, etc., is registered in the registers of the input / output device 30 and the dual-line converter 50 respectively.

[0110] Current output: 4 - 20 mA

[0111] Supply voltage: Standard supply voltage value (24 V)

[0112] Transmission method: Analog communication

[0113] The operation control unit 17 is a functional unit for controlling the operation of the input / output device 30 or the dual-line converter 50. As one aspect, the operation control unit 17 executes operations such as the current output, supply voltage, and transmission of the input / output device 30 or the dual-line converter 50 according to the current / voltage setting registered by the setting unit 15, that is, the setting of any one of Mode 1 to Mode 8.

[0114] <Specific examples of power reduction effect>

[0115] Next, use Figures 6 - 8 To illustrate specific examples of the power reduction effect of different modes. Figure 6 Is a diagram showing the power reduction effect of different modes. Figure 7 Is a schematic diagram showing the operation example of Mode 8. Figure 8 Is a schematic diagram showing the operation example of Mode 1.

[0116] In Figure 6 And Figure 8Examples of the second current output ranges of Mode 1, Mode 2, Mode 5, and Mode 6 corresponding to the low current mode are shown as 4 - 12 mA. The minimum current value can be any value less than or equal to 4 mA, and if the maximum current value exceeds the minimum current value, it can be any value less than 20 mA. Also, in Figure 6 and Figure 8 Examples of the adjusted supply voltage value of Mode 1, Mode 3, Mode 5, and Mode 7 corresponding to the low voltage mode are shown as 19 V, but this is just an example and the supply voltage value can also be adjusted to be less than 19 V. Additionally, Figure 6 and Figure 8 For ease of explanation, one example where the second power output range is uniformly 4 - 12 mA is listed, but of course, multiple different second power output ranges such as 4 - 12 mA and 3.6 - 12 mA can be separately maintained in the input / output device 30 and the two-wire converter 50.

[0117] Regarding Mode 8 among the above Modes 1 - 8, the current output range of the instrument unified signal, i.e., 4 - 20 mA, is set, and the supply voltage value of 24 V is set as the standard. Thus, Mode 8 corresponds to the current operation example that does not conform to either the low current mode or the low voltage mode. In the case of Mode 8, as Figure 7 shown, a DC voltage of 24 V is supplied from the input / output device 30 to the two-wire converter 50, so that the two-wire converter 50 operates with the DC voltage of 24 V. And in the case of Mode 8, the two-wire converter 50 converts the measured value obtained by measuring physical quantities such as flow rate and pressure difference into a current value within the current output range of the instrument unified signal, i.e., 4 - 20 mA, and transmits this current value to the input / output device 30 via Loop 3.

[0118] On the other hand, Modes 1 - 7 correspond to either the low current mode or the low voltage mode, and thus correspond to the operation examples of this embodiment. Taking the operation of Mode 1 among the above Modes 1 - 7 as an example. Taking the example of Mode 1 as Figure 8 shown, the minimum current value of the second current output range stored in the registers of both the input / output device 30 and the two-wire converter 50, i.e., the fixed value of 4 mA, is set as the current output. And in Figure 8 the case of Mode 1 as shown, as a result of the voltage adjustment between the input / output device 30 and the two-wire converter 50, the supply voltage value equal to the lowest supply voltage value, i.e., 19 V, is set as the supply voltage. As a result, a DC voltage of 19 V is supplied from the input / output device 30 to the two-wire converter 50, so that the two-wire converter 50 operates with the DC voltage of 19 V. And the two-wire converter 50 transmits the measured value obtained by measuring physical quantities such as flow rate and pressure difference to the input / output device 30 through digital communication.

[0119] Here, in terms of comparing the current operation example, i.e., the 4 - 20 mA current output, the 24 V supply voltage, and the operation example of this embodiment, Figure 6 the following example is shown. That is, the maximum power consumption of mode 8 is set as the reference value, and the maximum power consumption reduction value is calculated by subtracting the maximum power consumption of each of modes 1 - 7 from this reference value. The ratio of the reduction value to the reference value is derived as the power reduction effect.

[0120] As Figure 6 shown, the power reduction effects of mode 1 and mode 3 in modes 1 - 7 are the largest, and a power reduction effect of - 84% can be expected. Next, the power reduction effects of mode 2 and mode 4 are as follows, and a power reduction effect of - 80% can be expected. From the arrangement order of the above - mentioned modes, it can be known that the power reduction effect of the mode in which the current output is fixed at one value, i.e., the minimum current value or 4 mA, and the measured value is transmitted through digital communication is higher than that of other modes.

[0121] <Processing Flow>

[0122] Next, the processing flow of the setting device 10 related to this embodiment will be described. Figure 9 And Figure 10 are flowcharts showing the flow of the setting process. As an example, this process can start when the input - output device 30 and the dual - line converter 50 are started.

[0123] As Figure 9 shown, the voltage adjustment unit 13 supplies a standard voltage value, for example, a 24 V DC voltage, from the input - output device 30 to the dual - line converter 50 (step S101).

[0124] Then, when digital communication can be performed between the input - output device 30 and the dual - line converter 50, i.e., in the automatic mode (Yes in step S102), the setting unit 15 performs automatic setting of any one of the above - mentioned modes 1 - the above - mentioned mode 4.

[0125] That is, when the acquisition of the second current output range from both the input / output device 30 and the dual-line converter 50 is successful and information on the minimum supply voltage value exists in the input / output device 30 (Yes in step S103 and Yes in step S104), the voltage adjustment unit 13 performs a supply voltage adjustment process for adjusting the supply voltage between the input / output device 30 and the dual-line converter 50 (step S105). Through this supply voltage adjustment process, the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to operate and is the lower limit is searched for. On this basis, the setting unit 15 sets the current output and the supply voltage corresponding to the above-described mode 1 (step S106).

[0126] In addition, when the acquisition of the second current output range from both the input / output device 30 and the dual-line converter 50 is successful and information on the minimum supply voltage value does not exist in the input / output device 30 (Yes in step S103 and No in step S104), the setting unit 15 sets the current output and the supply voltage corresponding to the above-described mode 2 (step S107).

[0127] In addition, when the acquisition of the second current output range from one of the input / output device 30 and the dual-line converter 50 fails and information on the minimum supply voltage value exists in the input / output device 30 (No in step S103 and Yes in step S108), the voltage adjustment unit 13 performs a supply voltage adjustment process for adjusting the supply voltage between the input / output device 30 and the dual-line converter 50 (step S105). Through this supply voltage adjustment process, the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to operate and is the lower limit is searched for. On this basis, the setting unit 15 sets the current output and the supply voltage corresponding to the above-described mode 3 (step S109).

[0128] In addition, when the acquisition of the second current output range from one of the input / output device 30 and the dual-line converter 50 fails and information on the minimum supply voltage value does not exist in the input / output device 30 (No in step S103 and No in step S108), the setting unit 15 sets the current output and the supply voltage corresponding to the above-described mode 4 (step S110).

[0129] On the other hand, when digital communication cannot be performed between the input / output device 30 and the dual-line converter 50, that is, in the case of the wizard mode (No in step S102), manual setting of any one of the above-described modes 5 to 8 is performed.

[0130] As Figure 10As shown, when an operation input that causes a second current output range to exist in both the input / output device 30 and the dual-line converter 50 and an operation input that causes the lowest supply voltage value to exist in the input / output device 30 are received (Yes in step S111 and Yes in step S112), the voltage adjustment unit 13 performs a supply voltage adjustment process of adjusting the supply voltage between the input / output device 30 and the dual-line converter 50 (step S105). Through this supply voltage adjustment process, the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to operate and is the lower limit is searched for. On this basis, the setting unit 15 sets the current output and the supply voltage corresponding to the above-mentioned mode 5 (step S113).

[0131] In addition, when an operation input that causes a second current output range to exist in both the input / output device 30 and the dual-line converter 50 and an operation input that causes the lowest supply voltage value not to exist in the input / output device 30 are received (Yes in step S111 and No in step S112), the setting unit 15 sets the current output and the supply voltage corresponding to the above-mentioned mode 6 (step S114).

[0132] In addition, when an operation input that causes one of the input / output device 30 and the dual-line converter 50 not to have the second current output range and an operation input that causes the lowest supply voltage value to exist in the input / output device 30 are received (No in step S111 and Yes in step S115), the voltage adjustment unit 13 performs a supply voltage adjustment process of adjusting the supply voltage between the input / output device 30 and the dual-line converter 50 (step S105). Through this supply voltage adjustment process, the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to operate and is the lower limit is searched for. On this basis, the setting unit 15 sets the current output and the supply voltage corresponding to the above-mentioned mode 7 (step S116).

[0133] In addition, when an operation input that causes one of the input / output device 30 and the dual-line converter 50 not to have the second current output range and an operation input that causes the lowest supply voltage value not to exist in the input / output device 30 are received (No in step S111 and No in step S115), the setting unit 15 sets the current output and the supply voltage corresponding to the above-mentioned mode 8 (step S117).

[0134] <Summary of Embodiment 1>

[0135] As described above, the setting device 10 according to the present embodiment sets the current output corresponding to either the standard mode or the low current mode based on whether the second current output range is successfully obtained from the input / output device 30 and the dual-line converter 50. Therefore, when the low current mode is introduced, the instruments of both the input / output device 30 and the dual-line converter 50 can operate normally, so the introduction of the low current mode can be achieved. Therefore, according to the setting device 10 of the present embodiment, the low power consumption of the loop can be realized.

[0136] Moreover, the setting device 10 according to the present embodiment performs adjustment to decrease from the standard supply voltage value, that is, 24V, between the input / output device 30 and the dual-line converter 50, and sets the adjusted supply voltage value as the supply voltage. Therefore, the introduction of the low voltage mode can be achieved. Therefore, according to the setting device 10 of the present embodiment, the low power consumption of the loop can be realized.

[0137] <Embodiment 2>

[0138] Next, a functional structure example in the case where the setting functions described in the above Embodiment 1 are respectively mounted on the input / output device 30 and the dual-line converter 50 will be described.

[0139] <Structure of Input / Output Device 30>

[0140] Figure 11 is a block diagram showing a functional structure example of the input / output device 30 and the converter 50. In Figure 11 the modules associated with the setting function of the input / output device 30 are schematically shown, and the modules associated with the setting function of the converter 50 are schematically shown. In addition, in Figure 11 the solid lines connecting the modules only exemplarily show the correlations such as the causal relationship and the input / output relationship between the functions, and do not necessarily represent the wiring connecting the physical structure elements to each other.

[0141] As Figure 11 shown, the input / output device 30 includes a communication unit 31, a storage unit 32, a voltage adjustment unit 33, a receiving unit 34, a query unit 35A, a setting unit 35, and an operation control unit 37.

[0142] The communication unit 31 corresponds to Figure 1 the communication unit 11 shown, and performs digital communication with the dual-line converter 50. As an example, this digital communication can be realized by a hybrid communication method such as HART that superimposes a digital signal on an analog signal transmitted via the loop 3.

[0143] The storage unit 32 is a functional unit that stores various types of information. As an example, the storage unit 32 can be implemented by a register, a buffer, etc. It is not limited to the memory inside such a processor, and the storage unit 32 can also be implemented by other storage devices such as a main memory, a non-volatile memory, and a storage device.

[0144] The voltage adjustment unit 33 corresponds to Figure 1 the voltage adjustment unit 13 shown, and performs adjustment of the supply voltage from the input / output device 30 to the dual-line converter 50. As an example, when the input / output device 30 starts up, the voltage adjustment unit 33 supplies a standard voltage value, for example, a DC voltage of 24V, to the dual-line converter 50. Moreover, when the minimum supply voltage value 32A is stored in the storage unit 32, the voltage adjustment unit 33 starts supplying a DC voltage corresponding to the minimum supply voltage value 32A. Then, the voltage adjustment unit 33 searches for the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to operate and is the lower limit. Such adjustment of the supply voltage value can be implemented by the above-mentioned linear search, for example. Until an OK flag indicating a supply voltage OK condition is received from the dual-line converter 50, the voltage adjustment unit 33 repeatedly performs the following processing: updating the supply voltage value by adding a specified voltage value to the previous supply voltage value, and sending a supply voltage confirmation signal to confirm whether the dual-line converter 50 can operate by supplying a DC voltage corresponding to the updated supply voltage value. In addition, when the minimum supply voltage value 32A is not stored in the storage unit 32, it is determined that the input / output device 30 can only operate with the standard supply voltage value, so the supply voltage adjustment is not performed.

[0145] The receiving unit 34 is a processing unit that receives an analog current signal via the loop 3. The received current value is output to the operation control unit 37.

[0146] The inquiry unit 35A is a processing unit that inquires the dual-line converter 50 about the second current output range. As an example, when starting up, the inquiry unit 35A starts processing when supplied with a DC voltage corresponding to the standard supply voltage value or after the voltage adjustment by the voltage adjustment unit 33. That is, the inquiry unit 35A sends a current value confirmation signal to the dual-line converter 50 via the communication unit 31. This current value confirmation signal includes the second current output range 32B stored in the storage unit 32 and a request to inquire about the second current output range 52B stored in the storage unit 52 of the dual-line converter 50.

[0147] The setting unit 35 corresponds to Figure 1Corresponding to the setting unit 15 shown, various settings of the input / output device 30 are performed, such as settings of current output, supply voltage, transfer mode, etc. Here, the setting unit 35 acquires the second current output range 32B stored in the storage unit 32 as the second current output range of the input / output device 30. On the other hand, the setting unit 35 acquires the second current output range 52B or no information included in the current value confirmation signal received as a response to the current value confirmation signal sent by the inquiry unit 35A as the second current output range of the two-wire converter 50. In addition, the settings of current output, supply voltage, and transfer mode corresponding to any one of modes 1 to 8 are implemented by the same logic as the Figure 1 setting unit 15 shown. Thus, current / voltage settings 32C such as current output, supply voltage, and transfer mode are registered in the storage unit 32.

[0148] The operation control unit 37 is a functional unit for controlling the overall operation of the input / output device 30. As an example, the operation control unit 37 performs operations corresponding to the current output, supply voltage, and transfer of the input / output device 30 according to the current / voltage setting 32C registered by the setting unit 35, that is, the setting of any one of modes 1 to 8.

[0149] As one aspect, when the current / voltage setting 32C is any one of modes 1 to 4, the operation control unit 37 receives the measured value of the physical quantity via the digital communication of the communication unit 31.

[0150] As another aspect, when the current / voltage setting 32C is any one of modes 5 to 8, the operation control unit 37 digitizes the current value received via the receiving unit 34 based on the numerical range of the minimum current value and the maximum current value registered as the current / voltage setting 32C and transmits it to the system 70. For example, in the case of setting the low current mode, the operation control unit 37 implements the following plan: assign the minimum current value of the current / voltage setting 32C to the minimum current value of the numerical range of the standard mode, and assign the maximum current value of the current / voltage setting 32C to the maximum current value of the numerical range of the standard mode. For example, in the case of the 4 - 12 mA low current mode, if the operation control unit 37 receives a current value of 12 mA via the receiving unit 34, it is converted into a current value of 20 mA and the digital signal is output to the system 70.

[0151] By implementing such a program, on the system 70 side, it is possible to receive a current value at a level of 4 - 20 mA corresponding to the numerical range of the standard mode. Therefore, regarding the system 70, even without implementing the program between the low - current mode and the standard mode, it is possible to convert the current value received from the input / output device 30 into a process value from 0% to 100%. Therefore, it is possible to omit the structural changes in terms of hardware and software on the system 70 side.

[0152] <Structure of the two - wire converter 50>

[0153] As Figure 11 shown, the two - wire converter 50 has a communication unit 51, a storage unit 52, a voltage adjustment unit 53, a transmission unit 54, a response unit 55A, a setting unit 55, a measurement unit 56, and an operation control unit 57.

[0154] The communication unit 51 corresponds to Figure 1 the communication unit 11 shown, and performs digital communication with the input / output device 30. As an example of this digital communication, it can be implemented by a hybrid communication method such as HART that superimposes a digital signal on an analog signal transmitted via the loop 3.

[0155] The storage unit 52 is a functional unit for storing various information. As an example, the storage unit 52 can be implemented by a register, a buffer, etc. It is not limited to the memory inside such a processor, and the storage unit 52 can also be implemented by other storage devices such as a main memory, a non - volatile memory, and a storage.

[0156] The voltage adjustment unit 53 corresponds to Figure 1 the voltage adjustment unit 13 shown, and performs adjustment of the supply voltage from the input / output device 30 to the two - wire converter 50. As an example, the voltage adjustment unit 53 starts by supplying a standard voltage value, for example, a DC voltage of 24V, from the voltage adjustment unit 33 of the input / output device 30. At this time, the voltage adjustment unit 53 outputs a fixed maximum current value in terms of the state where the voltage drop of the path is maximized. Then, when supplying voltage from the input / output device 30 to the two - wire converter 50, the voltage adjustment unit 53 determines whether the voltage value of the arrival voltage reaching the two - wire converter 50 is greater than or equal to the minimum operation voltage 52A stored in the storage unit 52. At this time, when the voltage value of the arrival voltage for the two - wire converter 50 is greater than or equal to the minimum operation voltage 52A, it is determined that the two - wire converter 50 can perform an operation. In this case, the voltage adjustment unit 53 responds with an OK flag to the input / output device 30.

[0157] The transmission unit 54 is a processing unit that transmits an analog current signal via the loop 3. As an example, the transmission unit 54 generates a current value corresponding to an instruction at a timing corresponding to the instruction according to an instruction from the operation control unit 57.

[0158] The response unit 55A is a processing unit that responds to the second current output range of the two-wire converter 50 to the input / output device 30. As an example, the response unit 55A starts processing when a DC voltage corresponding to a standard supply voltage value is supplied at startup or after the voltage adjustment by the voltage adjustment unit 53. That is, the response unit 55A receives a current value confirmation signal including the second current output range 32B of the input / output device 30 and a request to query the second current output range of the two-wire converter 50 via the communication unit 51. At this time, when the second current output range 52B is registered in the storage unit 52, the response unit 55A returns a current value response signal including the second current output range 52B. On the other hand, when the second current output range 52B is not registered in the storage unit 52, the response unit 55A returns a current value response signal including the situation that the second current output range 52B is not available.

[0159] The setting unit 55 corresponds to Figure 1 the setting unit 15 shown, and performs various settings of the two-wire converter 50, such as current output, supply voltage, transmission mode, etc. Here, the setting unit 55 acquires the second current output range 52B stored in the storage unit 52 as the second current output range of the two-wire converter 50. On the other hand, the setting unit 55 acquires the second current output range 32B or no information included in the current value confirmation signal received by the response unit 55A as the second current output range of the input / output device 30. In addition, according to the same logic as the setting unit 15 shown in Figure 1 the setting unit 15 shown, the current output, supply voltage, and transmission mode corresponding to any one of the modes 1 to 8 are set. Thereby, the current / voltage settings 52C such as current output, supply voltage, and transmission mode are registered in the storage unit 52.

[0160] The measurement unit 56 is a processing unit that measures physical quantities such as differential pressure, temperature, and flow rate. The measured values are output to the operation control unit 57.

[0161] The operation control unit 57 is a functional unit that controls the overall operation of the two-wire converter 50. As an example, the operation control unit 57 performs operations corresponding to the current output, supply voltage, and transmission of the two-wire converter 50 according to the current / voltage settings 52C registered by the setting unit 55, that is, the settings of any one of the modes 1 to 8.

[0162] As one aspect, when the current / voltage setting 52C is any one of modes 1 to 4, the operation control unit 57 transmits the measured value measured by the measurement unit 56 to the input / output device 30 via digital communication of the communication unit 51. As another aspect, when the current / voltage setting 52C is any one of modes 5 to 8, the operation control unit 57 converts the measured value measured by the measurement unit 56 into a current value based on the numerical range of the minimum current value and the maximum current value registered as the current / voltage setting 52C. The transmission unit 54 is instructed to transmit the thus-converted current value.

[0163] <Sequence of operations>

[0164] Next, the operations of the input / output device 30 and the dual-line converter 50 will be described. Figure 12 It is a sequence diagram showing the operations of the input / output device 30 and the dual-line converter 50. As Figure 12 shown, at startup, the voltage adjustment unit 33 of the input / output device 30 supplies a standard voltage value, for example, a DC voltage of 24V, to the dual-line converter 50 (step S301). The process of this step S301 corresponds to Figure 9 the process of step S101 shown.

[0165] Next, the inquiry unit 35A of the input / output device 30 transmits a current value confirmation signal including the second current output range 32B stored in the storage unit 32 and a request to inquire about the second current output range 52B stored in the storage unit 52 of the dual-line converter 50 to the dual-line converter 50 via the communication unit 31 (step S302).

[0166] If such a current value confirmation signal is received by the dual-line converter 50, the response unit 55A of the dual-line converter 50 returns a current value response signal including the second current output range 52B or no information about the second current output range 52B to the input / output device 30 (step S303).

[0167] The processes of the above steps S302 and S303 correspond to Figure 9 the process of step S104 shown.

[0168] Moreover, the voltage adjustment unit 33 of the input / output device 30 performs the process of step S304 described below. That is, in step S304, the voltage adjustment unit 33 of the input / output device 30 supplies a DC voltage corresponding to the minimum supply voltage value and starts sending a supply voltage confirmation signal for confirming whether the dual-line converter 50 can perform an operation. Then, the voltage adjustment unit 33 of the input / output device 30 searches for the supply voltage value that enables both the input / output device 30 and the dual-line converter 50 to perform an operation and is the lower limit. As an example, this adjustment of the supply voltage value can be achieved by the above-mentioned linear search. For example, until an OK flag is responded from the dual-line converter 50 in step S305, the voltage adjustment unit 33 repeatedly performs the following process: updating the supply voltage value by adding a prescribed voltage value to the previous supply voltage value, and sending a supply voltage confirmation signal for confirming whether the dual-line converter 50 can perform an operation by supplying the DC voltage corresponding to the updated supply voltage value.

[0169] The processes of the above-mentioned step S304 and step S305 correspond to Figure 9 the process of step S105 shown.

[0170] If the adjustment of the supply voltage is completed in this way, the setting unit 35 of the input / output device 30 and the setting unit 55 of the dual-line converter 50 respectively set the current output, supply voltage, and transfer method corresponding to any one of the modes 1 to 8 (steps S306A and S306B).

[0171] The processes of the above-mentioned step S306A and step S306B correspond to Figure 9 and Figure 10 the processes of steps S104 to S117 shown, so the description thereof is omitted.

[0172] In addition, Figure 12 in the above, an example is given in which the supply voltage adjustment process performed in step S304 is achieved by linear search, but it is not limited thereto, and it can also be achieved by other search methods, such as binary search, etc.

[0173] <Summary of Embodiment 2>

[0174] As described above, the input / output device 30 and the dual-line converter 50 according to the present embodiment can, in the same manner as in the above Embodiment 1, achieve the introduction of the low-current mode and the introduction of the low-voltage mode. Therefore, according to the input / output device 30 and the dual-line converter 50 according to the present embodiment, the low power consumption of the loop can be achieved.

[0175] <Other Embodiments>

[0176] Next, the embodiments of the present invention have been described so far. However, the present invention can be applied to various applications, and in addition to the above-described embodiments, it can be implemented in various different ways.

[0177] <Application scope>

[0178] In the above-described Embodiment 1 and Embodiment 2, the two-wire converter 50 is exemplified. However, of course, the connection method of the converter is not limited to the two-wire type, and it can also be a three-wire type or a four-wire type.

[0179] Figure 13 It is a diagram showing an example of the application scope of the low current mode and the low voltage mode. As Figure 13 shown, compared with the two-wire type, the three-wire connection is different only in that both the converter 50 and the input / output device 30 are connected to the GND line, and the power consumption of the entire loop 3 is the same as that of the two-wire type. Therefore, the low current mode and the low voltage mode can also be applied in the three-wire type. Therefore, regarding the power reduction effect, the same effect as in the case of the two-wire type can be obtained (refer to Figure 6 ).

[0180] Compared with the two-wire type, the four-wire connection does not change in that the signal output line 3 for sharing the current value is provided between the input / output device 30 and the converter 50. Therefore, the low current mode can also be applied to the four-wire type. On the other hand, in the four-wire connection, the 24V power supply to the converter 50 is supplied from the external power supply 40, so a power supply line 5 is formed between the external power supply 40 and the converter 50. At this time, when the voltage of the external power supply 40 can be adjusted for each converter 50 connected to the external power supply 40, the low voltage mode (mode 5, mode 7) of the guidance mode can be applied. And the larger the range in which the voltage of the external power supply 40 can be adjusted, that is, the larger the range that can be reduced from 24V, the more the supply voltage value can be reduced in the low voltage mode. In addition, when digital communication can be achieved between the external power supply 40 and the converter 50, the low voltage mode (mode 1, mode 3) of the automatic mode can also be applied.

[0181] <Numerical values, etc.>

[0182] The matters described in the above embodiments, such as the number of two-wire converters 50 and specific examples such as the types of physical quantities to be measured, are just examples and can be changed. In addition, the processing order of the flowcharts described in the embodiments can also be changed within a non-contradictory range.

[0183] <System>

[0184] Regarding the information including the processing flow, control flow, specific names, various data, and parameters shown in the above description and in the drawings, except for the specially described cases, it can be arbitrarily changed. For example, any one or more than one of the functional units in the communication unit 11, voltage adjustment unit 13, setting unit 15, and operation control unit 17 can be constituted by different devices.

[0185] In addition, each structural element of each device shown in the figure is a functional concept, and physically it is not necessarily constituted as shown in the figure. That is, the specific ways of dispersion and integration of each device are not limited to the shown ways. That is, all or part of it can be dispersed / integrated functionally or physically in any unit according to various loads, usage conditions, etc. In addition, each structure can also be a physical structure.

[0186] Moreover, all or any part of each processing function performed by each device can be implemented by a CPU (Central Processing Unit) and a program parsed and executed by the CPU, or can be implemented as hardware based on wired logic.

[0187] <Hardware>

[0188] Next, a hardware structure example of the computer described in the embodiment will be described. Figure 14 It is a diagram showing a hardware structure example. As Figure 14 shown, the setting device 100 has a communication device 100a, a storage device 100b, a memory 100c, and a processor 100d. In addition, Figure 14 each part shown is connected to each other by a bus or the like.

[0189] The communication device 100a is a HART model or the like that superimposes a digital signal on an analog signal transmitted and received via the loop 3. The storage device 100b is a ROM, HDD, etc., and stores a program for performing the actions of the functions shown, data referred to by the program, etc. Figure 1 shown.

[0190] The processor 100d reads out from the storage device 100b or the like a program that performs the same processing as the processing unit shown in Figure 1 and expands it in the memory 100c, thereby causing the process of performing the functions described in Figures 9 - 10 etc. to execute actions. For example, this process performs the same functions as the processing unit of the setting device 10 shown in Figure 1 shown. Specifically, the processor 100d reads out from the storage device 100b or the like a program having the same functions as the communication unit 11, voltage adjustment unit 13, setting unit 15, and operation control unit 17, etc. Moreover, the processor 100d executes the following process, that is, executes the same processing as the communication unit 11, voltage adjustment unit 13, setting unit 15, and operation control unit 17, etc.

[0191] In this way, the setting device 100 acts as a setting device that reads and executes a program to execute the setting method. In addition, the setting device 100 can also read the above program from a recording medium by using a medium reading device and execute the read program, thereby realizing the same functions as those in the above embodiments. Furthermore, the program described in other embodiments is not limited to being executed by the setting device 100. For example, when the program is executed by other computers or servers, or when they cooperate to execute the program, the present invention can also be applied in the same way.

[0192] The above program can be distributed via a network such as the Internet. In addition, the above program can be recorded on any recording medium and read and executed by a computer from the recording medium. For example, the recording medium can be implemented by a hard disk, a floppy disk (FD), a CD-ROM, a MO (Magneto-Optical disk), a DVD (Digital Versatile Disc), etc.

[0193] <Others>

[0194] Several examples of combinations of the disclosed technical features are described below.

[0195] (1) A setting device, characterized in that

[0196] the setting device has:

[0197] a communication unit that performs communication to obtain a second current output range, which is a current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to a system, and has a smaller minimum current value or maximum current value than a first current output range; and

[0198] a setting unit that sets a current output corresponding to either the first current output range or the second current output range based on whether the acquisition of the second current output range is successful.

[0199] (2) The setting device according to (1), characterized in that when the acquisition of the second current output range is successful, the setting unit sets the larger of the two minimum current values, i.e., the minimum current value of the second current output range obtained from the input / output device and the minimum current value of the second current output range obtained from the transducer, as the current output of the transmission signal.

[0200] (3) The setting device according to (1) or (2), characterized in that, in the case where acquisition of the second current output range fails, the setting unit sets the minimum current value of the first current output range as the current output of the transmission signal.

[0201] (4) The setting device according to any one of (1) to (3), characterized in that, in the case where communication fails and acquisition of the second current output range fails, the setting unit accepts an operation input of a common range in which two second current output ranges, namely, the second current output range defined in the input / output device and the second current output range defined in the transducer, overlap with each other, and sets the common range that has accepted this operation input as the current output of the transmission signal.

[0202] (5) The setting device according to (4), characterized by further comprising a conversion unit that converts the current value of the transmission signal into a process value based on the minimum current value and the maximum current value of the second current output range set by the setting unit.

[0203] (6) The setting device according to any one of (1) to (5), characterized by further comprising a voltage adjustment unit that performs adjustment to make the supply voltage supplied from the input / output device to the transducer via the loop less than or equal to a standard supply voltage value and reduce it to a lower limit value at which the input / output device and the transducer can perform operations,

[0204] The setting unit sets the lower limit value of the supply voltage adjusted by the voltage adjustment unit as the supply voltage.

[0205] (7) The setting device according to (6), characterized in that the voltage adjustment unit searches for the lower limit value at which the input / output device and the transducer can perform operations by linear search or binary search.

[0206] (8) The setting device according to any one of (1) to (7), characterized in that the first current output range is 4 - 20 mA.

[0207] (9) The setting device according to any one of (1) to (8), characterized in that the communication is HART (Highway Addressable Remote Transducer).

[0208] (10) A setting method, characterized in that

[0209] The processor performs the following processing: Execute communication to obtain a second current output range, which is the current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to the system, and is smaller in minimum current value or maximum current value than a first current output range.

[0210] Based on whether the acquisition of the second current output range is successful, set a current output corresponding to either the first current output range or the second current output range.

[0211] (11) A setting program, characterized in that

[0212] Cause the processor to perform the following processing: Execute communication to obtain a second current output range, which is the current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to the system, and is smaller in minimum current value or maximum current value than a first current output range.

[0213] Based on whether the acquisition of the second current output range is successful, set a current output corresponding to either the first current output range or the second current output range.

[0214] Explanation of reference numerals

[0215] 10 Setting device

[0216] 11 Communication unit

[0217] 13 Voltage adjustment unit

[0218] 15 Setting unit

[0219] 17 Operation control unit

[0220] 30 Input / output device

[0221] 31 Communication unit

[0222] 32 Storage unit

[0223] 32A Minimum supply voltage value

[0224] 32B Second current output range

[0225] 32C Current / voltage setting

[0226] 33 Voltage adjustment unit

[0227] 34 Receiving unit

[0228] 35A Inquiry unit

[0229] 35 Setting Unit

[0230] 37 Action Control Unit

[0231] 50 Dual-line Converter

[0232] 51 Communication Unit

[0233] 52 Storage Unit

[0234] 52A Minimum Action Voltage

[0235] 52B Second Current Output Range

[0236] 52C Current / Voltage Setting

[0237] 53 Voltage Adjustment Unit

[0238] 54 Transmission Unit

[0239] 55A Response Unit

[0240] 55 Setting Unit

[0241] 56 Measurement Unit

[0242] 57 Action Control Unit

[0243] 70 System

Claims

1. A setting device, characterized in that: The setting device has: A communication unit that performs communication to obtain a second current output range, which is the current output range of a transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to a system, and has a smaller minimum current value or maximum current value compared to a first current output range; And A setting unit that sets a current output corresponding to either the first current output range or the second current output range based on whether the acquisition of the second current output range is successful.

2. The setting device according to claim 1, characterized in that: When the acquisition of the second current output range is successful, the setting unit sets the larger of the two minimum current values, which are the minimum current value of the second current output range obtained from the input / output device and the minimum current value of the second current output range obtained from the transducer, as the current output of the transmission signal.

3. The setting device according to claim 1, characterized in that: When the acquisition of the second current output range fails, the setting unit sets the minimum current value of the first current output range as the current output of the transmission signal.

4. The setting device according to claim 1, characterized in that: When the communication fails and the acquisition of the second current output range fails, the setting unit accepts an operation input for a common range in which two second current output ranges, namely the second current output range defined in the input / output device and the second current output range defined in the transducer, overlap, and sets the common range for which the operation input has been accepted as the current output of the transmission signal.

5. The setting device according to claim 4, characterized in that: The setting device further has a conversion unit that converts the current value of the transmission signal into a process value based on the minimum current value and the maximum current value of the second current output range set by the setting unit.

6. The setting device according to claim 1, characterized in that: The setting device further has a voltage adjustment unit that performs adjustment to make the supply voltage supplied from the input / output device to the transducer via the loop less than or equal to a standard supply voltage value and reduce it to the lower limit value at which the input / output device and the transducer can perform operations, The setting unit sets the lower limit value of the supply voltage adjusted by the voltage adjustment unit as the supply voltage.

7. The setting device according to claim 6, characterized in that: The voltage adjustment unit searches for the lower limit value at which the input / output device and the transducer can perform operations by linear search or binary search.

8. The setting device according to claim 1, characterized in that: The first current output range is 4 - 20 mA.

9. The setting device according to claim 1, characterized in that: The communication is HART, an addressable remote sensor data highway.

10. A setting method, characterized in that: The processor performs the following processing: Execute communication to obtain a second current output range, which is the current output range of the transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to the system, and the minimum current value or the maximum current value is smaller than that of the first current output range. Based on whether the acquisition of the second current output range is successful, set a current output corresponding to either the first current output range or the second current output range.

11. A computer-readable recording medium that records a setting program, characterized in that: The setting program causes a computer to perform the following processing: Execute communication to obtain a second current output range, which is the current output range of the transmission signal via a loop formed between a transducer that converts a physical quantity into a current value and an input / output device that outputs the current value input from the transducer to the system, and the minimum current value or the maximum current value is smaller than that of the first current output range. Based on whether the acquisition of the second current output range is successful, set a current output corresponding to either the first current output range or the second current output range.

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