Control monitoring signal transmission system

Abstract

The present invention is provided with: a master station for transmitting and receiving data to and from a control unit; and a plurality of substations for transmitting and receiving data to and from the master station by means of a synchronous transmission system via a common transmission line. A control monitoring data area, which is assigned to each of the substations in a data transmission direction determined, and a management data area, which is different from the control monitoring data area and is used for transmitting and receiving data to and from all of the substations, are provided. In the control monitoring data area, an address is set as a timing for acquiring a data area allocated to the slave station, the master station transmits a check identifier using the management data area at a timing after execution of a process for detecting the address, and the slave station transmits the check identifier to the slave station when receiving the check identifier. When an operation identifier is transmitted from the master station, data transmission and reception using the control monitoring data area are enabled, the verification identifier is recorded and stored, and when the operation identifier is transmitted from the master station, data transmission and reception using the control monitoring data area are enabled or disabled on the basis of the verification result of the operation identifier and the verification identifier.

Description

Technical Field

[0001] The present invention relates to a control monitoring signal transmission system, which reduces the wiring of signal lines between a master station arranged on the control side and a plurality of substations arranged on the controlled side, connects them through a common transmission line, and transmits data by a transmission synchronization method such as synchronization with a transmission frequency. Background Art

[0002] In a control system that centrally controls multiple devices arranged in a facility, reducing the number of wiring, i.e., so-called wire saving, is widely implemented. Moreover, as for the general wire saving method, instead of the parallel connection method in which multiple devices arranged on the controlled side are directly connected to the control unit arranged on the control side, a method in which a master station and multiple substations having a parallel signal and serial signal conversion function are respectively connected to the control unit and the multiple devices, and data is transmitted and received between the master station and the multiple substations by serial signals through a common transmission line is widely used. Furthermore, as a method of transmitting and receiving data by serial signals through a common transmission line, a transmission synchronization method such as synchronization with a transmission frequency is widely used.

[0003] As a method of transmitting and receiving data by serial signals through a common transmission line, there is a known transmission synchronization method such as synchronization with a transmission frequency. In addition, a method of transmitting and receiving data between a master station and a plurality of slave stations by synchronizing with a serial pulse signal (hereinafter referred to as a transmission frequency signal) is widely used.

[0004] In the method of transmitting and receiving data by synchronizing with the transmission frequency signal, the frame repeatedly transmitted by the master station is divided by time, and a data area is allocated to each of the plurality of slave stations in which the transmission direction of the data is determined (transmission from the master station to the slave station or transmission from the slave station to the master station), and the data is overlapped in the data area. Furthermore, each slave station is set with an address value for obtaining the timing of the data area allocated to the self-station, and the plurality of slave stations transmit and receive data with the master station in the data area allocated to each of the plurality of slave stations, so as to prevent the collision of the transmission and reception signals of the plurality of slave stations.

[0005] On the other hand, the address set in the substation can also be used for purposes other than preventing conflicts in the transmission and reception of multiple substations. For example, in the remote control wiring inspection system disclosed in Japanese Patent Publication No. 2011-114449 proposed by the applicant of this case, in addition to the data area allocated to each substation, a common data area (hereinafter referred to as the management data area) used for data transmission and reception with all substations is used, so that the wiring connection status between the substation and the controlled device can be directly checked on the master station side without moving to the remote site where the line is connected.

[0006] [Prior art literature] 〔Patent Document〕 [Patent Document 1] Japanese Patent No. 2011-114449 Summary of the invention

[0007] [Problems to be solved by the invention] However, in a method in which a plurality of substations transmit and receive data with a master station in a data area assigned to each substation and an address numerically expressing the timing for obtaining the data area assigned to each substation is set, if a control object device machine set on the controlled side is changed and becomes a state including a substation whose address is not recognized by the master station, the device machine associated with the substation whose address is not recognized may malfunction.

[0008] For example, if an address that overlaps with an address corresponding to a data area assigned to an existing substation is accidentally set in a state where the address is not recognized, since the address is not recognized substation also uses the data area to perform data transmission and reception, the device corresponding to the address is also operated. However, the operation of the device is not intentional, that is, it is an erroneous operation.

[0009] The present invention aims to provide a control monitoring signal transmission system that can prevent erroneous operation of a device associated with an unrecognized substation in a method of transmitting and receiving data by synchronizing a transmission frequency signal.

[0010] [Technical means to solve the problem] The control monitoring signal transmission system of the present invention includes: a main station, which transmits and receives data with a control unit; and a plurality of substations, which transmit and receive data with the main station through a common transmission line by synchronous transmission. The transmission and reception of data between the main station and the substations is performed by overlapping the data in a frame repeatedly sent from the main station. The frame is divided by time and is provided with a control monitoring data area in which the data transmission direction is determined and allocated to each of the substations, and a management data area different from the control monitoring data area and used for data transmission and reception with all the substations. For each of the substations, a numerical value of an address is set in the control monitoring data area as a timing for obtaining the data area allocated to the station. The main station uses the management data area to send a verification identifier at a timing after the processing for detecting the address is executed. When the slave station receives the verification identifier, it enables data transmission and reception using the control monitoring data area and records and stores the verification identifier. When the operational identifier is sent from the main station, it enables or disables data transmission and reception using the control monitoring data area based on the verification result of the operational identifier and the verification identifier.

[0011] [Effects of the Invention] According to the present invention, since the substation enables data transmission and reception using the control monitoring data area when receiving the verification identifier sent from the main station at the timing for executing the processing of the processing identification address, the address unidentified substation that has not received the verification identifier will not use the control monitoring data area to transmit and receive data. Therefore, even if an address that overlaps with the address corresponding to the data area allocated to the existing substation is accidentally set to the address unidentified substation, it is possible to prevent the device associated with the address unidentified substation from erroneous operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 To show the system architecture diagram of the control monitoring signal transmission system of the present invention, Figure 1 (a) is the system architecture diagram before the change. Figure 1 (b) is the architecture diagram after the change; Figure 2 This is the functional block diagram of the main station; Figure 3 is a timing diagram of the transmission signal; Figure 4 A schematic diagram showing the transmission steps of a transmission signal; Figure 5 It is the functional block diagram of the input substation; Figure 6 It is the functional block diagram of the output substation; DETAILED DESCRIPTION

[0013] An implementation of the control monitoring signal transmission system of the present invention is described.

[0014] This control monitoring signal transmission system is used to centrally control multiple devices and machines in factories and other facilities. Figure 1 As shown, the control unit 1 and the main station 2 connected to the common data signal lines DP and DN (hereinafter also referred to as transmission lines) are composed of a plurality of input substations 4, output substations 5, and input / output substations 6 arranged in the facility to be controlled and connected to the transmission lines. In addition, the type and number of substations connected to the transmission lines can be appropriately determined according to the state of use of the system. Figure 1 In order to simplify the diagram, not all the substations that make up the system are shown.

[0015] The input unit 7 connected to the input substation 4, the output unit 8 connected to the output substation 5, and the input / output unit 9 connected to the input / output substation 6 are devices arranged in a facility to be controlled.

[0016] As what corresponds to the input unit 7, for example, a reed switch, a micro switch, a push button switch, a photoelectric switch, and other various sensors can be cited, but the present invention is not limited to these.

[0017] Examples of the object corresponding to the output unit 8 include an actuator, a (stepping) motor, a solenoid, a solenoid valve, a relay, a thyristor, and a lamp, but the object is not limited thereto.

[0018] The input / output unit 9 is a device having the functions of both the input unit 7 and the output unit 8. Examples of such devices include temperature control, timers, and counters, which have both the function of transmitting information to the master station 2 and the function of performing output operations based on data sent from the master station 2.

[0019] In addition, the input unit 7 may be an input unit integrated substation 70 integrated with the input substation 4 . Furthermore, the output unit 8 may be an output unit integrated substation 80 integrated with the output substation 5 .

[0020] The control unit 1 includes a management judgment mechanism 11 having a calculation function and an input / output unit 12. The management judgment mechanism 11 receives data from the main station through the input / output unit 12 and performs necessary calculation processing based on a program recorded inside.

[0021] <Master Site Architecture> The master station 2 is connected to the transmission line, such as Figure 2 As shown, it has an output data unit 21, a management data unit 22, a timing generating unit 23, a master station output unit 24, a master station input unit 25, and an input data unit 26. In addition, while superimposing the control data on a voltage frequency signal having a specified period and duty ratio and transmitting it, it captures the monitoring data transmitted from the input substation 4, the output substation 5, and the input-output substation 6 (hereinafter also expressed as "substations 4, 5, 6") and outputs it to the input-output unit 12 of the control unit 1.

[0022] The data output unit 21 delivers the data received from the control unit 1 to the master output unit 24 as serial data.

[0023] The management data unit 22 delivers data necessary for instructing the slave station in a management control data area described later to the master station output unit 24 as serial data based on the data received from the control unit 1 .

[0024] The timing generating unit 23 is composed of an oscillation circuit 31 (OSC) 31 and a timing generating mechanism 32. Based on the oscillation circuit 31 (OSC), the timing generating mechanism 32 generates the timing frequency of this system and delivers it to the main station output unit 24 and the main station input unit 25.

[0025] The master station output section 24 is composed of a control data generating mechanism 33 and a line driver 34. The control data generating mechanism 33 sends a voltage frequency signal superimposed with control data to the transmission line through the line driver 34 based on the data received from the output data section 21 and the timing frequency received from the timing generating section 23.

[0026] In this embodiment, a voltage frequency signal that transmits the timing frequency by using a voltage change is used as the transmission frequency signal. However, the method of transmitting the timing frequency is not limited, and other methods suitable for the use situation can also be used.

[0027] The voltage frequency signal is composed of multiple frequency pulses. Figure 3 The transmission signal shown has a voltage level Ep higher than the threshold value Est (hereinafter referred to as "high potential period"). In this embodiment, the voltage level Ep is +24V.

[0028] Although the high potential period functions as a power supply voltage for synchronization frequency and communication, as long as these conditions are met, the pulse width or voltage level is not limited to this embodiment. It can be appropriately determined according to the use environment or use status. For example, it can also be a negative voltage lower than the ground level that is maintained for a specified time.

[0029] Each frequency pulse has a data pulse used for data transmission between the master station 2 and the slave stations 4, 5, 6.

[0030] In this embodiment, each data pulse represents a data value by a voltage level. However, the voltage level representing the data value can be appropriately determined according to the use environment or use state. For example, it can also be a negative voltage lower than the ground level.

[0031] The data pulse of this embodiment represents the data value by a voltage level lower than the voltage level Ep. Furthermore, the potential VL lower than the threshold value Ect is the voltage level representing the logic data value "1", and the potential VM higher than the threshold value Ect is the voltage level representing the logic data value "0". Furthermore, in this embodiment, although the threshold is set between 10V and the ground level (about 6V), its size is not limited and can also be set according to the use conditions or use environment. In addition, the corresponding relationship between the voltage level representing the data value and the logic data value is not limited and can also be set according to the use conditions or use environment.

[0032] In this embodiment, the data value can also be represented by the duration of the data pulse. In this embodiment, when the period from the rise of the high potential period to the rise of the next high potential period is one cycle t0, the period of the data pulse is (3 / 4) t0 to represent the logic data "1", and the period is (1 / 4) t0 to represent the logic data "0". As long as these periods are in accordance with the value of the control data input from the control unit 1, their lengths are not limited and can be freely determined.

[0033] The voltage frequency signal is a signal frame that is repeatedly sent from the master station 2 with a specified number of high voltage periods. Figure 4 As shown, a management data area and a control and monitoring data area are set in a single frame.

[0034] At the beginning of the frame, a start signal ST is sent, which has a high voltage period and a voltage level Ep maintained for a long time at a higher voltage period, as a separator of each frame. In addition, the length of the start signal ST is not limited as long as it can be distinguished from the high voltage period, and can be appropriately determined considering the use conditions.

[0035] The control monitoring data area, in which the designated area is respectively allocated to the substations 4, 5, and 6. And the control data from the main station 2 to the output substation 5 and the input-output substation 6 overlaps with the area allocated to the target substation, or the monitoring data from the input substation 4 and the input-output substation 6 to the main station 2 overlaps with the area allocated to the substation that sent the monitoring data. In this way, the control monitoring data area is used for stable data transmission and reception between the main station 2 and the substations 4, 5, and 6.

[0036] The management data area is used to control the monitoring data area and is used to send and receive unstable data that cannot be sent and received. The verification identifier and operation identifier of the present invention are sent using this management data area, and the sending procedure will be described in detail later.

[0037] The management data area is also used to perform processing for identifying the addresses of the slave stations 4, 5, and 6. Specifically, the master station 2 first specifies all the values ​​that may be set as the addresses of the slave stations 4, 5, and 6 in order. When the value specified in the management data area matches the address set in the slave station 4, 5, and 6, the slave station 4, 5, and 6 receiving this processing uses the management data area to send a response to the master station 2. And the master station 2 identifies the addresses of all the slave stations 4, 5, and 6 based on the presence or absence of this response. In other words, the existence of the slave station 4, 5, and 6 that has the value that has responded as the address is recognized.

[0038] The master station input unit 25 is composed of a line receiver 35 and a monitoring data acquisition mechanism 36. The line receiver 35 receives a voltage frequency signal from a transmission line, performs waveform shaping, and delivers the signal to the monitoring data acquisition mechanism 36.

[0039] The monitoring data acquisition mechanism 36 obtains the timing of acquiring the data value by using the timing frequency delivered from the timing generation unit 23, and acquires the data based on the digital value of the voltage level of the voltage frequency signal delivered from the line receiver 35. In addition, the stable data DIO overlapped in the control monitoring data area and the management data DEX overlapped in the management data area are delivered to the input data unit 26.

[0040] The input data unit 26 converts the serial input data received from the monitoring data acquisition mechanism 36 into parallel data, and outputs the parallel data to the input / output unit 12 of the control unit 1 as monitoring data and management monitoring data.

[0041] <Enter the architecture of the subsite> Enter substation 4, such as Figure 5 As shown, there is a substation input unit 40 that performs main calculation processing, and a substation line receiver 48 and a substation line driver 49 arranged between the substation input unit 40 and the transmission line. The substation line receiver 48 receives a voltage frequency signal from the transmission line, and the substation line driver 49 sends monitoring data.

[0042] The substation input unit 40 has a transmission and receiving mechanism 41, a management control data acquisition mechanism 42, an address acquisition mechanism 43, an address setting mechanism 44, a management monitoring data sending mechanism 45, an input mechanism 46, a monitoring data sending mechanism 47 and an identifier record checking mechanism 61.

[0043] In addition, the input substation 4 of this embodiment includes a micro control unit (MCU) as an internal circuit, and this MCU functions as a substation input unit 40.

[0044] The substation line receiver 48 receives the voltage frequency signal from the transmission line, shapes the waveform and delivers it to the transmission and reception mechanism 41.

[0045] The transmission and receiving mechanism 41 determines the threshold values ​​Est and Ect of the voltage level, and delivers the digital value of the voltage level of the voltage frequency signal delivered from the substation line receiver 48 to the management control data acquisition mechanism 42, the address acquisition mechanism 43 and the management monitoring data sending mechanism 45.

[0046] The management control data acquisition mechanism 42 determines the start signal ST based on the digital value of the voltage level of the voltage frequency signal. And takes the timing when the start signal ST ends (falls in this embodiment) as the starting point, and acquires the management data based on the digital value of the voltage level of the data IO area in the management data area. And, it is delivered to the processing mechanism for executing the processing based on the management data. In addition, Figure 5 In FIG. 1 , an identifier record checking unit 61 is shown as a processing unit when an identifier or an operation identifier is used as management data, but illustrations of other processing units are omitted.

[0047] The address acquisition mechanism 43 determines the start signal ST based on the digital value of the voltage level of the voltage frequency signal, and counts the high potential period starting from the timing when the start signal ST ends (falls in this embodiment). And the timing when the count value is consistent with the self-station address data set by the address setting mechanism 44 is obtained. In addition, this timing becomes the timing (hereinafter referred to as the "self-station area start timing") of the area allocated to the self-station in the control monitoring data area (hereinafter referred to as the "self-station area").

[0048] Then, the address acquisition mechanism 43 that obtains the start timing of the own station area activates the monitoring data transmission mechanism 47. When the own station area includes a plurality of data pulses, the monitoring data transmission mechanism 47 is activated until the end of the own station area.

[0049] The management monitoring data transmission unit 45 determines the start signal ST based on the digital value of the voltage level of the transmission signal, and outputs the monitoring data in the management data area in response to the demand, starting from the timing when the start signal ST ends.

[0050] The monitoring data transmitted from the management monitoring data transmitting means 45 is transmitted only when the data to be transmitted to the master station 2 is delivered from the processing means for executing processing based on the management data.

[0051] The input mechanism 46 delivers data based on the input from the input unit 7 to the monitoring data transmission mechanism 47 .

[0052] When the monitoring data transmission mechanism 47 is enabled by the identifier record checking mechanism 61, the data delivered from the input mechanism 46 when enabled by the address acquisition mechanism 43 is transmitted as monitoring data through the slave station line driver 49.

[0053] The identifier record verification mechanism 61 records and stores the verification identifier when the verification identifier is delivered from the management control data acquisition mechanism 42, and activates the monitoring data sending mechanism 47. When the operation identifier is delivered, the operation identifier is verified with the verification identifier. When the verification is performed and the operation identifier and the verification identifier are inconsistent, the monitoring data sending mechanism 47 is deactivated.

[0054] <Output Substation Architecture> Output substation 5, such as Figure 6As shown, there is a substation output unit 50 that performs the main operation processing, and a substation line receiver 48 and a substation line driver 49 arranged between the substation output unit 50 and the transmission line. The substation line receiver 48 receives the voltage frequency signal from the transmission line, and outputs the information based on the control data to the output unit 8 to operate or stop the output unit 8. When it is necessary to use the data transmission and reception of the management data area, the monitoring data is sent through the substation line driver 49. In addition, Figure 6 , parts substantially identical to those of the input substation 4 are indicated by the same symbols, and their descriptions are simplified or omitted.

[0055] The substation output unit 50 has a transmission and receiving mechanism 41, a management control data acquisition mechanism 42, an address acquisition mechanism 43, an address setting mechanism 44, a management monitoring data sending mechanism 45, a control data acquisition mechanism 51, an output mechanism 52 and an identifier record checking mechanism 61.

[0056] The output substation 5 of this embodiment is the same as the input substation 4 and includes a micro control unit (MCU) as an internal circuit. The MCU functions as a substation output unit 50.

[0057] The transmission receiving mechanism 41 of the output substation 5 delivers the digital value of the voltage level of the transmission signal delivered from the substation line receiver 48 to the management control data acquisition mechanism 42 , the address acquisition mechanism 43 , the management monitoring data sending mechanism 45 and the control data acquisition mechanism 51 .

[0058] When the address acquisition mechanism 43 of the output substation 5 obtains the start timing of the self-station area, the control data acquisition mechanism 51 is activated. When the self-station area includes multiple data IO areas, the control data acquisition mechanism 51 of the data IO area is activated each time a data IO area appears until the end of the self-station area.

[0059] When the control data acquisition mechanism 51 is enabled by the identifier record checking mechanism 61 , when the address acquisition mechanism 43 is enabled, the control data is acquired based on the digital value of the voltage level of the voltage frequency signal delivered from the transmission and reception mechanism 41 and delivered to the output mechanism 52 .

[0060] The output mechanism 52 outputs information based on the control data delivered from the control data acquisition mechanism 51 to the output unit 8 to operate or stop the output unit 8 .

[0061] The identifier record verification mechanism 61 of the substation output unit 5 records and stores the verification identifier when the verification identifier is delivered from the management control data acquisition mechanism 42, and activates the control data acquisition mechanism 51. When the operation identifier is delivered, the operation identifier is verified with the verification identifier. When the verification is performed and the operation identifier and the verification identifier are inconsistent, the control data acquisition mechanism 51 is disabled.

[0062] <Input and output substation architecture> The input / output substation 6 is a substation input / output unit having the functions of both the input substation 4 and the output substation 5, and having an architecture combining the substation input unit 40 and the substation output unit 50. However, since its architecture is substantially the same as that of the substation input unit 40 and the substation output unit 50, the illustration and description thereof are omitted.

[0063] <Procedure for sending verification identifier and operation identifier> Reference Figure 1 , explaining the procedure for sending verification identifiers and operation identifiers.

[0064] When executing the process for identifying the addresses of the slave stations 4, 5, and 6, the master station 2 transmits the verification identifier using the management data area for all the identified addresses.

[0065] The substations 4, 5, 6 receiving the verification identifier activate the monitoring data transmission mechanism 47 or the control data acquisition mechanism 51 as described above, and become capable of performing data transmission and reception with the main station 2 using the control monitoring data area (such as Figure 1 The state shown in (a)).

[0066] The verification identifier is recorded as non-volatile data in the substations 4, 5, and 6, and can be recorded and stored even when the system is stopped for maintenance or when it is not required to operate. In addition, when the system is operated again, the main station 2 uses the management data area to send the operation identifier to all the substations 4, 5, and 6. In addition, the timing of sending the operation identifier can be appropriate according to the usage status, etc. For example, it can be after a specified time has passed after restarting, or it can also be when the verification command is input.

[0067] The slave stations 4, 5, and 6 receiving the operation identifier perform verification as described above by the identifier record verification means 61. In this case, if the verification result is consistent, data transmission and reception with the master station 2 using the control monitoring data area can be performed.

[0068] like Figure 1As shown in (b), when a new output substation 5a is added during system operation, the output substation 5a is an address-unrecognized substation, but in the output substation 5a that has not received the verification identifier, the control data acquisition mechanism 51 is not activated. Therefore, even if the output substation 5a that is an address-unrecognized substation is accidentally set with an address that overlaps with the address corresponding to the data area assigned to the existing substations 4, 5, and 6, it is possible to prevent the erroneous operation of the device associated with the output substation 5a.

[0069] When the added output slave station 5a is to be operated, after it is added, by executing the processing for identifying the address in a state where the correct address is set, it can transmit and receive data with the main station 2 using the control monitoring data area.

[0070] In addition, when a substation that has been used in another system is transferred, the data transceiver with the main station that can use the control monitoring data area in the previous system may also be able to operate in the system after the transfer. Therefore, it is preferable that the verification identifier is less likely to be set repeatedly in different systems. For example, it is also possible to add the value of the date and time set to the identification number assigned to each system.

[0071]

Explanation of symbols

Claims

1. A control monitoring signal transmission system, comprising: a master station for transmitting and receiving data with a control unit and a plurality of slave stations for transmitting and receiving data with the master station via a common transmission line in a synchronous transmission mode, The data transmission and reception between the master station and the slave station is performed by overlapping the data on the frame repeatedly sent from the master station. The frame is divided into time periods and is provided with a control monitoring data area in which the data transmission direction is determined and allocated to each of the substations, and a management data area which is different from the control monitoring data area and is used for data transmission and reception with all the substations. For each of the slave stations, a numerical value is set in the control monitoring data area as an address for obtaining the data area allocated to the own station. The master station transmits a verification identifier using the management data area at a timing after the process for detecting the address is executed. When the slave station receives the verification identifier, it enables data transmission and reception using the control monitoring data area and records and stores the verification identifier. When the operational identifier is sent from the main station, it enables or disables data transmission and reception using the control monitoring data area based on the verification result of the operational identifier and the verification identifier.

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