Automation field equipment

Abstract

The present invention relates to an automation field device (F), comprising: at least four connection pins (1, 2, 3, 4) for connecting a field device (17); and a field device electronic device unit (16), which is designed to provide a 4-20mA signal via the first and second connection pins (1, 2) in a first operating state, is supplied with a power supply voltage via the first and third connection pins (1, 3) in a second operating state, and implements IO link communication via the fourth connection pin (4) or provides a first switch output (Q1) and additionally provides a second switch output (Q2) at the second connection pin (2), and in a third operating state is supplied with a power supply voltage via the first and third connection pins (1, 3), and implements IO link communication via the fourth connection pin (4) or provides a first switch output (Q1) and additionally provides a 4-20mA power output at the second connection pin (2), the field device electronic device unit (16) is also designed to be configured so that it can selectively operate in one of the three operating states.

Description

Technical Field

[0001] The invention relates to an automated field device. Background Art

[0002] In automation technology, especially in process automation technology, field devices are often used, which are used to record and / or influence process variables. For recording process variables, sensors, such as level measuring devices, flow measuring devices, pressure and temperature measuring devices, pH-redox potential measuring devices, conductivity measuring devices, etc., are used, which record the corresponding process variables, level, flow, pressure, temperature, pH value and conductivity. For influencing process variables, actuators (such as valves or pumps) can be used to change the flow of liquid in a pipeline section or the level in a container. In principle, what are called field devices are all devices that are used near the process and transmit or process process-related information. Therefore, the term field device related to the present invention also particularly relates to remote I / O, radio adapters and devices that are usually arranged at the field level.

[0003] A large number of such field devices are produced and sold by the company Endress+Hauser.

[0004] For historical reasons, these are usually connected to a superordinated unit, such as a controller (PLC) or a control system, via a two-conductor line (i.e. a line with two separately formed leads). In this case, the two-conductor field device is implemented so that the measured value or actuation value as a process variable is communicated, i.e. sent, via the two-conductor line or a two-conductor cable in analog form as a 4-20 mA loop current, thus as a current signal. In this case, the loop current of the two-conductor line is set by the field device and the superordinated unit at a specific value corresponding to the recorded process variable.

[0005] In addition, the field device can also be supplied with energy via a two-conductor line. However, in this case, only very limited energy is available for the field device. Alternatively, in the case where more energy is required than can be supplied to the field device via a two-conductor line, the field device can also be connected via a three-wire or four-wire line. This may be necessary, for example, when measurements must be made more frequently. In the case of a three-wire or four-wire line, the energy is transmitted on a separate line pair, and the measured value or actuation value is transmitted on the third line in the form of a 4-20mA signal.

[0006] In addition to the "traditional" connection of field devices via two-conductor lines, in cases where measured values ​​or actuation values ​​are transmitted via 4-20 mA signals, more and more new transmission / communication devices are used. One of these systems is the IO-Link. The IO-Link is a communication device for connecting smart sensors and actuators, which is based on the IEC 61131-9 standard of September 2013 entitled "Single-drop digital communication interface for small sensors and actuators" (SDCI).

[0007] Typically, field device manufacturers produce field devices for 4-20mA signals or IO-linked operation. That is, the field device electronics located in the field device unit are given hardware for 4-20mA operation or IO-linked operation. In addition, the field device electronics hardware can achieve two-wire, three-wire or four-wire operation. This means that special field device electronics must be manufactured for virtually every combination of operating states or operating characteristics. Summary of the invention

[0008] It is therefore an object of the present invention to provide a field device with field device electronics which is based on a “one design fits all” concept and which can thus be flexibly set to desired operating states.

[0009] According to the invention, this object is achieved by an automation field device.

[0010] The automation field device of the present invention comprises:

[0011] - At least four connection pins for connecting field devices;

[0012] - Field device electronics, which is suitable for: in a first operating state, providing a 4-20mA signal via the first and second connection pins; in a second operating state, being supplied with a supply voltage via the first and third connection pins, and enabling IO link communication via the fourth connection pin or providing a first switch output and supplementarily providing a second switch output on the second connection pin; and in a third operating state, being supplied with a supply voltage via the first and third connection pins, and enabling IO link communication via the fourth connection pin or providing the first switch output and supplementarily providing a 4-20mA current output on the second connection pin, wherein the field device electronics is also suitable for being configured so as to be able to selectively operate in one of the three operating states.

[0013] An advantageous embodiment of the field device of the present invention provides that the field device electronics is further adapted to automatically detect whether the IO link communication occurs or should occur via the fourth connection pin or whether the fourth connection pin is used as the first switch output. In particular, this embodiment can provide that the automatic detection occurs depending on the device connected to the fourth connection pin.

[0014] A further advantageous embodiment of the field device of the invention provides that in a first operating state, in which the 4-20 mA signal is provided via the first and second connecting pins, the third and fourth connecting pins are deactivated.

[0015] Another advantageous embodiment of the field device of the present invention provides that the field device electronics is configured via a fourth connection pin enabling the IO link communication to correspond to one of the three operating states. In particular, embodiments can provide that the configuration occurs before the start-up of the field device in the automation plant, in particular in or during the assembly of the field device.

[0016] A further advantageous embodiment of the field device of the invention provides that, for operating the field device electronics in the third operating state, an external load resistor is connected between the second connecting pin and the third connecting pin. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will now be explained in more detail based on the accompanying drawings, which show the following:

[0018] Figure 1 is a block diagram of a field device of the invention having field device electronics adapted to operate in a first operating state,

[0019] Figure 2 is a block diagram of a field device of the present invention having field device electronics adapted to operate in a second operating state, and

[0020] Figure 3 is a block diagram of a field device of the present invention having field device electronics adapted to operate in a third operating state. DETAILED DESCRIPTION

[0021] Figures 1 to 3Each shows a field device 17 which, in terms of hardware, has a uniformly, identically formed field device electronics 16. The identically implemented field device electronics comprise in each case: four connection pins 1, 2, 3, 4, via which the field device 17 can be connected to the automation plant, an EMC filter 5, downstream of the connection pins 1, 2, 3, 4, for protecting the field device 17 from possible EMC interferences, an electronics power supply unit 6 for internal energy supply, a microprocessor 7 for internal control of the field device electronics 16, a sensor or actuator element 8 for recording or setting measured values ​​or actuation values, as the case may be, a load resistor 9 and a 4-20 mA current regulator 10, which sets the current value I together with the load resistor 9. Furthermore, the field device electronics 16 comprises an auxiliary circuit 12 for implementing an IO-link operation, which is used to form a first and a second auxiliary path 12a, 12b, and an IO-link unit 13 for implementing an IO-link communication. In this case, the IO link unit 13 is connected to the first output path 13a via the EMC filter using the fourth connection pin 4, so that a bidirectional IO link communication can occur via the fourth connection pin 4. Moreover, the IO link unit 13 is connected to the power supply path 13b via the EMC filter 5 using the third connection pin 3, and is connected to the power supply path 13c using the first connection pin 1 via the EMC filter. The IO link unit 13 is supplementarily connected to the second connection pin 2 via the switch unit 14 and the EMC filter 5. The switch unit 14 is implemented in a manner that the second connection pin 2 can be operated as a second switch output Q2 or as a current output (active or passive in dual-conductor operation), and a 4-20mA signal is output on the current output. For example, the configuration of the switch unit 14 can occur by means of a microprocessor. This can, for example, operate an auxiliary circuit via a control signal, which forwards the control signal to the switch unit.

[0022] Additionally or alternatively, configuration may take place via IO-link communication, for example by means of an IO-link master connected to the fourth connection pin 4. This may take place, for example, at or during assembly of the field device 17 by the field device manufacturer.

[0023] In order to be able to control the IO-link unit 13 and the auxiliary circuit 12, the microprocessor is connected to the IO-link unit 13 via the first and second control lines 7a and 7b and to the auxiliary circuit 12 via the third control line 7c. In order to be able to coordinate possible voltage level differences between the microprocessor 7 and the IO-link unit 13, a first level converter 15a can be introduced into the first control line 7a and a second level converter 15b into the second control line 7b.

[0024] Furthermore, the field device electronics can comprise a display, for example in the form of a touch display, and / or an input unit 11. Via the display and / or input unit 11, for example, measured values ​​or actuation values ​​can be displayed or a parameterization of the field device 17 can be performed.

[0025] Due to the identically implemented field device electronics 16 , according to the invention, this can be operated in different operating states. Figures 1 to 3 Different operating states are shown, wherein for the sake of clarity in each case inactive electrical connections are shown with dashed lines, electrical connections for data transmission are shown with thin lines, electrical connections for energy transmission are shown with medium lines, and electrical connections for energy transmission and data transmission are shown with thick lines.

[0026] First, the field device electronics 16 may be such as Figure 1 The device is shown operating in a first operating state, which is a pure 4-20mA two-wire operation. In this case, the two-conductor line is connected to the first and second connection pins 1 and 2 in order to apply a voltage to the field device electronics 16. The current I is fed to the electronics power supply unit 6 via the EMC filter 5 on a first data and / or energy supply path or 4-20mA path 6a, which in the first operating state represents a 4-20mA input path (in Figure 1 In the first operating state, on the one hand, the supplied current I feeds the electronics power supply unit 6 so that it can provide an internal operating voltage, and on the other hand, the current I provides a signal in the form of a 4-20 mA signal, via which a measured value or an actuation value can be transmitted. For example, when the field device is embodied as a sensor, i.e. has a sensor element, the current can be set via a 4-20 mA current regulator 10 together with a load resistor 9 corresponding to the process variable recorded by the sensor element, in order to be subsequently transmitted to a superordinate unit ( Figure 1 In order to enable pure 4-20 mA two-wire operation, the switch unit 14 is configured such that the current I from the load resistor 9 is directed to the second connection pin 2 via the 4-20 mA output path 9 a.

[0027] Additionally, the field device electronics 16 may include, for example, Figure 2 The IO-link unit 13 and the electronics power supply unit 6 are in this case supplied with energy via the first data and / or energy supply path or the 4-20 mA path 6 a, which in the second operating state represents a pure energy supply path (in Figure 2 medium is indicated by a line with medium thickness).

[0028] In addition, in the second operating state, via the fourth connection pin 4, IO link communication is realized, or the first switch output Q1 is provided alternatively. In addition, in the second operating state, a second switch output Q2 is provided on the second connection pin 2. To this end, the switch unit 14 switches between the 4-20mA output path and the third output path 13d. In the second operating state, the field device electronics 16 is supplied via an internal supply auxiliary path, which can be guided by a reference diode 12c. However, for this purpose, a higher supply voltage of about 10V is required. The reference diode 12c can be part of the auxiliary circuit 12. The supply auxiliary path includes a third control line 7c, a second auxiliary path 12b and an eighth auxiliary path 9b.

[0029] Furthermore, the field device electronics 16 may also be adapted to automatically detect whether an IO-link communication with an external IO-link master device should occur via the fourth connection pin 4 or whether the fourth connection pin should be used as the first switching output Q1. For the automatic detection, the field device electronics 16 may, for example, be adapted to monitor whether the fourth connection pin 4 is quickly pulled to an inverting switching state by the external IO-link master device.

[0030] Additionally, the field device electronics 16 may include, for example, Figure 3 3. The field device electronics 16 is shown to be operated in the third operating state. In the third operating state, the supply voltage is again supplied to the field device electronics 16 via the first and third connection pins 1, 3. Also in the third operating state, via the fourth connection pin 4, an IO link communication is realized or a first switching output Q1 is provided. In addition, a 4-20mA current output is provided on the second connection pin 2. In the third operating state, an external (field device external) load resistor 18 can be connected between the connection pin 3 and the connection pin 2. In this case, energy is supplied to the field device electronics via the 4-20mA current I fed on the first connection pin 1.

[0031] If no external load resistor 18 is connected between the connection pins 2 and 3 , in the third operating state, the field device electronics 16 are supplied with energy via the internal supply auxiliary path exactly as in the second operating state.

[0032] Reference Mark List

[0033] 1First connection pin

[0034] 2 Second connection pin

[0035] 3 Third connection pin

[0036] 4Fourth connection pin

[0037] 5EMC filter

[0038] 6Electronic equipment power supply unit

[0039] 6a First data and / or energy supply path / 4-20mA path

[0040] 7. Microprocessor

[0041] 7a First control line

[0042] 7b Second control line

[0043] 7c Third control line

[0044] 8 Sensor or actuator elements

[0045] 9 Load resistance

[0046] 9a 4-20mA output path

[0047] 9b Eighth Auxiliary Path

[0048] 10 4-20mA current regulator

[0049] 11Display and / or output unit

[0050] 12 Auxiliary circuit

[0051] 12a First auxiliary path

[0052] 12b Second auxiliary path

[0053] 12c Reference diode

[0054] 13 IO Link Unit

[0055] 13a to the first output path connected to pin 4

[0056] 13b to the second output path connected to pin 3

[0057] 13c Supply Path

[0058] 13d to the third output path connected to pin 2

[0059] 14 switch units

[0060] 15a First level converter between IO link unit and microprocessor

[0061] 15b Second level converter between microprocessor and IO link unit

[0062] 16 Field device electronics

[0063] 17 Field Equipment

[0064] 18 External load resistor

[0065] I Current

[0066] Q1 First switch output

[0067] Q2 Second switch output

Claims

1. An automated field device, comprising: - at least four connection pins for connecting a field device (17); - Field device electronics (16), adapted to: in a first operating state, provide a 4-20 mA signal via a first connection pin (1) and a second connection pin (2); in a second operating state, be supplied with a supply voltage via the first connection pin (1) and the third connection pin (3), and enable IO link communication via the fourth connection pin (4) or provide a first switch output (Q1) and supplementarily provide a second switch output (Q2) on the second connection pin (2); and in a third operating state, be supplied with a supply voltage via the first connection pin (1) and the third connection pin (3), and enable IO link communication via the fourth connection pin (4) or provide the first switch output (Q1) and supplementarily provide a 4-20 mA current output on the second connection pin (2), wherein the field device electronics (16) is further adapted to be configured so as to be able to selectively operate in one of the three operating states.

2. The automation field device according to claim 1, wherein: The field device electronics (16) are further adapted to automatically detect whether the IO link communication occurs or should occur via the fourth connection pin (4) or whether the fourth connection pin (4) is used as the first switching output (Q1).

3. The automation field device according to claim 2, wherein: Automatic detection occurs depending on the device connected to the fourth connection pin (4).

4. The automation field device according to any one of claims 1 to 3, wherein: In a first operating state in which the 4-20 mA signal is provided via the first connection pin (1) and the second connection pin (2), the third connection pin (3) and the fourth connection pin (4) are deactivated.

5. The automation field device according to any one of claims 1 to 3, wherein: The field device electronics (16) are adapted to be configured corresponding to one of the three operating states via a fourth connection pin (4) enabling the IO link communication.

6. The automation field device according to claim 5, wherein: Configuration takes place prior to startup of the field devices (17) in the automated plant.

7. The automation field device according to claim 6, wherein: Configuration takes place during assembly of the field device.

8. The automation field device according to any one of claims 1 to 3, wherein: In order to operate the field device electronics in the third operating state, an external load resistor (18) is connected between the second connecting pin (2) and the third connecting pin (3).

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