Field device

Abstract

The invention relates to a field device for connection to a programmable logic controller having hardware comprising a processing unit, a memory and a data interface for communication with the programmable logic controller. The field device is characterized in that it is configured to receive compatibility information from the programmable logic controller by means of the data interface, wherein a firmware having a plurality of functions for operating the field instrument is stored in the memory, wherein the processing unit is configured to release a subset of the functions of the firmware for execution in dependence on the compatibility information to produce a behavior of the field device which is adapted to the compatibility information of the programmable logic controller.

Claims

1. A field device for connection to a programmable logic controller (PLC), the field device having hardware, and the hardware comprising: a processing circuitry, a memory, and a data interface for communication with the PLC, wherein the field device is configured to receive compatibility information from the PLC; wherein a firmware having a plurality of functions for operating the field device is stored in the memory; and wherein the field device determines which functions of the firmware of the field device are known to the PLC using the compatibility information and the processing circuitry is configured to release only a subset of the functions of the firmware that is known to the PLC for execution during an operation of the field device without booting based on checking the received compatibility information one-by-one against a predetermined association of each of the plurality of the functions and a firmware version number or date that allows release of the function respectively, and preclude functions, other than the subset of the functions, that currently reside on the field device from execution, based on the compatibility information to produce a behavior of the field device which is configured to adapt to the compatibility information and adopt a function and behavior of the field device with an older version of the firmware to conform to the current programming of the PLC, when the compatibility information does not require all of the functions of the firmware, and wherein the processing circuitry is configured, if none of the plurality of functions is suitable to produce the behavior of the field device configured to adapt to the compatibility information, to download a further firmware and to continue the operation of the field device with the further firmware by releasing further functions of the further firmware for execution simultaneously.

2. The field device in accordance with claim 1, wherein the field device is an actuator control.

3. The field device in accordance with claim 1, wherein the processing circuitry is configured to select the subset of the released functions such that the subset of the released functions can be controlled and used by means of the PLC.

4. The field device in accordance with claim 1, wherein the processing circuitry is configured to select the subset of the functions released for execution during the operation of the field device.

5. The field device in accordance with claim 1, wherein the compatibility information includes version information on the PLC.

6. The field device in accordance with claim 1, wherein the compatibility information includes a desired version of the field device.

7. The field device in accordance with claim 1, wherein all of the plurality of functions of the firmware use the same firmware kernel.

8. The field device in accordance with claim 1, wherein all of the plurality of functions of the firmware have a hardware abstraction layer and all of the plurality of functions of the firmware use the same hardware abstraction layer.

9. The field device in accordance with claim 1, wherein at least one of a version number and a date is associated with at least one function of the plurality of functions of the firmware.

10. The field device in accordance with claim 1, wherein the processing circuitry is configured to release the subset of the functions by means of at least one of a conditional request and a selection of an inheritance.

11. The field device in accordance claim 1, wherein the further firmware only comprises further functions configured to adapt to the hardware of the field device.

12. The field device in accordance with claim 1, wherein the further firmware comprises a firmware kernel differing from at least one of the firmware and a different hardware abstraction layer.

13. A method of connecting a field device to a programmable logic controller (PLC), wherein the field device comprises a firmware having a plurality of functions, in which the method comprising: receiving, by the field device, compatibility information from the PLC by means of a data interface; and determining which functions of the firmware of the field device are known to the PLC using the compatibility information and releasing only a subset of the functions of the firmware that is known to the PLC for execution during an operation of the field device without booting. based on checking the received compatibility information one-by-one against a predetermined association of each of the plurality of the functions and a firmware version number or date that allows release of the function respectively, and precluding functions, other than the subset of the functions, that currently reside on the field device from execution, based on the compatibility information to produce a behavior of the field device which is configured to adapt to the compatibility information and adopt a function and behavior of the field device with an older version of the firmware to conform to the current programming of the PLC, when the compatibility information does not require all of the functions of the firmware, and if none of the plurality of functions is suitable to produce the behavior of the field device configured to adapt to the compatibility information, to download a further firmware and to continue the operation of the field device with the further firmware by releasing further functions of the further firmware for execution simultaneously.

Description

(1) The invention will be described in the following purely by way of example with reference to the enclosed drawings. There are shown:

(2) FIG. 1 the schematic structure of a field device in accordance with the invention; and

(3) FIG. 2 a programmable logic controller with a plurality of connected field devices in accordance with the invention.

(4) FIG. 1 shows a field device 10 which is configured as a motor control (a so-called drive). The field device 10 has hardware 12 which comprises a processing unit

(5) The compatibility firmware 14 enables an electric motor (not shown) connected to the field device 10 to be operated. The field device 10 receives control commands by means of a data interface (likewise not shown) for operating the electric motor.

(6) The compatibility firmware 14 comprises a hardware abstraction layer 16 which is adapted to the hardware 12. The compatibility firmware 14 furthermore comprises a kernel 18 which provides a basic functionality.

(7) An advanced functionality of the compatibility firmware 14 is provided by a plurality of functions, with a first function 20, a second function 22, a third function 24 and a fourth function 26 being shown by way of examples in the Figures. The functions 20, 22, 24, 26 can serve, for example, to control complex movement processes of the electric motor in a simple manner.

(8) The four functions 20, 22, 24, 26 allow the formation of a maximum of 15 subsets. The field device 10 can consequently map 15 different behaviors.

(9) The third function 24 and the fourth function 26 were taken over from a field device which represents a predecessor of the shown field device 10 and whose hardware was less powerful than the shown hardware 12. The first function 20 and the second function 22 require the more powerful hardware 12 of the shown version of the field device 10.

(10) Instead of the compatibility firmware 14, performance firmware 15 can also be loaded into the field device 10 by means of a bootloader (not shown) and can replace the compatibility firmware 14. The performance firmware 15 utilizes the hardware 12 ideally with respect to timing and real time capability.

(11) The performance firmware 15 comprises an alternative hardware abstraction layer 17 and an alternative kernel 19. In addition, the performance firmware 15 comprises an alternative first function 21, an alternative second function 23, an alternative third function 25 and an alternative fifth function 27. The alternative functions 21, 23, 25, 27 are released for execution together.

(12) FIG. 2 shows four field devices which are connected to a programmable logic control (PLC) 30 by means of a data link 28, e.g. by means of a fieldbus. The PLC 30 has PLC firmware 32 which is current PLC firmware 32. This means that the PLC firmware 32 is able to use the first, second, third and fourth functions 20, 22, 24, 26 as well as the alternative first, second, third and fourth functions 21, 23, 25, 27. The PLC 30 and the field devices form a system 33.

(13) The field devices connected to the PLC 30 are a field device 10a, a field device 10b and a field device 10c which each have the same hardware 12 as the field device 10 shown in FIG. 1. A further field device 34 has older and less powerful hardware with respect to the field device 10 of FIG. 1.

(14) The field devices 10, 10a, 10b, 34 comprise the same kernel 18 and the same functions 20, 22, 24, 26. The field device 10c comprises the performance firmware 15. The further field device 34 has a modified hardware abstraction layer 16 in comparison with the field devices 10, 10a, 10b due to its different hardware.

(15) Those functions 20, 22, 24, 26 which are released for execution are shown filled black in FIG. 2. That is, the first, second and third functions 20, 22, 24 are released in the field device 10a. Only the respective third function 24 and the fourth function 26 are released in the field device 10b as well as in the further field device 34.

(16) Such a release can, for example, be achieved in that the PLC 30 transmits compatibility information to the field device 10a which instruct the field device 10a to provide the latest functions 20, 22, 24.

(17) The field device 10b and the further field device 34 have, in contrast, been instructed to provide that functionality which can be executed with the hardware of the further field device 34. Only the third and fourth functions 24, 26 are accordingly executed on the field device 10b and on the further field device 34.

(18) The field device 10c can in this manner replace a field device which corresponds to the further field device 34 since the functionality of the field device 10b can correspond to such a field device. The behavior of a further field device 34 can be imitated by the field device 10b in this manner, for which purpose the field device 10b can be operated in a so-called compatibility mode. After such a replacement of an older field device, the field device 10b can advantageously seamlessly take over the function and the behavior of the older field device without modifications to the programming of the PLC 30. An interaction of a user is not necessary for this purpose; the PLC 30 likewise does not have to distinguish between newer field devices (the field devices 10a, 10b) and older field devices (the further field device 34).

(19) The field device 10c has been instructed by the PLC 30 to download the performance firmware 15 by means of the data link 28 from a data store (not shown) and to use it. The field device 20c can utilize a maximum performance from the hardware 12 using the performance firmware 15.

REFERENCE NUMERAL LIST

(20) 10, 10a, 10b, 10c field device

(21) 12 hardware

(22) 14 compatibility firmware

(23) 15 performance firmware

(24) 16 hardware abstraction layer

(25) 17 alternative hardware abstraction layer

(26) 18 kernel

(27) 19 alternative kernel

(28) 20 first function

(29) 21 alternative first function

(30) 22 second function

(31) 23 alternative second function

(32) 24 third function

(33) 25 alternative third function

(34) 26 fourth function

(35) 27 alternative fourth function

(36) 28 data link

(37) 30 PLC

(38) 32 PLC firmware

(39) 33 system

(40) 34 further field device