JP2002063676A - Terminal connection unit for field bus and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize the know-how of control developed up to the moment without requiring new development costs when replacing a detecting terminal or operating terminal with a terminal for field bus. SOLUTION: In data sent from a detecting terminal 4B, only data corresponding to measured data sent from a detecting terminal 4A for analog signal by an analog signal are converted into data for back plane bus by the signal converting part of a detecting terminal connection unit FBS-AI 14 for field bus. Besides, data transferred from a CPU 10 through a back plane bus 19 are converted into data for field bus corresponding to operation data sent to an operating terminal 6A for analog signal by an analog signal by the signal converting part of an operating terminal connection unit FBS-AO 15 for field bus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field bus terminal connection unit and a controller, and more particularly to a field bus terminal connection unit used when a field bus field terminal is controlled by a controller for controlling an analog signal field terminal. It concerns the controller.

[0002]

2. Description of the Related Art A system for remotely controlling a large number of field terminals (field devices) installed in various parts of a factory or a plant has a higher added value than a conventional analog signal control system using a 4-20 mA analog current loop. A field bus system using a bidirectional digital communication protocol capable of transmitting information bidirectionally is being shifted. As a result, a wide range of advantages can be obtained, such as improvement in reliability, integration with a higher-level management system, reduction in facility costs, wiring costs, and maintenance costs.

FIG. 4 shows a configuration example of a control system for analog signals. The analog signal control system includes a controller 1 for controlling the entire system, a monitoring terminal 2A for analog signals for monitoring signals input and output by the controller, and detecting states of various parts of a plant such as a pressure oscillator and an electromagnetic flow meter and outputting analog signals. Terminal terminal 21 that relays each detection terminal 4A to the controller 1 via the detection terminal 4A to be connected to the controller 1 via the two-wire analog signal transmission path 3A, and operates the state of various parts of the plant based on the input analog signal such as a valve positioner or control valve. Operating terminal 6
A, and a terminal block 22 that relays and connects each operation terminal 6A to the controller 1 via the two-wire analog signal transmission path 5A.

[0004] The controller 1 comprises card-type units 10 to 13 having individual functions, and a backplane bus 19 for exchanging information between these units. By selectively mounting these units as needed, the functions provided by the controller 1 can be provided with flexibility and expandability. Among these units, a control unit (hereinafter referred to as CP)
The U) 10 controls the entire controller 1 and performs process control such as controlling the operation terminal 6A by PID control based on process state information obtained from the detection terminal 4A, for example. Command unit (hereinafter referred to as
COMM) 11 exchanges information and commands relating to process control with the analog signal monitoring terminal 2A.

An analog input unit (hereinafter referred to as AN-AI)
12) connects a detection terminal 4A for analog signals via a two-wire analog signal transmission path 3A and a terminal block 21. Then, the measurement data transmitted as an analog signal from the detection terminal 4A is received and transferred to the CPU 10 via the backplane bus 19. The analog output unit (hereinafter referred to as AN-AO) 13 includes a terminal block 22 and a two-wire analog signal transmission line 5A.
Is connected to the operation terminal 6A for analog signals through. Then, the operation data transferred from the CPU 10 via the backplane bus 19 is transmitted to the operation terminal 6A as an analog signal.

[0006]

In such a control system for analog signals, when a field bus is sequentially introduced, a relatively expensive controller uses a conventional controller.
A procedure is adopted in which detection terminals and operation terminals that are relatively inexpensive and obtain high-value-added information are replaced with those for fieldbus. When a fieldbus detection terminal or an operation terminal is connected to such a conventional controller, a new fieldbus I / F unit is attached to the controller, and the fieldbus detection terminal or the operation terminal is connected. A method of exchanging high value-added information between a terminal or an operation terminal and a CPU via a fieldbus I / F unit is conceivable.

[0007] However, such high value-added information is referred to as CP.
In order to use the U, it is necessary to change the control program itself to be executed by the CPU, and this development cost becomes enormous, and the control know-how cultivated by the conventional controller cannot be easily utilized. there were. The present invention is intended to solve such a problem. Even when the detection terminal and the operation terminal are replaced with those for a field bus, no new development cost is required, and the control know-how cultivated up to now is not required. It is an object of the present invention to provide a fieldbus terminal connection unit and a controller that can make full use of.

[0008]

In order to achieve the above object, a field bus terminal connection unit according to the present invention connects a field bus terminal via a field bus, and connects the field bus terminal to the field bus terminal. A field bus interface unit for receiving the digital signal of the field bus and outputting the data as field bus data; and a signal conversion unit for converting the field bus data to backplane bus data that can be exchanged with the backplane bus. The backplane that can select only the data corresponding to the measurement data transmitted by the analog signal from the analog signal detection terminal from the various fieldbus data output from the fieldbus interface unit, and that can be exchanged with the backplane bus Convert to bus data and control In which was set to provide.

Another fieldbus terminal connection unit according to the present invention includes a signal conversion unit for converting backplane bus data provided by the control means into fieldbus data, and a fieldbus terminal via the fieldbus. And a fieldbus interface for transmitting fieldbus data from the signal converter to the fieldbus terminal as a digital signal.
The backplane bus data from the backplane bus is converted into fieldbus data corresponding to operation data transmitted as an analog signal to an analog signal operation terminal.

The fieldbus interface of the fieldbus terminal connection unit may be individually provided for each of a plurality of fieldbus terminals to be connected. In addition, a field bus external connection unit is further provided,
A fieldbus monitoring terminal for monitoring various data exchanged via the fieldbus may be connected, and a digital signal exchanged via the fieldbus interface unit may be transferred to the fieldbus monitoring terminal. A field bus power supply unit may be further provided to supply power to a field bus terminal connected to the field bus via the field bus.

The controller of the present invention has the same function as these field bus terminal connection units.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an analog signal control system in which a field bus terminal connection unit and a controller according to an embodiment of the present invention are used, and the same or equivalent parts as those in FIG. It is. In the present embodiment, a fieldbus terminal connection unit (fieldbus terminal connection means) for connecting a fieldbus field terminal (hereinafter referred to as a fieldbus terminal) to the controller.
And various kinds of data are exchanged between the CPU (control means) and the fieldbus terminal via the fieldbus terminal connection unit and the backplane bus.

Of the fieldbus terminal connection units, a fieldbus detection terminal connection unit (hereinafter referred to as F
The BS-AI 14 is a card-type unit that is detachably attached to the controller 1. This FBS-
The AI 14 connects the fieldbus detection terminal 4B via the fieldbus 3B and the terminal block 21. Then, various data transmitted as digital signals from the detection terminal 4B are received and converted into data for a backplane bus, and the CPU 1
Transfer to 0.

A field bus operation terminal connection unit (hereinafter referred to as FBS-AO) 15 is a controller 1
It is a card-type unit that is detachably attached to the unit. The FBS-AO is connected to a field bus operation terminal 6 via a field bus 5B and a terminal block 22.
Connect B. Then, the operation data transferred from the CPU 10 via the backplane bus 19 is converted into field bus data, and transmitted to the operation terminal 6B as a digital signal.

Next, the FBS-AI will be described in detail with reference to FIG. FIG. 2 shows a configuration example of the FBS-AI. The FBS-AI 14 has a field bus interface unit (hereinafter, referred to as a field bus I / F unit).
81A, 81B, field bus power supply units 82A, 8
2B, signal converter 83, backplane bus interface (hereinafter referred to as backplane bus I / F)
84 and field bus external connection parts 85A, 85B
Is provided.

The field bus I / F sections 81A and 81B connect a detection terminal 4B for the field bus via the field bus, receive a digital signal compliant with the field bus system standard from the detection terminal 4B, and Output as bus data. The field bus power supply units 82A and 82B supply power to the detection terminal 4B via the field bus. In the signal conversion unit 83, of the various fieldbus data output from the fieldbus I / F units 81A and 81B, measurement data (PV value) transmitted as an analog signal from the analog signal detection terminal.
, That is, only the data used in the conventional controller, is converted into data for the backplane bus that can be exchanged with the backplane bus 19, and output.

At this time, in the signal conversion unit 83, the data for the field bus based on the communication protocol of the field bus system is converted from the conventional data structure and the meaning, such as the frame structure, the bit width and the identification information of the detecting terminal, which are completely different. Is converted to backplane bus data. The signal conversion unit 83 has a management function of managing which field bus I / F units 81A and 81B each detection terminal 4B is connected to.
Field bus data from the / F sections 81A and 81B are converted as corresponding field bus data from the detection terminal 4B.

The backplane bus I / F 84 is connected to the backplane bus 19 and transfers backplane bus data output from the signal converter 83 to the CPU 10 via the backplane bus 19. The fieldbus external connection units 85A and 85B provide a fieldbus I /
The digital signals exchanged with the detection terminal 4B in the F sections 81A and 81B are transferred to the fieldbus monitoring terminal 2B.
The backplane bus I / F unit 84 may include, for example, a latch (register) or the like from which the CPU 10 reads out the backplane bus data written by the signal conversion unit 83 via the backplane bus 19. The field bus I / F units 81A and 81B and the signal conversion unit 83
May be configured in the same chip, in which case the field bus data is internal data.
Further, the backplane bus I / F unit 84 may be configured in the same chip.

Therefore, the measurement data detected by the detection terminal 4B is converted into field bus data and transmitted to the field bus 3B as a digital signal. This digital signal is transmitted to the fieldbus I / F of the FBS-AI14.
The data is received by the units 81A and 81B and output as field bus data. As the field bus data, only the data corresponding to the measurement data transmitted by the analog signal from the analog signal detection terminal 4A, that is, only the data used in the conventional controller is selected by the signal conversion unit 83, The data is converted into backplane bus data that can be exchanged with the backplane bus 19. Then, the backplane bus data is transmitted from the backplane bus I / F unit 84 to the backplane bus 19 and transferred to the CPU 10.

As described above, of the data transmitted from the detection terminal 4B for the field bus, only the data corresponding to the measurement data transmitted by the analog signal from the detection terminal 4A for the analog signal is converted into the data for the backplane bus. Since the data is converted and transferred, when replacing the detection terminal with that for the field bus, a method of converting all the data for the field bus into the data for the backplane bus and processing the data by the CPU as in the related art. In comparison, no new development cost of the control program is required, and the control know-how cultivated up to now can be fully utilized. Therefore, the detection terminal can be easily replaced with a field bus.

The field bus I / F units 81A, 81
1B is provided separately for each fieldbus detection terminal 4B, so that the transmission path used for connection with the conventional analog signal detection terminal 4A is replaced by a field for connecting the fieldbus detection terminal 4B. It can be used as it is as a bus transmission path. This eliminates the need for multi-drop connection of multiple detection terminals and operation terminals, which is usually performed in a fieldbus system, and significantly increases the installation cost for changing transmission lines running in factories and plants. Can be reduced. Further, by providing the fieldbus power supply units 82A and 82B, it is not necessary to separately provide a power supply for the fieldbus detection terminal 4B, and the installation cost can be greatly reduced.

Further, the field bus external connection unit 85
A and 85B are provided, and the field bus I / F units 81A and 81A are provided.
1B and the data exchanged between the fieldbus detection terminal 4B are transferred to the fieldbus monitoring terminal 2B. Therefore, a new development cost of the control program is not required, and the conventional analog signal monitoring terminal 2A is not required. Can monitor high value-added information unique to the field bus that cannot be monitored.

Next, the FBS-AO will be described in detail with reference to FIG. FIG. 3 shows a configuration example of the FBS-AO. This FBS-AO15 has a fieldbus I / F.
Units 91A and 91B, a field bus power supply unit 92A,
92B, signal conversion unit 93, backplane bus I / F unit 94, and field bus external connection units 95A and 95B
Is provided.

The backplane bus I / F section 94 is connected to the backplane bus 19 and the backplane bus 1
9 and receives the data for the backplane bus transferred from the CPU 10 and outputs the data to the signal conversion unit 93. The signal conversion unit 93 converts the backplane bus data from the backplane bus I / F unit 94 into operation data (OU) transmitted as an analog signal to the analog signal operation terminal 6A.
(T value) and converts the data to field bus data and outputs the data. The backplane bus I / F unit 94 may be composed of, for example, a latch (register) for reading backplane bus data written by the CPU 10 via the backplane bus 19 by the signal conversion unit 93.

At this time, in the signal conversion unit 93, the data of the conventional backplane bus is transmitted by a fieldbus system having a completely different data configuration and meaning, such as the frame configuration, bit width, and identification information of the detection terminal. Converted to fieldbus data based on protocol. The signal conversion unit 93 has a management function of managing which field bus I / F units 91A and 91B each operation terminal 6B is connected to. The operation terminal 6B specified by the backplane bus data has a management function. And outputs the converted fieldbus data to the fieldbus I / F units 91A and 91B corresponding to the data.

The field bus I / F units 91A and 91B connect a field bus operation terminal 6B via the field bus, and transmit the field bus data from the signal conversion unit 93 to the field bus to the operation terminal 6B. It is transmitted as a digital signal conforming to the system standard. The field bus power supply units 92A and 92B supply power to the operation terminal 6B via the field bus. The fieldbus external connection units 95A and 95B transfer digital signals exchanged with the operation terminal 6B via the fieldbus I / F units 91A and 91B to the fieldbus monitoring terminal 2B.

Therefore, the data transferred from the CPU 10 via the backplane bus 19 is the FBS-AO
15 of the backplane bus I / F unit 94.
This backplane bus data is transmitted to the signal conversion unit 93.
Is converted into field bus data corresponding to the operation data transmitted as an analog signal to the analog signal operation terminal 6A. And this field bus data is
Digital signals are transmitted from the field bus I / F units 91A and 91B to the field bus 5B and transferred to the operation terminal 6B. These field bus I / F units 91A, 91
B and the signal conversion unit 93 may be configured in the same chip, in which case the field bus data is internal data. Further, the backplane bus I / F unit 94 may be configured in the same chip.

As described above, the data transferred from the CPU 10 via the backplane bus 19 is converted into field bus data corresponding to the operation data transmitted as an analog signal to the analog signal operation terminal 6A, and the operation terminal 6B, when the operation terminal is replaced with a field bus type, all backplane bus data processed by the CPU is converted into field bus data and converted to the operation terminal as in the conventional case. Compared with the transfer method, no new development cost of the control program is required, and the control know-how cultivated up to now can be fully utilized. Therefore, the operation terminal can be easily replaced with a field bus terminal.

The field bus I / F units 91A, 9
1B is provided separately for each fieldbus operation terminal 6B, so that the transmission path used for connection with the conventional analog signal operation terminal 6A is replaced by a field for connecting the fieldbus operation terminal 6B. It can be used as it is as a bus transmission path. This eliminates the need for multi-drop connection of multiple operation terminals and operation terminals normally performed in a field bus system, and significantly increases installation costs for changing transmission lines running in factories and plants. Can be reduced. Further, by providing the fieldbus power supply units 92A and 92B, it is not necessary to separately provide a power supply for the fieldbus operation terminal 6B, and the installation cost can be greatly reduced.

Further, the field bus external connection unit 95
A, 95B are provided, and the field bus I / F units 91A, 9B are provided.
1B and the data exchanged between the fieldbus operating terminal 6B are transferred to the fieldbus monitoring terminal 2B, so that a new development cost of the control program is not required, and the conventional analog signal monitoring terminal 2A is not required. Can monitor high value-added information unique to the field bus that cannot be monitored.

In the above description, FBS-AI14 and FB
The case where the S-AO 15 is detachably mounted on the controller 1 as a card type unit has been described as an example.
As a result, the versatility of the FBS-AI14 and the FBS-AO15 is expanded, and a required number of the controllers can be mounted on a required controller. Note that FBS-AI14 and FBS-AO15
Is not limited to a card type unit. For example, the functions of the FBS-AI14 and the FBS-AO15 may be realized by a circuit configuration in which the controller cannot be detached, and the same operational effects as described above can be obtained. In FIG. 1,
Although the case where the AN-AI 12 and the AN-AO 13 are mounted has been described as an example, these are not required for implementing the present invention.

[0032]

As described above, according to the present invention, only the data corresponding to the measurement data transmitted by the analog signal from the analog signal detection terminal among the data transmitted from the field bus detection terminal is described. The data is converted into data for the backplane bus and transferred. Further, the data transferred from the control means via the backplane bus is converted into field bus data corresponding to the operation data transmitted as an analog signal to the analog signal operation terminal and transferred to the operation terminal. Things. Therefore, when replacing the operation terminal with that for the field bus, a new development cost of the control program is not required, and the control know-how cultivated so far can be fully utilized. Therefore, the operation terminal can be easily replaced with a field bus terminal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a controller according to an embodiment of the present invention.

FIG. 2 is a fieldbus detection terminal connection unit (F
3 is a configuration example of BS-AI).

FIG. 3 is a fieldbus operation terminal connection unit (F
3 is a configuration example of the BS-AO).

FIG. 4 is a block diagram of a conventional controller.

[Explanation of symbols]

1 ... controller, 10 CPU (control means / control unit), 11 ... COMM (command unit), 12 ... AN-
AI (analog input unit), 13 AN-AO (analog output unit), 14 FBS-AI (detection terminal connection unit for fieldbus), 15 FBS-AO
(Fieldbus operation terminal connection unit)
2 ... terminal box, 3A, 5A ... 2-wire analog signal transmission path, 3B, 5B ... field bus, 4A ... detection terminal (for analog signal), 4B ... detection terminal (for field bus), 6A ... operation terminal (analog) Signal), 6B ...
Operation terminal (for fieldbus), 81A, 81B, 91
A, 91B: Fieldbus I / F section, 82A, 82
B, 92A, 92B ... field bus power supply unit, 8
3, 93: signal conversion unit; 84, 94: backplane bus I / F unit; 85A, 85B, 95A, 95B: field bus external connection unit.

Claims (10)

[Claims] At least one of an analog input unit for receiving measurement data transmitted as an analog signal from an analog signal detection terminal and an analog output unit for transmitting operation data to an analog signal operation terminal as an analog signal is detachable. It is mounted on a controller that controls the control target by exchanging various data between these units and control means that executes a control program via a backplane bus. A fieldbus terminal connection unit for connecting a fieldbus terminal, for connecting a fieldbus terminal via a fieldbus, receiving a digital signal from the fieldbus terminal, and outputting it as fieldbus data Fieldbus interface Among the various fieldbus data output from the fieldbus interface unit, select only data corresponding to the measurement data transmitted by the analog signal from the analog signal detection terminal, and exchange with the backplane bus. A signal conversion unit that converts the data into data for the backplane bus and provides the converted data to the control unit. At least one of an analog input unit for receiving measurement data transmitted as an analog signal from an analog signal detection terminal and an analog output unit for transmitting operation data to an analog signal operation terminal as an analog signal is detachable. It is mounted on a controller that controls the control target by exchanging various data between these units and control means that executes a control program via a backplane bus. A fieldbus terminal connection unit for connecting a fieldbus terminal, wherein the backplane bus data provided by the control means corresponds to operation data transmitted as an analog signal to the analog signal operation terminal. A signal converter for converting to fieldbus data A fieldbus terminal for connecting a fieldbus terminal via a fieldbus and transmitting fieldbus data from the signal converter to the fieldbus terminal as a digital signal to the fieldbus terminal. Connection unit. 3. The fieldbus terminal connection unit according to claim 1, wherein the fieldbus interface unit is individually provided for each of a plurality of fieldbus terminals to be connected. Terminal connection unit. 4. The field bus terminal connection unit according to claim 1, wherein a field bus monitoring terminal for monitoring various data exchanged on the field bus is connected, and a digital signal exchanged on the field bus interface unit. A fieldbus terminal connection unit, further comprising: a fieldbus external connection unit for transferring the fieldbus to the fieldbus monitoring terminal. 5. The field bus terminal connection unit according to claim 1, further comprising: a field bus power supply unit that supplies power to the field bus terminal connected to the field bus via the field bus. A terminal connection unit for a field bus, comprising: 6. An analog input unit for receiving measurement data transmitted as an analog signal from an analog signal detection terminal, and an analog output unit for transmitting operation data to an analog signal operation terminal as an analog signal. A controller that is freely mounted and controls a control target by exchanging various data between these units and a control unit that executes a control program via a backplane bus, and a fieldbus terminal is connected to the controller. A fieldbus terminal connection means for connecting the fieldbus terminal via the fieldbus, receiving a digital signal from the fieldbus terminal, and transmitting the signal as fieldbus data. Output fieldbus interface Source section, from among various fieldbus data output from the fieldbus interface section, selects only data corresponding to measurement data transmitted as analog signals from the analog signal detection terminal, and selects the backplane bus A signal conversion unit that converts the data into data for backplane bus that can be exchanged with the control unit and provides the data to the control unit. 7. At least one of an analog input unit for receiving measurement data sent as an analog signal from an analog signal detection terminal and an analog output unit for sending operation data to an analog signal operation terminal as an analog signal is detachable. A controller that is freely mounted and controls a control target by exchanging various data between these units and a control unit that executes a control program via a backplane bus, and a fieldbus terminal is connected to the controller. The fieldbus terminal connection means for connecting the backplane bus data provided by the control means to the analog signal operation terminal in the form of an analog signal. To convert to fieldbus data corresponding to And a fieldbus interface unit for connecting a fieldbus terminal via a fieldbus and transmitting the fieldbus data from the signal conversion unit as a digital signal to the fieldbus terminal. Controller. 8. The controller according to claim 6, wherein the fieldbus interface unit is individually provided for each of a plurality of fieldbus terminals to be connected. 9. The controller according to claim 6, wherein said fieldbus terminal connection means connects a fieldbus monitoring terminal for monitoring various data exchanged via said fieldbus, and said fieldbus interface unit. A controller further comprising a fieldbus external connection unit for transferring an exchanged digital signal to the fieldbus monitoring terminal. 10. The fieldbus power supply according to claim 6, wherein the fieldbus terminal connection means supplies power to a fieldbus terminal connected to the fieldbus via the fieldbus. A controller further comprising a supply unit.