JP2003084810A - Distributed control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a distributed control system capable of monitoring the operation even at a place where a control bus can not be installed, such an engineer's desk and a place near a plant site. SOLUTION: In this distributed control system wherein an operation monitoring station and a control station are connected to a control bus, a radio communication device is mounted another control bus used when the operation monitoring system communicates to an upper tier. A radio operation control device communicates to the control station while applying the radio communication device as an access point, to operate and monitor the plant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed control system in which an operation monitoring station and a control station are connected to a control bus and communication is performed between these stations to control a plant.

[0002]

2. Description of the Related Art A distributed control system is used as a system for controlling and operating a plant by controlling process amounts such as temperature and pressure existing in the plant. The distributed control system has a configuration in which an operation monitoring station and a control station are connected to a control bus, the control station is responsible for controlling the plant, and the operation monitoring station is responsible for operating and monitoring the plant. A plurality of control stations are distributed and arranged in the plant according to the scale of the plant to be controlled.

FIG. 2 is a diagram showing a configuration example of a conventional distributed control system. In FIG. 2, the operation monitoring stations 10 and 11 and the control station 12 are connected to the control bus 13. The control station 12 is the plant 14
Control. The control station 12 inputs / outputs various signals such as an analog signal of 4 to 20 mA, 1 to 5 V, a thermocouple signal, and a contact signal with the plant 14 via an input / output unit (not shown). To do. Although only one control station 12 is shown in the figure, the control stations 12 are distributed in the plant.

The operation monitoring stations 10 and 11 communicate with the control station 12 via the control bus 12 to perform operation and monitoring of the plant. Operation monitoring station 1
Reference numerals 0 and 11 are provided with a display device having a man-machine interface function, and various screens or windows required for controlling and monitoring the plant are displayed on this display device. The operation monitoring stations 10 and 11 have different configurations. For example, the operation monitoring station 10 is an operation monitoring station having an engineering function of constructing a system.

The operation monitoring stations 10 and 11 are also connected to the control bus 15. The control bus 13 is, for example, a communication bus unique to the system. On the other hand, the control bus 15 is a general-purpose communication bus. The control bus 15 is, for example, an Ethernet (registered trademark) bus. For example, the control bus 13 is used as a control system network, and the control bus 1
5 is used as an information network. The operation monitoring stations 10 and 11 communicate with the servers in the upper hierarchy via the control bus 15.

In the conventional example of FIG. 2, the operation monitoring stations 10 and 11 are realized by installing an operation monitoring program in a personal computer on the control bus 13. The operation monitoring stations 10 and 11 had to be connected to the control bus 13 in order to read and write data from the control station 12. Therefore, it is necessary to lay a control bus to install the operation monitoring station. For this reason, operation monitoring can be performed only in the central monitoring room or in a limited place, and a person in charge at the plant site sometimes exchanges information with the operator in the central monitoring room using a transceiver.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by providing an operation and monitoring device for performing wireless communication, it is possible to use it in a place near an engineer's desk or a plant site. It is an object of the present invention to realize a distributed control system capable of performing operation monitoring even in a place where a special control bus cannot be installed.

[0008]

The present invention is a distributed control system having the following configuration.

(1) The operation monitoring station and the control station are connected to a control bus, and the control stations are distributed in the plant and are in charge of controlling the plant.
The operation monitoring station is a distributed control system that is in charge of operation and monitoring of a plant. In the distributed control system, another operation bus used when the operation monitoring station communicates with an upper layer, A relay device that relays communication, a wireless communication device connected to the other control bus, and wireless communication with the wireless communication device, and passes through the wireless communication device, another control bus, the relay device, and the control bus. And a wireless operation monitoring device that communicates with the control station to perform operation and monitoring of the plant.

(2) The distributed control device according to (1), wherein the wireless communication device is provided at a plurality of points on another control bus.

(3) The distributed control device according to (1), wherein the other control bus is a general-purpose communication bus.

(4) The distributed control device according to (1), wherein the relay device is a gateway.

(5) The distributed control device according to (1), wherein the wireless operation monitoring device is a portable personal computer having a wireless communication function.

(6) The operation monitoring station and the control station are connected to a control bus, and the control stations are distributed in the plant and are in charge of controlling the plant.
The operation monitoring station, in a distributed control system that is in charge of operation and monitoring of a plant, performs wireless communication with the wireless communication device connected to the control bus, and the wireless communication device and the control bus. A distributed control device comprising: a wireless operation monitoring device that communicates with the control station via the wireless operation monitoring device to perform operation and monitoring of the plant.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the same parts as those in the previous figure are designated by the same reference numerals.
In FIG. 1, the relay device 20 relays communication between the control buses 13 and 15. When relaying communication from the control bus 13 to the control bus 15, the relay device 20 converts the communication packet of the control bus 13 into the communication packet of the control bus 15.
When relaying communication from the control bus 15 to the control bus 13, the reverse conversion is performed. Such a relay device 20 is realized by, for example, a gateway.

The wireless communication device 21 is connected to the control bus 15. The wireless communication device 21 may be provided at a plurality of points on the control bus 15. The installation point of the wireless communication device 21 is a wireless LAN (Local Area Network).
k) access point. Wireless operation monitoring device 22
Has an operation monitoring function and performs wireless communication with the wireless communication device 21 on the control bus 15. As a result, the wireless operation monitoring device 22 is connected to the wireless communication device 21 via the wireless LAN. This wireless LAN complies with the IEEE 802.11b standard, for example. The wireless operation monitoring device 22 communicates with the control station 12 via the wireless communication device 21, the control bus 15, the relay device 20, and the control bus 13 to perform operation and monitoring of the plant. The wireless operation monitoring device 22 is, for example, L
It is realized by a portable personal computer having a wireless communication function such as an AN adapter.

In the system of FIG. 1, the wireless operation monitoring device 2
The wireless communication device 2 communicates with the control station 12 by performing wireless communication with the wireless communication device 21 and further performing wired communication with the control bus 15, the relay device 20, and the control bus 13. As a result, the operation and monitoring of the plant are performed. Therefore, the wireless operation monitoring device 22 can perform operation monitoring even in a place where the control bus 15 is not installed, as long as it is an area where communication with the wireless communication device 21 is possible.

In the embodiment, the case where the wireless communication device 21 is installed on the control bus 15 has been described, but the wireless communication device 21 may be installed on the control bus 13. In this case, the relay device 20 becomes unnecessary.

[0019]

According to the present invention, the following effects can be obtained.

According to the present invention, the wireless communication device is installed on the control bus to provide the access point, and the wireless operation monitoring device communicates with the control station via the access point. Operates and monitors the plant. As a result, operation monitoring can be performed even in a place where a control bus cannot be laid, such as a place near an engineer's desk or a plant site.

According to the second aspect of the present invention, since the wireless communication device is provided at a plurality of points on the control bus, it is possible to perform operation monitoring at various places on the plant site. In addition, the worker can carry out operation monitoring while moving on site with the wireless operation monitoring device.

According to the third aspect of the invention, since the control bus is a general-purpose communication bus, a wireless access point can be easily provided.

According to the fifth aspect of the invention, since the wireless operation monitoring device is a portable personal computer, an operator can carry an operation monitor while carrying a notebook personal computer that is portable and not connected.

In the invention according to claim 6, since the wireless access point is provided on the control bus to which the control station is connected, the relay device is not required.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a conventional distributed control system.

[Explanation of symbols]

10, 11 Operation monitoring station 12 Control station 13,15 control bus 14 plants 20 Relay device 21 wireless communication device 22 Wireless operation monitoring device

Claims (6)

[Claims] 1. An operation monitoring station and a control station are connected to a control bus, the control station is distributed in the plant and is in charge of controlling the plant, and the operation monitoring station is in charge of operation and monitoring of the plant. In the distributed control system, another control bus used when the operation monitoring station communicates with an upper layer, a relay device that relays communication between the control bus and another control bus, and the other control bus Performs wireless communication with the wireless communication device connected above, communicates with the control station via the wireless communication device, another control bus, a relay device, and a control bus, and operates the plant. And a wireless operation monitoring device for monitoring the distributed control device. 2. The distributed control device according to claim 1, wherein the wireless communication device is provided at a plurality of points on another control bus. 3. The distributed control device according to claim 1, wherein the other control bus is a general-purpose communication bus. 4. The distributed control device according to claim 1, wherein the relay device is a gateway. 5. The distributed control device according to claim 1, wherein the wireless operation monitoring device is a portable personal computer having a wireless communication function. 6. An operation monitoring station and a control station are connected to a control bus, the control stations are distributed in the plant and are in charge of controlling the plant, and the operation monitoring station is in charge of operation and monitoring of the plant. In a distributed control system, a wireless communication device connected on the control bus, wirelessly communicates with the wireless communication device, communicates with the control station via the wireless communication device and the control bus, and operates a plant. A distributed control device comprising: a wireless operation monitoring device for performing operation and monitoring.