JP4823093B2 - Digital control system and operation method thereof - Google Patents

Description

  The present invention relates to a digital control system that controls a large-scale plant or the like and can shorten an update period when the apparatus is partially updated, and an operation method thereof.

  In a large-scale plant control system, recently, a digital controller and an optical multiplex transmission apparatus have been applied, and a plurality of systems are integrated and controlled by the same controller or multiplex transmission apparatus (see Patent Document 1). .

  FIG. 6 shows a configuration example of a general digital control system of a large-scale plant. The control system includes a controller C1, C2,..., A multiplex transmission device RM1, RM2,..., A field device E1, E2,. , E6,... And a field cable MC that connects the input / output board IO mounted on the multiplex transmission apparatus.

  In a large-scale plant, it is divided into several systems according to functions and control purposes, and the on-site equipment E1, E2, ..., E6, ... belongs to one system, but a set of equipment belonging to different systems has one equipment. May be configured. For example, the device E3 in FIG. 6 indicates that there are devices of different systems in one device, and a plurality of field cables for exchanging signals between these devices and the controller are connected. The controller C1 has functions SA and SC for controlling the systems A and C, and the controller C2 has functions SB and SD for controlling the systems B and D. Implemented in one of these.

When the sensor belonging to the system B is the device E1 and the actuator is the device E5, the process value measured by the device E1 is input from the input board mounted on the multiplex transmission device RM1, and the multiplex transmission device RM1 The data is transmitted and output to the control network NC toward the controller C2 having a control function. The controller C2 receives the process value and is used for control calculation. A control command signal based on the calculation result is output from the controller C2 to the control network NC toward the device E5, received by the multiplex transmission device RM2, and output from the output board connected to the device E5. Accordingly, the device E5 operates.
JP 2000-214913 A

  In the conventional control system described above, even if one multiplex transmission device is updated or one controller is updated, it is necessary to simultaneously stop a plurality of systems related to the device to be updated. Since it is affected by renewal, it takes time for the characteristic test after renewal. Therefore, there is a problem that the plant stop period is prolonged, and a control system that shortens the renewal period is required.

  The present invention has been made in order to solve the above-described problems, and can improve the operating rate of the digital control system by eliminating the need to stop the system when updating each device / equipment constituting the digital control system. It is an object of the present invention to make it possible to easily perform the characteristic test and to shorten the renewal period.

In order to achieve the above object, a digital control system according to the present invention includes at least one digital controller, a control network to which the digital controller is connected, a plurality of field devices arranged in the field, and the field device. A transmission device that inputs and outputs transmission signals, a plurality of field networks to which the transmission devices are connected, and a plurality of units that collectively and relay transmission signals between the control network and the plurality of field networks includes a transmission relay device, and each site network in the plurality of field network has a selection function of selectively connecting to said plurality of transmission relay device, wherein the plurality of transmission repeater Of the plurality of field devices by the digital controller when replacing some of the transmission relay devices. That is configured to be continued, and said.

In addition, an operation method of a digital control system according to the present invention includes at least one digital controller, a control network to which the digital controller is connected, a plurality of field devices arranged on the site, and each of the field devices. A plurality of transmission relays for controlling and relaying transmission signals between the attached transmission device for inputting / outputting transmission signals, a plurality of field networks to which the transmission devices are connected, and the control network and the plurality of field networks a method of operating a digital control system having devices with the respective site network in the plurality of field network, selects and connects the selected function for selectively connecting to said plurality of transmission repeater When replacing a part of the plurality of transmission relay apparatuses, Continuing the control of the plurality of field devices by Tal controller, characterized by.

  According to the present invention, it is possible to improve the operating rate of the digital control system by eliminating the need to stop the system when updating each device / equipment constituting the digital control system, and to easily perform the characteristic test after the update. The renewal period can be shortened.

[First Embodiment]
A first embodiment of a digital control system according to the present invention will be described with reference to FIG. This digital control system includes one or more controllers C1, C2,..., CL that perform control operations, a plurality of transmission relay devices N1, N2,... NM that relay transmission signals between networks, and field devices ( Field devices) E1, E2,... EN. Field devices E1, E2,... EN are generally sensors and actuators, and each has transmission devices T1, T2,.

  The digital control system further includes a control network NC that performs transmission between the controllers C1, C2,..., CL and the transmission relay apparatuses N1, N2,... NM, and transmissions with the transmission relay apparatuses N1, N2,. , FM that performs transmissions between the devices T1, T2,..., TN, and a plurality of transmission relay devices N1, N2,..., FM as connection destinations of the field networks F1, F2,. It has selection functions S1, S2,..., SM for selecting one from NM.

  .., NM and transmission network devices T1, T2,..., TN are simpler than the conventional configuration of a star network composed of multiple transmission devices. Thus, a transmission path selection function can be realized.

  In FIG. 1, the selection range of the selection function S1 is set to the transmission relay device N1 and the transmission relay device N2 in order to simplify the configuration expression, but a plurality of switching destinations such as the transmission relay devices N2, N3,. You may do it.

  In the example shown in FIG. 1, for example, if the device E1 is a sensor, the process value measured by the device E1 is converted into an electrical signal by the transmission device T1, and then output as a transmission signal to the site network F1. Since the selection function S1 is selected to connect the on-site network F1 and the transmission relay device N1, the transmission relay device N1 receives the process value. The transmission relay device N1 outputs the received process value to the control network NC, and if the controller that uses the process value measured by the device E1 for control calculation is C2, the controller C2 receives the process value. Is used for the control operation.

  If the actuator is the device E5, the control command signal based on the calculation result is output from the controller C2 to the control network NC toward the device E5, and the transmission relay device N2 receives this control signal. Since the selection function S2 is selected to connect the transmission relay device N2 and the field network F2, the transmission relay device N2 outputs the received control command signal as a transmission signal to the field network F2, and is attached to the device E5. The transmission device T5 receives the control command signal. The device E5 operates according to the received control command signal.

  When the connection destination of the on-site network F1 is switched to the relay transmission device N2 by the selection function S1, the device E1 is measured by the device E1 if the device E1 is a sensor, the controller C2 is an arithmetic device, and the actuator is an device E5. The process value is converted into an electrical signal by the transmission device T1, and then output as a transmission signal to the field network F1. Further, since the selection function S1 is selected to connect the field network F1 and the transmission relay device N2, the transmission relay device N2 receives the process value. The transmission relay device N2 outputs the received process value to the control network NC, and the controller C2 receives the process value. This process value is used for the control operation.

  A control command signal based on the calculation result is output from the controller C2 to the control network NC toward the device E5, and is received by the transmission relay device N2. Since the selection function S2 is selected to connect the transmission relay device N2 and the field network F2, the transmission relay device N2 outputs the received control command signal as a transmission signal to the field network F2, and is attached to the device E5. The transmission device T5 receives the control command signal. The device E5 operates according to the received control command signal.

  According to this embodiment, the transmission apparatuses T1, T2,..., TN are distributed to the individual devices E1, E2,..., EN, so that the transmission apparatuses T1, T2,. The corresponding devices E1, E2,..., EN can be updated simultaneously with updating. Thereby, the partial update limited to the range related to the transmission apparatuses T1, T2,. Therefore, the update period can be shortened as compared with the conventional configuration including the multiplex transmission apparatus and the input / output board in which the influence range at the time of update covers all signals handled by the apparatus itself.

  In addition, when the transmission relay devices N1, N2,... NM are updated by the selection functions S1, S2,..., SM, other transmission relay devices that continue to operate the connection of the on-site networks F1, F2,. By switching to N1, N2,..., NM, control can be continued without stopping the transmission of the controllers C1, C2,..., CL and the devices E1, E2,. As a result, it is possible to increase the update opportunities of the transmission relay apparatuses N1, N2,... NM, and to eliminate the isolation work and cable removal / connection work related to the devices E1, E2,. As a result, the update period can be shortened as compared with a system composed of a conventional multiplex transmission apparatus that requires isolation work related to stopping and stopping of the controlled system at the time of update.

[Second Embodiment]
A second embodiment will be described with reference to FIG. Here, the same or similar parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the second embodiment, a transmission relay device N1 that relays transmission signals between networks includes an isolation signal selection function SS1, a first simulation function SE1, and a second simulation function SE1a. The isolation signal selection function SS1 is for stopping / resuming transmission processing of an arbitrarily designated signal in the data D1 to be transmitted. The first simulation function SE1 performs writing holding / release of a value specified for the control network NC side signal in which transmission processing is stopped. The second simulation function SE1a performs writing holding / release of the value specified for the on-site network F1 side signal whose transmission processing is stopped.

  If the isolation function SS1 performs data selection in units of signals for the data D1 that the transmission relay device N1 performs transmission processing, and designates the transmission processing stop of the selected data, the controller and the device for the signal Communication stops. By the first and second simulation functions SE1 and SE1a, the signal values for which transmission processing is stopped by the isolation function IS1 are independently forcibly simulated on the control network NC side and the on-site network F1 side. . As a result, the controller and the device each recognize the forced simulated value. An interlock that can be executed only when the signal is not forcibly simulated is provided by restarting and stopping the transmission by the isolation function IS1.

  According to the present embodiment, when the device E1 is a sensor, when the transmission device T1 and the device E1 are updated, the process value transmitted to the controller C1 is isolated before the update, whereby the update device possessed by the controller C1 is obtained. The unnecessary operation of the interlock concerned is prevented, and the control can be continued by suppressing the influence on other devices. Thereby, an update period can be shortened. Further, when the device E1 is an actuator, when the controller C1 is updated, the control command signal transmitted to the device E1 is isolated before the update, so that it is not necessary to stop the device E1, and the device can be stopped and re-operated. No startup work is required.

  Since these isolations can be easily and intensively performed by the transmission relay device N1, the isolation work time is shortened and the update period is shortened compared to the conventional configuration in which the isolation points are dispersed in each controller. can do.

[Third Embodiment]
A third embodiment will be described with reference to FIG. Here, parts that are the same as or similar to those in the first or second embodiment are denoted by common reference numerals, and redundant description is omitted. In the third embodiment, a transmission relay device N1 that relays transmission signals between networks includes a test signal application function ST1. The test signal application function ST1 includes a test signal application function ST1 that applies a test signal that is arbitrarily set to a control command signal that is arbitrarily designated in the data D1 that is to be transmitted, and any data D1 that is to be transmitted. And a signal monitoring function SM1 for collecting and monitoring a designated signal.

  The test function TS1 performs data selection for each control command signal in the data D1 for which the transmission relay device N1 performs transmission processing data, and transmits the selected data. When a test signal arbitrarily set by the test signal application function ST1 is added during this transmission processing, a control command signal on which the test signal is superimposed is transmitted and output to the site network F1 side. The equipment of the on-site network F1 operates with a control command signal on which a test signal is superimposed, and the process value response of the operation result and the fluctuation of the equipment state are collected as data from the previous stage of the transmission processing circuit with the signal monitor function SM1, Response and fluctuation evaluation can be performed.

  According to this embodiment, it is not necessary to prepare test equipment separately, and the closed loop characteristic test can be performed during the control by the controller C1 performed after the transmission device T1 and the device E1 are updated. Moreover, if it is used together with the isolation function described in the second embodiment, it can also be applied to a single characteristic test of an apparatus in an open loop.

  Since these characteristic tests can be easily and intensively performed by the transmission repeater N1, the time required for the characteristic test work is shortened compared to the conventional configuration that does not have a test function or is distributed to each controller. In addition, the update period can be shortened.

[Fourth Embodiment]
A fourth embodiment will be described with reference to FIGS. 4 and 5. Here, parts that are the same as or similar to those in the first to third embodiments are denoted by common reference numerals, and redundant description is omitted. In the fourth embodiment, as shown in FIG. 4, a plurality of systems (A to D) to be controlled are provided to a plurality of controllers C1, C2,..., CL of the digital control system in the first embodiment. Control functions SA,..., SD. Further, as shown in FIG. 5, the transmission relay apparatuses N1, N2,..., NM are configured to have signal selection functions V1, V2,.

  In FIG. 4, assuming that the device E1 is a sensor and the device E2 is an actuator, and these devices belong to the system C, the process value measured by the device E1 is converted into an electrical signal by the transmission device T1, and then the on-site network. It is output as a transmission signal to F1. Since the selection function S1 is selected to connect the on-site network F1 and the transmission relay device N1, the transmission relay device N1 receives the process value. The transmission relay device N1 outputs the received process value to the control network NC, and the process value measured by the device E1 is received by all the controllers C1, C2,. Used for.

  Control command signals based on the calculation results are individually output from the controllers C1, C2,..., CL to the control network NC toward the device E2, and are received by the transmission relay device N1. In the signal selection function VT1 in FIG. 5, the control command signal transmitted from each controller C1, C2,..., CL is selected. As the selection method, in the case of an analog signal, high value selection, low value selection, intermediate value selection, and the like are performed depending on the signal. In the case of a digital signal, OR selection, AND selection, etc. are performed. By these combinations, 2/3 selection (selection by majority of 3 signals) and 2/4 selection can be performed.

  Since the selection function S2 is selected to connect the transmission relay device N2 and the field network F2, the control command signal selected by the signal selection function VT1 is output to the field network F1 as a transmission signal and attached to the device E2. The transmission device T2 receives the control command signal. The device E2 operates according to the received control command signal.

  According to this embodiment, since the system control function is mounted on a plurality of controllers, the control function is not lost even if one controller stops. As a result, it is possible to continue control with the non-updating controller even during the controller update period, and the update period can be shortened or unnecessary compared to the conventional configuration where the controlled system must be stopped when the controller is updated. Become.

  Further, by providing the signal selection function in the transmission relay device, the signal selection function in each controller becomes unnecessary. Thereby, the quantity of the goods which comprise a controller can be reduced, and cost can be held down. In addition, since the calculation processing results of multiple controllers are selected and output to the actuator, normal control can be continued by selecting appropriate signals even when one controller is abnormal, improving the operating rate of the control system It also has the effect of

1 is a configuration diagram of a digital control system according to a first embodiment of the present invention. The block diagram of the transmission relay apparatus which concerns on the 2nd Embodiment of this invention. The block diagram of the transmission relay apparatus which concerns on the 3rd Embodiment of this invention. The block diagram of the digital control system which concerns on the 4th Embodiment of this invention. The block diagram of the transmission relay apparatus which concerns on the 4th Embodiment of this invention. The block diagram of the conventional digital control system.

Explanation of symbols

C1, C2,..., CL: Controllers N1, N2,..., NM: Transmission relay devices S1, S2,..., SM: Selection functions T1, T2, ..., TN: Transmission devices E1, E2,. Field equipment)
NC: Control network F1, F2,..., FM: Field network

Claims (7)

At least one digital controller;
A control network to which the digital controller is connected;
A plurality of field devices arranged on the site;
A transmission device attached to each of the field devices for inputting and outputting transmission signals;
A plurality of field networks to which the transmission device is connected;
A plurality of transmission relay devices for controlling and relaying transmission signals between the control network and a plurality of field networks;
Have
Each site network in the plurality of site networks has a selection function of selecting and connecting to the plurality of transmission relay devices,
A digital control system configured to continue control of the plurality of field devices by the digital controller when replacing some of the plurality of transmission relay devices . 2. The digital control system according to claim 1, wherein the transmission relay device has an isolation function for stopping and restarting transmission processing of an arbitrarily designated signal among data transmitted by the transmission relay device. . The transmission relay device has a function of applying a test signal and collecting a response signal, and when any of the transmission relay device, the transmission device, or the field device is updated, it is possible to perform a confirmation test on an update target. The digital control system according to claim 2 , wherein the digital control system is configured. 3. The digital control system according to claim 2 , wherein the transmission relay device has a function of transmitting a value that is forcibly simulated to at least one of the digital controller and field equipment .   The digital controller is composed of a plurality of units, and each digital controller is provided with software capable of controlling the transmission relay device, the transmission device, and the field device connected to the digital controller, and at the time of failure and update of the digital controller. 5. The digital control system according to claim 1, wherein mutual backup is possible, and the transmission relay device has a function of selecting a transmission signal from the digital controller. 6. .   6. The function of the transmission repeater to select a transmission signal from the digital controller includes at least one of a 2/3 selection function and a high / low / intermediate value selection function. Digital control system. At least one digital controller;
A control network to which the digital controller is connected;
A plurality of field devices arranged on the site;
A transmission device attached to each of the field devices for inputting and outputting transmission signals;
A plurality of field networks to which the transmission device is connected;
A plurality of transmission relay devices for controlling and relaying transmission signals between the control network and a plurality of field networks;
A method for operating a digital control system comprising:
Each on-site network in the plurality of on-site networks is selected and connected by a selection function for selecting and connecting to the plurality of transmission relay devices,
An operation method of a digital control system, characterized in that control of the plurality of field devices by the digital controller is continued when replacing some of the plurality of transmission relay devices .

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