JPS6160198A - Signal transmitter for process instrumentation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a signal transmission device for process instrumentation that transmits various signals used for process instrumentation in nuclear power plants and the like.

[Technical background of the invention] In nuclear power plants, process instrumentation uses pressure, differential pressure,
Various process signals such as flow rate are used, and these signals are transmitted to the process instrumentation rack 1 as shown in Figure 5.
A large number of transmitters 3 housed in the terminal are collected at a relay terminal of a relay terminal block 51, and from these relay terminals are connected via cables to an indicator 11, a recorder 131, . It is transmitted to the controller 115, etc., and can be monitored in the central control room. However, in this conventional process-through single-use signal transmission device, in order to transmit each signal from each transmitter 3, for example, a pair of cables are required per transmitter, as shown in FIG. , a leash line, using two cables each. In other words, a power source 53 is connected to one end of this cable, a resistor 55 is connected to the other end that returns to the central control room via the transmitter 3, and the voltage across this resistor is detected. ing.

For this reason, in order to transmit a large number of process instrumentation signals, the number of cables increases in proportion to the number of transmitters, which requires a lot of time and money for wiring work and maintenance, and also causes problems with reliability and reliability. be.

[2.Object of the invention] This invention was made in view of the above, and its purpose is to reduce the number of cables, reduce the time and cost of wiring work and maintenance, and increase reliability of explosives. An object of the present invention is to provide an improved signal transmission device for process cutting.

[Summary of the Invention] In order to achieve the above object, the present invention multiplexes and transmits various signals for process instrumentation using a multiplex transmission means, and receives the multiplexed signals from the multiplex transmission means using a receiving means. The gist is that.

[Embodiments of the invention] The present invention will be described in detail below using the drawings.

FIG. 1 shows a process control signal transmission device according to an embodiment of the present invention.

This process instrumentation signal transmission device has a plurality of process instrumentation racks 1, one for each process, and supplies a large number of signals from each transmitter 3 housed in the rack 1 to a transmitter 5. A transmitter 5 controls each signal in a time-division manner and sequentially transmits the signals to a receiver 9 on the central operation room side via a single cable 7. In this case, the analog signal from each transmitter 3 is converted into a digital signal by the transmitter 5, and is repeatedly transmitted to the receiver 9 on the central operation room side at a constant cycle. The receiver 9 receives the digital signals sequentially transmitted in a time-division manner from the desired process instrumentation rack 1, converts them into analog signals, and is installed in the central operation room according to the allocation for each signal. instruction tears 11
, recorder 13, controller 15, and output to 41117. In addition, the transmitter 5 attaches a code to the transmitted signal to detect transmission errors, and when the signal is received by the receiver 9, the transmitted data is determined as desired by checking this code. It is now possible to detect transmission errors such as not coming from a process instrumentation rack or not coming from the desired transmitter. If a transmission error is detected, the received signal is canceled, output to each instrument in the central control room is stopped, and a request is made to the transmitter 5 to retransmit the signal. . FIG. 2 is a detailed diagram of the transmitter 5 and receiver 9 of FIG.

In the figure, the transmitter 5 includes a multiplexer 21 that receives signals from a plurality of transmitters 3 and multiplexes these signals, and an A-'D converter that converts the output signal of the multiplexer 21 into a digital signal. 23, an encoder 25 for encoding the output signal of this A-D converter 23, and an encoder 25 for sending the output signal from this encoder 25 to the central operation room side and for receiving signals from the central operation room side. It consists of an input/output control section 27, a self-data judgment section 28 that judges whether the received signal is assigned to itself, and a control unit 29 that controls each section. In addition, the receiver 9 on the side of the central operation room includes an input/output control section 31 for appropriately receiving signals from the plurality of transmitters 5 and sending signals to the transmitters 5; A decoder 33 that decodes the received signal from the transmitter 5, a DA converter 35 that converts the signal from the decoder 33 into an analog signal, and an indicator 11, which converts the analog signal from the DA converter 35 into an analog signal. It is comprised of a multiplexer 37 that distributes to the controller 15, computer 17, etc., and a control unit 39 that controls each part.

Next, the operation of this device will be explained.

Data transmission to this device is carried out at regular intervals in the order of channel registration under the control of the control unit 39 of the receiver 9 in the central operation room. That is, first, the receiver 9 issues a transmission request to the transmitter 5 of the professional wrestling rack from which data is to be obtained. The transmitter 5 receives this transmission request via the input/output control section 27, and after confirming that the transmission request has been made to itself at the self-data judgment section 28, the control unit 29 determines which transmitter it is. , that is, which channel's signal is to be transmitted, and outputs a reading command for that channel to the multiplexer 21 . multiplexer 21
The signal read from the receiver is converted into a digital signal by an eight-way converter 23, encoded by an encoder 25 as a transmission signal, and transferred from an input/output controller 27 to a receiver 9.

In the receiver 9, the input/output control unit 31 receives this signal and checks whether the received signal is of the desired channel of the requested process instrumentation rack and whether there is a transmission error. the received signal is of the desired channel of the requested process instrumentation rack;
And if there is no transmission error, the decoder 33 and D
- Converted to an analog signal via the A converter 35, and sent from the multiplexer 37 to the indicator 11, adjustment 15, and scale calculator 17.
Output to etc.

In data transmission, an interrupt from the computer 17 is checked each time data transmission of one channel is completed, and if there is an interrupt, data transmission to the computer 17 is performed with priority.

FIG. 3 is a flowchart showing this effect.

This flowchart will be explained. The data transmission for the n-th channel is performed until the data transmission is completed, and when the data transmission is completed, it is checked whether there is an interrupt from the computer 17 (steps 110, 120, 130). Here, according to the rule 17, data is transmitted to the computer 17 of the n-th channel on which the data transmission has been completed to the platform where the interruption occurs (step 140).

When this data transmission is completed, data transmission of the (n+1)th channel is performed next (as a result of step 16, if there is no interruption from the 31 calculator 17, the data transmission is directly performed in step 160).
Then, data transmission of the (n+1)th channel is performed.

Note that in the embodiments described above, a method of transmitting data using light may be used. In this case, a multiplex optical communication cable is used between the cables 7, and the transmitter 5 and receiver 7
For this purpose, a photoelectric converter may be used.

FIG. 4 shows another embodiment of the invention.

This embodiment uses the transmitter 5 of each professional wrestling rack 1 in the process wiring signal transmission apparatus shown in FIG.
The only difference is that a signal selector 41 and a signal scanner 43 are used in place of the receiver 9 in the central operation room.

The signal selector 41 is supplied with a plurality of process signals from the plurality of transmitters 3, and these signals are sequentially selected by control signals from the signal scanner 43 and output from the signal selector 41 to the signal scanner 43. Ru.

The signal scanner 43 receives these selected signals and outputs them to the indicator 11, recorder 13, controller 15, scale calculator 17, etc.

[Effects of the Invention] As explained above, according to the present invention, since various signals for process instrumentation are multiplexed and transmitted, a large number of signals can be transmitted with one cable, The time and cost required for wiring work and maintenance can be reduced, and the reliability of the device can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a signal transmission device for process instrumentation showing an embodiment of the present invention, FIG. 2 is a detailed diagram of the device shown in FIG.
Figure 3 is a flowchart explaining the operation of Figure 2;
The figure is a block diagram of a signal transmission device for process instrumentation showing another embodiment of the present invention, FIG. 5 is a block diagram of a conventional signal transmission device for process instrumentation, and FIG. 6 shows the flow of the cable in FIG. 5. It is a diagram. DESCRIPTION OF SYMBOLS 1... Process instrumentation rack, 3... Transmitter, 5... Transmitter, -〇 -^r -Chang - 9... Receiver.

Claims (1)

[Claims] 1. A signal transmission device for process instrumentation, comprising: multiplex transmission means for multiplexing and transmitting various signals for process instrumentation; and receiving means for receiving the multiplexed signals from the multiplex transmission means.