JPH0627818B2 - Radiation monitor system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiation monitoring system, and more particularly to a radiation monitoring system of a type in which a transmission line is provided between a radiation detector and a monitoring device used in a nuclear power plant or the like.

[Technical background of the invention]

FIG. 8 shows a schematic configuration diagram of a conventional radiation monitor system. The detector 11 has a radiation sensor 12, a calibration circuit 13, a changeover switch 14, and an output buffer 15. The monitor device 17 has a high-voltage power supply 18, a low-voltage power supply 19, and a discriminator 2.
0, a discrimination level setter 21, a switching circuit 22, and a processing circuit 23. In order to connect the above elements,
A multi-core cable 16 is provided between the detector 11 and the monitor device 17.
Are joined by. Generally, the detector 11 is installed in the field, and the monitor device 17 is installed in an operation place apart from this to ensure the safety of the operator. Electric power is supplied to the detector 11 from the high-voltage power supply 18 and the low-voltage power supply 19 via the multicore cable 16. The detection signal detected by the radiation sensor 12 is driven by the output buffer 15 and transmitted to the monitor device via the multicore cable 16. This detection signal is compared by the discriminator 20 with the level set in the discrimination level setting device 21, processed by the processing circuit 23, and the alarm circuit 24 is activated or recorded in the recorder 25. Further, when performing the calibration, the changeover switch is switched so that the output of the calibration circuit 13 is transmitted instead of the radiation sensor 12 by the switching signal from the switching circuit 22, and the calibration is performed.

[Problems of background technology]

Generally, an electronic power plant or the like uses a multi-channel monitor system. That is, as shown in FIG. 9, N detectors 11-1 to 11-N are installed in the field, and N monitor devices 17-1 to 17-N are installed in the operation place correspondingly. It Moreover, a multi-core cable 1 is provided between them.
Since 6-1 to 16-N are provided, the system configuration of 1 channel is required for N channels as it is. This not only increases the installation cost but also requires a considerably large installation space. Also,
Even in a 1-channel system, an expensive multi-core cable is required in the conventional system because the multi-core cable serves as a supply path for various signals such as detection signals and various power sources as shown in FIG. This also causes external noise to occur in various signals, which causes a decrease in SN, erroneous counting of the monitor device, and the like, which hinders accurate measurement.

[Object of the Invention]

Therefore, an object of the present invention is to provide a radiation monitor system capable of ensuring an efficient transmission system even in a monitor system of a plurality of channels.

[Outline of Invention]

A feature of the present invention is that a plurality of detectors that perform radiation detection by a radiation sensor based on an input control signal and that outputs a detection signal indicating the detection result, and that the control signal is output to each of these detectors. In addition, the radiation monitor system is provided with one monitor device for inputting the detection signal from each of these detectors, and a signal line for transmitting the control signal and the detection signal in a time division manner. A first transmission detection circuit provided in the detector for determining whether the detection signal is being transmitted, and prohibiting the input of the control signal when the detection signal is being transmitted, and A first transmitter having a first gate circuit that receives an input of the control signal when the detection signal is not being transmitted, and whether or not the control signal is being transmitted, which is provided in the monitor device. A second transmission detection circuit for judging, and a second gate for inhibiting the input of the detection signal when the control signal is being transmitted and accepting the input of the detection signal when the control signal is not being transmitted. And a second transmitter having.

Example of Invention

Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a schematic configuration diagram of this embodiment. This radiation monitor system consists of N channels, and N
The detectors 31-1 to 31-N are provided. Each detector 31 has a serial transmitter (corresponding to the first transmitter of the present invention) 32. A field unit 34 is provided near the N detectors 31. The field unit 34 has N serial transmitters 35-1 to 35-N and a digital serial transmitter 37. The N serial transmitters 35-1 to 35-N are the N detectors 31-1 to 3
1-N is connected to each of the coaxial cables 33-1 to 33-N. On the other hand, the digital serial transmitter 37 is connected to the N serial transmitters 35-1 to 35-N by a connection line 36. The monitor device 39 is provided at an operation place away from the site and has a serial transmitter (corresponding to the second transmitter of the present invention) 40 and a signal processing circuit 42. The digital serial transmitters 37 and 40 are connected by one optical transmission line 38. The digital serial transmitter 40 and the signal processing circuit 42 are connected by a digital bus 41, and the signal processing circuit 4
2 gives a signal to the alarm circuit 24 and the recorder 25.

FIG. 2 shows a detailed configuration of the digital serial transmitter 40. The command from the digital bus 41 is the address register 4
8 and the transmission data register 49, and the outputs of these registers are sent to the optical transmission line 38 via the optical driver 43 and the optical multiplexer 44. The address register 48 contains data as to which setting value of which detector out of the N detectors is to be selected, and the transmission data register 49 contains data to be transmitted to the selected detector as serial data. Given. Optical driver 43
Is composed of a photoelectric conversion element, converts the given electric signal into an optical signal and gives it to the optical multiplexer 44. On the other hand, the optical multiplexer 44 also receives the data sent from the optical transmission line, and gives the received optical signal to the optical receiver 45. The optical receiver 45 is composed of a photoelectric conversion element, converts a given optical signal into an electric signal, and gives it to the reception data register 50 via the AND gate 47. Also, register 4
The output signals of 8 and 49 are given to the transmission detection circuit (corresponding to the first transmission detection circuit of the present invention) 46, and the transmission detection circuit 46 detects the transmission and the AND gate (the first gate of the present invention). Signal corresponding to the circuit) 47 to close the gate. By providing the AND gate 47 in this manner, even if the transmission optical signal is given to the optical receiver 45 through the optical multiplexer, the AND gate 47 is closed and the transmission data is not given to the reception data register 50.

FIG. 3 shows a detailed configuration of the field unit 34. The digital serial transmitter 37 has the same structure as the part shown by the broken line of the digital serial transmitter 40 in FIG. 2, and the same reference numerals are given to the respective components and the description thereof will be omitted. The serial transmitter 35 includes a signal driver 53, a signal receiver 54, a transmission detection circuit 46, an AND gate 47, and a low pass filter 5.
5, high-pass filter 56, and low-voltage power supply 19. The digital serial transmitter 37 has an optical transmission line 38.
And the electrical signal transmitted through the connection line 36 are mutually converted. The signal driver 53 and the signal receiver 54 are connected to the coaxial cable 33 via a high-pass filter 56.
To and from. The transmission detection circuit 46 and the AND gate 47 serve as an input gate of the reception unit so that the transmission signal does not enter the reception unit during transmission. Further, the low voltage power supply 19 is connected to the coaxial cable 33 via the low pass filter 55, and low voltage power transmission is also performed.

FIG. 4 shows the detailed structure of the detector 31. The low voltage transmitted from the coaxial cable 33 is given to the low voltage power source 19 via the low pass filter 55. Also, the signal driver 5
3 and the signal receiver 54 perform transmission to and reception from the coaxial cable 33 via the high-pass filter 56. Transmission detection circuit (corresponding to the second transmission detection circuit of the present invention)
46 and an AND gate (corresponding to the second gate circuit of the present invention) 47 serve as an input gate of the receiving unit so that the transmission signal does not enter the receiving unit during transmission. The received signal is given to the address register 68 and the received data register 69. An address value of the detector is set in the detector address setting unit 66. As the address value, for example, the number of the detector from 1 to N can be used. The decoder 67 compares this address value with the data given to the address register 68, and if they match, it judges that the detector is selected and gives an operation command (shown by the broken line in the figure) to each device. . A high voltage is supplied to the radiation sensor 12 from a high voltage power supply 18. The output of the radiation sensor 12 is the changeover switch 14
Is given to the discriminator 20 via. The discriminator 20 is also given the discrimination level set by the discrimination level setting device 21, and gives a signal to the counter 61 when the output of the radiation sensor 12 is equal to or higher than the discrimination level. The counter 61 counts this signal and gives the count result to the measurement data register 64. On the other hand, at the time of calibration, the changeover switch 22 switches the changeover switch 14, and the output of the calibration circuit 13 is supplied to the discriminator 20 in place of the output of the radiation sensor 12 to perform calibration. Also, the output voltage of the high voltage power supply 18,
Tube current of radiation sensor 12 and discrimination level setting device 2
The identification level set in 1 is passed through the multiplexer 62 and the A / D converter 63 to the diagnostic data register 65.
Given to. The data of the measurement data register 64 and the diagnostic data register 65 are sent to the coaxial cable 33 by the signal driver 53. The high-voltage power supply 18, the switching circuit 22, and the discrimination level setting device 21 are conditionally set based on the contents of the reception data register 69.

Next, the operation of the present embodiment when various conditions of the detector 31 are set by the monitor device 39, the measured data is read out, calculated, and the result is output to the alarm circuit 24 and the recorder 25 will be described. First, data required for measurement is sent from the signal processing circuit 42 to the digital serial transmitter 40 through the digital bus 41. Now, considering the case of setting the discrimination level of the n-th detector, for example, the detector address data for selecting the discrimination level setting of the n-th detector is stored in the transmission data register in the address register 48 in FIG. Is provided with transmission data corresponding to the identification level to be set. These data are converted into an optical signal by the optical driver 43, and the optical multiplexer 44
Is transmitted to the optical transmission line 38 via. This transmission data is sent in the form of digital serial data in the order of detector address data and transmission data as shown in FIG. 5 (a), for example. At this time, since the AND gate 47 is closed as described above, no transmission data is sent to the reception data register 50.

The optical signal transmitted through the optical transmission line 38 is given to the optical receiver 45 via the optical multiplexer 44 in the field unit 34 as shown in FIG. 3, and is converted into an electric signal here. Further, it is sent to the connection line 36 via the AND gate 47. The connection line 36 branches into N lines from here, and transmits the same signal to the N serial transmitters 35-1 to 35-N.
In the serial transmitter 35, the signal from the connection line 36 is transmitted to the coaxial cable 33 by the signal driver 53.
At this time, the AND gate 47 is closed, so that the transmission data is not detected as the reception data. Since a low voltage may be supplied to the coaxial cable 33 from the low voltage power source 19, a low pass filter 55 and a high pass filter 56 are provided. That is, the transmission data is output to the coaxial cable 33 through the high-pass filter 56, but does not enter the low-voltage power supply 19 because it is blocked by the low-pass filter 55. On the contrary, the low voltage is supplied to the coaxial cable 33 through the low-pass filter 55, but does not enter the signal driver 53 and the signal receiver 54 because they are blocked by the high-pass filter 56.

The N detectors 31-1 to 31-N receive the same signal from the coaxial cables 33-1 to 33-N, respectively. This signal is received by the signal receiver 54 via a high pass filter 56, as shown in FIG. When low voltage power is supplied instead of transmission data, the low pass filter 55
Is supplied to the low-voltage power supply 19 in the detector 31 via. The transmission data is given to the address register 68 and the reception data register 69 via the AND gate 47. The detector address data given to the address register 68 is compared with the detector address set by the detector address setter in the decoder 67. If the two match, the specified device is set using the data given to the reception data register 69. Now
As described above, considering the case of setting the discrimination level of the nth detector, the address register 68 stores the detector address data designating the discrimination level setting of the nth detector, and the reception data register 69 stores the detector address data. Data corresponding to the set identification level will be received. Here, the detector addresses match only in the n-th detector 31-n among the N detectors 31-1 to 31-N. In the detector 31-n, the decoder 67 to the discrimination level setter 21 A setting signal (indicated by a broken line in FIG. 4) is sent to, and the setting data in the reception data register is set in the discrimination level setting unit. Similarly, when the high-voltage power supply 18 is designated, the output voltage value of the high-voltage power supply 18 is set, and when the switching circuit 22 is designated, the switching state is set. When the multiplexer 62 is designated, the output voltage of the high-voltage circuit 18, the tube current of the radiation sensor 12, and the identification level set by the identification level setter 21 are set by the A / D converter 63 as the diagnostic data register 65. Given to.

Next, the measurement data read operation will be described. The radiation pulse detected by the radiation sensor 12 is counted by the counter 61 via the discriminator 20, and the result is given to the measurement data register 64. When the decoder 67 gives a read command to the address register 68 and the reception data register 69 based on the data in the address register 68, the data in both registers is transmitted to the coaxial cable 33 by the signal driver 53. At this time, the operation of the AND gate 47 prevents the transmission data from being received in reverse. This transmission data is sent in the form of digital serial data in the order of detector diagnostic data and detector measurement data as shown in FIG. 5 (b), for example.

The transmission data from the nth detector 31-n is given to the field unit 34 through the coaxial cable 33-n. Here, it is transmitted from the serial transmitter 35-n to the digital serial transmitter 37, converted into an optical signal and transmitted to the optical transmission line 38. Finally, this optical signal is received by the monitor device 39, processed, and then output to the alarm circuit 24 and the recorder 25.

The setting and reading for the n-th detector have been described above, but this can be performed for all the detectors by repeating this N times.

Further, as shown in FIG. 6, M digital serial transmitters 40 are provided in the monitor device 39, and a field unit 34 is provided for each of them, thereby connecting M × N detectors to one monitor device. can do. As a result, it is possible to control a large number of detectors over a range of buildings with a single monitor device.

Also, as shown in FIG. 7, 1
In one monitor device 39, N digital serial transmitters 40-1 to 40-N are provided, and N detectors 31-
1 to 31-N and N coaxial cables 33-1 to 33-
It is also possible to connect directly with N. An example of such
It can be easily applied to the conventional example shown in FIG. 9 and is convenient. That is, the present invention is applied without re-laying the coaxial cable by using only one of the existing multi-core cables 16-1 to 16-N as the coaxial cables 33-1 to 33-N. it can.

〔The invention's effect〕

As described above, according to the radiation monitor system of the present invention, bidirectional signal transmission between a plurality of detectors and one monitor device can be performed in a time-division manner, so that an efficient transmission system can be realized. Can be secured.

Further, according to the present invention, since the detector is equipped with the first transmitter, there is no possibility that the detection signal transmitted from this detector is taken into the detector as a control signal. Similarly, since the second transmitter is mounted on the monitor device, there is no possibility that the control signal transmitted from the monitor device will be taken into the monitor device as a detection signal. Therefore,
Since it is possible to prevent erroneous input of the detection signal and the control signal, it is possible to ensure system reliability.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a radiation monitoring apparatus according to the present invention, FIG. 2 is a detailed configuration diagram of a digital serial transmitter of the apparatus shown in FIG. 1, and FIG. 3 is a site shown in FIG. FIG. 4 is a detailed block diagram of the unit, FIG. 4 is a detailed block diagram of the detector shown in FIG. 1, FIG. 5 is a time chart showing an example of a serial signal transmission pattern according to the present invention, and FIGS. Schematic block diagrams of another embodiment of the present invention, FIGS. 8 and 9
FIG. 1 is a schematic configuration diagram showing an example of a conventional radiation monitor device. 11 ... Detector, 12 ... Radiation sensor, 13 ... Calibration circuit, 14 ... Changeover switch, 15 ... Output buffer,
17 ... Monitor device, 16 ... Multi-core cable, 18 ...
High-voltage power supply, 19 ... Low-voltage power supply, 20 ... Discriminator, 21 ...
... discrimination level setting device, 22 ... switching circuit, 24 ... alarm circuit, 25 ... recorder, 31 ... detector, 32 ... serial transmitter, 33 ... coaxial cable, 34 ... field unit, 35 ... … Serial transmitter, 36 …… Connection line, 3
7: Digital serial transmitter, 38: Optical transmission line, 3
9 ... Monitor device, 40 ... Digital serial transmitter,
41 ... Digital bus, 42 ... Signal processing circuit, 43 ...
... optical driver, 44 ... optical multiplexer, 45 ... optical receiver, 46 ... transmission detection circuit, 47 ... AND gate, 48 ... address register, 49 ... transmission data register, 50 ... reception data register, 53 ...... Signal driver, 54 …… Signal receiver, 55 …… Low pass filter, 56 …… High pass filter, 61 …… Counter,
62 ... Multiplexer, 63 ... A / D converter,
64 ... Measurement data register, 65 ... Diagnostic data register, 66 ... Detector address setting device, 67 ... Decoder, 68 ... Address register, 69 ... Reception data register.

Claims (1)

[Claims] 1. A plurality of detectors for detecting radiation by a radiation sensor based on an input control signal and outputting a detection signal indicating the detection result, and outputting the control signal to each of these detectors. A radiation monitor system comprising a monitor device for inputting the detection signal from each of these detectors, and a signal line for transmitting the control signal and transmitting the detection signal in a time division manner, A first transmission detection circuit provided in the detector for determining whether or not the detection signal is being transmitted; and, when the detection signal is being transmitted, prohibiting the input of the control signal and A first transmitter having a first gate circuit that receives an input of the control signal when the detection signal is not being transmitted, and whether or not the control signal, which is provided in the monitor device, is being transmitted. Size And a second gate for inhibiting the input of the detection signal when the control signal is being transmitted and accepting the input of the detection signal when the control signal is not being transmitted. A second transmitter, and a radiation monitor system comprising: