JPH06284474A - Monitoring device - Google Patents

Abstract

PURPOSE:To improve process monitoring accuracy by using a normal monitoring device by interposing and inserting a separation coupler modulating and demodulating the control signal for a detection signal in the signal path of the detection signal from a sensor with a communication function to a monitoring device main body. CONSTITUTION:The information request command signal transmitted from a personal computer 9 is superimposed on a process amount detection signal by a repeater 7 and a separation coupler 31 and is transmitted to a sensor with communication function 11. The detected information response signal extracted from the information superimposed signal that the sensor 11 transmits by the separation coupler 31 is transmitted to the personal computer 9 by the repeater 7. The personal computer 9 outputs detection information based on the detection information response signal. Therefore, a communication can be performed with the sensor with communication function by using a normal monitoring device main body as it is without disturbing the process amount detection signal of the sensor. When the communication is performed with the sensor with other communication function, communication can be performed only if the transmission destination of the information request command signal is changed and process monitoring accuracy can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for monitoring a process state of plant equipment by using a sensor, and particularly to easily add various control information to a detection signal from the sensor.
The present invention relates to a monitoring device that is provided with a technique for extracting and can easily remotely control a sensor.

[0002]

2. Description of the Related Art Conventionally, a monitoring device having a large number of sensors for detecting various process amounts such as pressure and flow rate has been widely used for controlling a plant.

This monitoring apparatus is connected to the above-mentioned many sensors and each sensor through a signal line, receives a detection signal indicating the process amount sent from each sensor, and receives each of the received detection signals. It is composed of a monitoring device body for monitoring the process amount. It should be noted that the detection signal transmitted from each sensor to the main body of the monitoring device is generally DC 4 to 20 m.
The analog signal of A is used.

In such a monitoring device, in order for the monitoring device body to accurately monitor the process state of each device of the plant equipment, each sensor must naturally send an accurate detection signal to the monitoring device body. is there.

In order to improve the detection accuracy of the process amount in each sensor, it is necessary to select the correct measurement range and adjust the zero point appropriately. Furthermore, it is necessary to grasp the information such as the tag number of each sensor, the material information of the liquid contact portion, the last maintenance and inspection date, etc., if necessary. In the conventional monitoring device, the above-described maintenance and management work of each sensor is performed by a worker to the sensor mounting position of each device in the plant equipment. Therefore, the burden of maintenance management work on the entire monitoring device increases. In order to avoid such an inconvenience, a sensor with a communication function has been developed.

This sensor with a communication function has a function of detecting the original process amount and sending it as an analog detection signal to the main body of the monitoring apparatus, as well as a digital signal indicating various commands and response information on the analog detection signal. By superimposing the control signal, bidirectional communication is possible with the monitoring device body.

As described above, by superimposing the digital control signal on the analog detection signal, the above-mentioned measurement range selection, zero point adjustment and the like in each sensor with communication function can be remotely operated from the monitoring device main body, and various maintenance can be performed. Inspection information can be collected and managed automatically.

[0008]

Therefore, if the conventional sensor having only the function of detecting and transmitting the process amount is replaced with the sensor having the communication function described above, the monitoring accuracy of the entire monitoring device is improved and maintenance is performed. It goes without saying that the work efficiency of management work can be improved, but in order to fully demonstrate the function of the sensor with communication function, the monitoring device itself also superimposes the digital control signal on the analog detection signal from each sensor with communication function. Command to each sensor with communication function,
It is necessary to add a function capable of transmitting / receiving each control signal for response. However, it requires a great deal of cost and time to replace or modify the monitoring device body with a device having the above-mentioned function.

The present invention has been made in consideration of the above circumstances, and modulates and demodulates command and response control signals in response to the detection signal in the signal path of the detection signal from the sensor with communication function to the main body of the monitoring apparatus. By inserting the separate coupler, the conventional monitoring device itself can be used as it is, the sensor with communication function can be remotely controlled, and various information other than the detection signal of the sensor with communication function can be collected, at low cost, An object of the present invention is to provide a monitoring device capable of significantly improving the process monitoring accuracy of plant equipment and simplifying the inspection and maintenance work for each sensor.

[0010]

The invention according to claim 1 is directed to a monitoring device main body for monitoring a process state of a plant device, a process amount in the plant device, and a detection signal corresponding to the detected amount. A sensor with a communication function that sends out to a monitoring device main body, extracts a command signal superimposed on the detection signal, performs processing corresponding to the command signal, and superimposes a response signal on the detection signal and sends the response signal. A separating / combining device which is inserted in a signal path of a detection signal from the sensor with a communication function to the monitoring device body, extracts a response signal superimposed on the detection signal, and superimposes a command signal on the detection signal. And sending a command signal to the sensor with communication function via the separation coupler to receive a response signal from the sensor with communication function, Kicking a monitoring device including a sensor control unit for controlling the detecting operation of the process amount. It should be noted that, in particular, the separating / combining unit may superimpose / extract the command signal and the response signal, which are digital signals, on the detection signal, which is an analog signal of DC 4 to 20 mA.

[0011]

Therefore, according to the invention corresponding to claim 1, by taking the above-mentioned means, the sensor control device sends the command signal while the sensor with communication function sends the detection signal to the monitoring device body. The command signal received by the separate coupler from the sensor control device is superimposed on the detection signal, and the sensor with communication function extracts the command signal superimposed on the detection signal and executes the processing corresponding to the command signal. Further, the response signal is superimposed on the detection signal and sent out, the separation coupler extracts the response signal superimposed on the detection signal, and the sensor control device receives the response signal from the coupling separator.

As a result, the sensor with the communication function can be remotely controlled, and various information other than the detection signal of the sensor with the communication function can be collected, and the process monitoring accuracy for the plant equipment can be greatly improved at a low cost, and Inspection and maintenance work for the sensor can be simplified.

In the invention corresponding to claim 2, the separating / combining device superimposes a command signal and a response signal, which are digital signals, on a detection signal which is an analog signal of DC 4 to 20 mA.
Since the extraction is performed, in addition to the effect of the invention corresponding to claim 1, it can be easily applied to the plant equipment currently put into practical use.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a monitoring device according to the first embodiment of the present invention.

In this monitoring device, fourteen sensors 1 ₁ to 1 ₁₆ each having ₁₆ communication functions are connected to one of the corresponding four separate couplers 3 _{1 to} 3 ₄ via a sensor side signal line 2. The four separate couplers 3 _{1 to} 3 ₄ are connected to the master 5 as the monitoring device main body via the master side signal line 4, respectively. Also, each separating / coupling device 3 _{1 to} 3 ₄
Is connected to a repeater 7 via a bus 6, and the repeater 7 is connected to a personal computer 9 as a sensor control device via a transmission line 8.

Here, the sensors with communication function 1 ₁ to 1 ₁₆ are
DC4 which detects process quantity and corresponds to this process quantity
The process amount detection signal, which is an analog signal of ˜20 mA, is sent to the master 5 via the separating / combining units 3 _{1 to} 3 ₄ .

The master 5 monitors the process based on the process amount when subjected to process variable detection signals sent from the communication function equipped sensors 1 ₁ to 1 _16, and outputs a process variable corresponding to the detection signal . The master 5 is an existing monitoring device main body that does not have a communication function for the sensors with communication function 1 ₁ to 1 ₁₆ . On the other hand, the personal computer 9 sends an information request command signal to the repeater 7 in response to an external operation or a predetermined program.

The repeater 7 sends the information request command signal received from the personal computer 9 to the corresponding decoupling couplers 3 _{1 to} 3 ₄ via the bus 6 by switching the connection of the bus 6 based on the content thereof. .

The decouplers 3 _{1 to} 3 ₄ superimpose the information request command signal received from the personal computer 9 on the process amount detection signal. The information request command signal is a digital signal.

When the sensors with communication function 1 ₁ to 1 ₁₆ receive the information request command signal superposed on the process amount detection signal by the decouplers 3 _{1 to} 3 _4, they execute the process corresponding to the command signal. together, and it sends superimposes the detection information response signal corresponding to the processing process variable data information superimposed signal to the separator coupler 3 ₁ to 3 _4. The detection information response signal is a digital signal and represents the measurement range of the sensor, for example. The separating / combining devices 3 _{1 to} 3 ₄ extract the detection information response signal from the information superimposition signal sent from the sensors with communication function 1 ₁ to 1 ₁₆ and send it to the bus. Repeater 7
Receives the detection information response signal on the bus 6 and serially transmits the response signal via the transmission line 8 to the personal computer 9
Send to. The personal computer 9 outputs the detection information based on the detection information response signal received from the repeater 7. Next, the configurations of the repeater 7 and the separating / combining units 3 _{1 to} 3 ₄ will be described with reference to the drawings. FIG. 2 is a block diagram showing the configurations of the repeater and the separating / combining unit.

This repeater 7 is an RS232C interface 11 connected from a personal computer 9 via a transmission line 8.
However, UART 12 on the personal computer side, internal bus 13, U on the bus side
It is connected to the bus 6 via the ART 14, the modem 15 and the multiplexer 16. The internal bus 13 is connected to a CPU 17 which switches the bus 6 by controlling the multiplexer 16 based on the content of the information request command signal.

Here, the bus 6 includes four common lines C1 to C4 corresponding to four separate couplers and four common lines C4 to C4 connected to one separate coupler. The common lines C1 to C are composed of distribution lines D1 to D4.
The repeater 7 is connected to a separate coupler corresponding to a desired sensor with a communication function by a combination of 4 and distribution lines D1 to D4.

The decoupling couplers 3 _{1 to} 3 ₄ are composed of four sensor connection parts 21 and one bus connection part 22.
Since each of the separating / coupling devices 3 _{1 to} 3 ₄ and the four sensor connecting portions 21 thereof have the same configuration, one sensor connecting portion 21 of one separating / coupling device 3 ₁ will be described as an example here.

The sensor connecting portion 21 includes a resistor 23 and a DC 24.
Power capacitor 24 V is applied, it has a transformer 27 and a capacitor 28 consisting of the sensor side and the bus side windings 25 and 26, the sensor-side signal line 2 sensor 1 ₁ with a communication function via a resistor 23, power supply The capacitor 24 is connected so as to form a loop. Further, a master side signal line 4 is connected to both ends of the resistor 24 so as to detect a process amount detection signal, and a series circuit of a sensor side winding 25 of a transformer 27 and a capacitor 28 is connected. The transformer 27 extracts the detection information response signal from the information superposition signal and sends it to the bus 6, and superimposes the information request command signal received from the bus 6 on the process amount detection signal.

Here, one end 26a of the bus side winding 26 of the transformer 27 is connected to one of the bus common lines C1 to C4 corresponding to each of the separating and coupling devices 3 _{1 to} 3 _4. , Here, it is connected to the common line C1. Further, the other end 26b of the bus-side winding 26 is connected to one of the distribution lines D1~D4 bus 6 for each sensor connection portion 21 of the separator coupler 3 _1. Next, the operation of the monitoring device thus configured will be described. Now, the information request command signal is sent from the personal computer 9 to the repeater 7 by the operation of the operator.

In the repeater 7, the CP is transmitted via the RS232C interface 11 and the personal computer side UART 12.
U17 receives the information request command signal. CPU17
Controls the multiplexer 16 based on the transmission destination of the information request command signal to switch the connection of the bus 6 to, for example, the separation repeater 3 ₁ and its sensor connection portion 21. Then, the CPU 17 sends the information request command signal to the bus 6. The information request command signal is sent via the bus 6 to the separate coupler 3
₁ and is superimposed on the process amount detection signal via the transformer 27.

When the sensor with communication function 1 ₁ receives the information request command signal superimposed on the process amount detection signal, it executes a process based on this information request command signal, and the detected information response signal corresponding to this process. Is superposed on the process amount detection signal and an information superposition signal is transmitted. A detection information response signal is extracted from the information superposition signal by the transformer 27, and the detection information response signal is sent to the repeater 7 via the bus 6.

In the repeater 7, the CPU 17 receives the detection information response signal via the modem 15 and the bus side UART 14, and sends the detection information response signal to the personal computer side U.
It is transmitted to the personal computer 9 via the ART 12 and the RS232C interface 11. The personal computer 9 displays and outputs the detection information based on the transmitted detection information response signal.

As described above, according to the first embodiment,
Sending an information request command signal transmitted from the personal computer 9 to the repeater 7 and separator coupler 3 ₁ by the process amount detecting signal sensor with a communication function is superimposed on 1 _1. When the detection information response signal extracted by the separating / combining device 3 ₁ from the information superimposition signal transmitted by the sensor with communication function ₁ is transmitted to the personal computer 9 by the repeater 7, the personal computer detects based on the detection information response signal. Output information.

Therefore, it is possible to communicate with the sensor with a communication function without interrupting the process amount detection signal of the sensor by using the conventional master as the main body of the monitoring device as it is. Also, when communicating with other sensors with communication functions, it is possible to communicate without changing the connection simply by changing the transmission destination of the information request command signal, so the process monitoring accuracy for plant equipment is greatly improved. be able to.

Furthermore, since the sensors with communication function 1 ₁ to 1 ₁₆ are connected to the bus by adding a separate coupler,
Since the sensor with the communication function can be easily added, the expandability of the process can be improved.

Further, in the first embodiment, the coupling / separating device superimposes the information request command signal, which is a digital signal, on the process amount detection signal, which is an analog signal of DC 4 to 20 mA, and outputs the detection information response signal. Since it is extracted, it can be easily applied to the currently practical equipment.

Further, in the first embodiment, the personal computer 9, the repeater 7 and the separating / coupling devices 3 _{1 to} 3 ₄ are added to the existing master 5, so that the master 5 has a communication function. It is possible to realize the communication function for the sensor with the communication function at a low cost as compared with the case of replacement. Further, the maintenance / inspection work for each sensor can be simplified by communicating with the sensor with a communication function. Next, a monitoring device according to the second embodiment of the present invention will be described.

FIG. 3 is a circuit diagram showing a modified example of the sensor connection portion in this monitoring apparatus. The same parts as those in FIG. 2 are designated by the same reference numerals and detailed description thereof will be omitted, and only different parts will be described here. .

That is, the sensor connecting portion 29 shown in FIG.
In addition to the sensor connection portion 21 shown in FIG. 2, one end of the sensor with communication function is connectable between the resistor 23 and the power supply capacitor 24, and the other end of the sensor with communication function is connected to the resistor 23. Thus, the circuit is configured so that the sensor with the communication function and the resistor 23 can form a loop.

Here, the sensor with communication function can be connected so as to form a loop including the sensor with communication function and the resistor 23 and the power supply capacitor 24, and only the sensor with communication function and the resistor 23 can be connected. It can also be connected to form a containing loop. Therefore, in the case of a two-wire type sensor with a communication function, the sensor with a communication function, the resistor 23 and the power supply capacitor 24 are connected so as to form a loop. It suffices to connect only the resistor 23 so as to form a loop.
When the connection of the sensor with communication function is completed, the monitoring device can be operated as described above by sending the information request command signal from the personal computer 9.

As described above, according to the second embodiment,
When connecting the sensor with communication function to the sensor connection part, the loop including the sensor with communication function and the resistor and the loop including the sensor with communication function, the capacitor and the resistor can be selected. A sensor with a communication function can be arbitrarily selected and connected, and the variability and expandability of the system can be further improved.

In the first embodiment, the personal computer 9
Information request command signal sent from the superimposed process amount detection signal has been described to be applied to the communication function equipped sensor 1 _1, it is not limited to this, for setting change detection information of the communication function equipped sensor 1 ₁ to, the information setting command commands to set the detection information sent from the personal computer 9, even when providing the information setting command signal superimposed on the communication function equipped sensors 1 ₁ to process variable detection signals, the present invention the same effect as Can be obtained.

In the first embodiment, the case where the digital signal is superimposed and extracted on the analog signal has been described, but the present invention is not limited to this, and the sensor with a communication function for transmitting the process amount detection signal as a digital signal. Is installed,
Even if the digital signal is superimposed and extracted with respect to the digital signal, the present invention can be similarly implemented and the same effect can be obtained.

Further, in the first embodiment, the case where the information request command signal is sent from the personal computer 9 in response to the operation from the outside has been described, but the present invention is not limited to this, and the information request is made based on a predetermined program. Even if the command signal is transmitted, the same effects can be obtained by implementing the present invention in the same manner. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0041]

As described above, according to the present invention, in the signal path of the detection signal from the sensor with the communication function to the main body of the monitoring device, the separation for modulating and demodulating each control signal of command and response to this detection signal. By inserting the coupler, the conventional monitoring device itself can be used as it is, the sensor with communication function can be remotely controlled, and various information other than the detection signal of the sensor with communication function can be collected. It is possible to provide a monitoring device capable of significantly improving the process monitoring accuracy of equipment and simplifying the inspection and maintenance work for each sensor.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a monitoring device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a repeater and a separating / combining device in the embodiment.

FIG. 3 is a circuit diagram of a sensor connection unit used in the monitoring device according to the second embodiment of the present invention.

[Explanation of symbols]

1 ₁ to 1 ₁₆ ... Sensor with communication function, 2 ... Sensor side signal line,
3 _{1 to} 3 ₄ ... Separation coupler, 4 ... Master side signal line, 5 ... Master, 6 ... Bus, 7 ... Repeater, 8 ... Transmission line, 9 ... Personal computer.

Claims (2)

[Claims] 1. A monitoring device body for monitoring a process state of plant equipment, a process amount in the plant equipment, a detection signal corresponding to the detected amount, sent to the monitoring device body, and superimposed on the detection signal. A sensor having a communication function for extracting the command signal thus generated, performing a process corresponding to the command signal, and transmitting a response signal by superimposing the response signal on the detection signal; A separating / combining device which is inserted in a signal path of a detecting signal, extracts a response signal superimposed on the detecting signal, and superimposes a command signal on the detecting signal, and the communication function is provided via the separating / combining device. A sensor for controlling a process amount detection operation in the sensor with communication function by sending a command signal to the sensor and receiving a response signal from the sensor with communication function. A monitoring device comprising: a controller. 2. The separation / coupling device superimposes / extracts the command signal and the response signal, which are digital signals, on the detection signal, which is an analog signal of DC 4 to 20 mA. Monitoring equipment.