JP2010161707A - Remote monitoring and control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a remote monitoring and control system adaptable to various input signals. <P>SOLUTION: An interface circuit 300 includes: rectification means 331, 332 for rectifying a signal applied between input terminals 301 and 302; a constant voltage means 343 for dropping an output signal from the rectification means 331, 332 to a constant voltage; and detection means 351, 352, 361 for detecting the signal dropped into the constant voltage by the constant voltage means 343 and transferring the signal to a control circuit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a remote monitoring and control device that remotely monitors and controls devices via a wireless packet communication network.

  In recent years, telemetry for collecting information and the like via a wireless packet communication network has become widespread. Telemetering was originally a general term for a mechanism for reading out the measurement value of a measuring instrument using a communication line. However, in recent years, the term is generally used not only for reading data but also for monitoring the operation of devices and for remote control. Representative examples of telemetering include a vending machine sales management system, a gas / water usage management system, an operation monitoring system for various equipment such as boilers, and an unmanned parking management system. In such a field of telemetering, a remote monitoring control device is provided in parallel with a monitoring target or control target device. Patent Document 1 describes an example of a remote monitoring control device. The remote monitoring and control apparatus described in Patent Document 1 is used as a system for monitoring the supply amount of gas, and a pressure transmitter for generating monitoring data is connected to the remote monitoring and control apparatus. . This pressure transmitter is a device that detects the secondary pressure of the governor that adjusts the gas supply pressure. The pressure transmitter is supplied with DC 24V from the remote monitoring control device, and analog data corresponding to the detected pressure is input to the remote monitoring control device.

JP-A-6-141369

  However, the remote monitoring and control apparatus has a problem that it cannot be applied to other systems because it is an apparatus specialized for monitoring the gas supply amount. That is, the input signal to the remote monitoring control device requires power supply from the remote monitoring control device when the connected device is a sensor or the like as described above, but the required specifications of the power supply vary depending on the device. . Further, the input signal to the remote monitoring control device may be an AC signal or a DC signal, and the maximum voltage and the like are various. In order to correspond to such various input signal specifications, it is conceivable to provide input terminals according to each specification. However, in this case, the number of input terminals increases, and it is difficult to reduce the size of the equipment or input channels. There were problems such as the need to reduce the number.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a remote monitoring and control apparatus that can handle various input signals.

  To achieve the above object, the present invention provides a communication module for connection to a wireless packet communication network, a control circuit that performs communication processing using the communication module and monitoring processing for a monitoring target, the control circuit and the monitoring circuit Rectification for rectifying a signal applied between a first and a second terminal and a first and a second terminal for inputting a signal from the monitored object in a remote monitoring and control apparatus having an interface circuit with the object Means, a constant voltage converting means for dropping the output signal of the rectifying means to a constant voltage, and a detecting means for detecting the signal converted to a constant voltage by the constant voltage converting means and transmitting it to the control circuit. Features.

  According to the present invention, when the input signal is alternating current, it is converted into a direct current signal by the rectifying means. When the input signal is a direct current, the rectifying means passes as it is. The DC signal is converted to a constant voltage by the constant voltage converting means and detected by the detecting means. Therefore, even if the input signal input between the first and second terminals is AC or DC, signal detection is possible even if the input signal is a high voltage.

  Further, the present invention relates to the remote monitoring and control apparatus, wherein the third terminal connected to the ground and the connection destination of one input line of the detection means are connected to one output line of the constant voltage means or the DC power supply. And switching means for switching to any one of them.

  According to the present invention, a device such as a sensor that requires a power source is provided between either the first or second terminal connected to one output line of the constant voltage means and the third terminal. Connect and monitor. That is, by connecting the connection destination of one input line of the detection unit to the DC power source by the switching unit, a current from the DC power source flows in the detection unit according to the resistance value / conduction state of the sensors. Therefore, the detection means can monitor the device by detecting the current.

  Note that examples of the constant voltage means include a shunt regulator. Further, as the rectifying means, for example, a first diode connected from the first input terminal to one of the input line directions of the constant voltage forming means as a forward direction, and a second diode from the other input line of the constant voltage forming means. And a second diode connected with the input terminal direction as the forward direction.

  As described above, according to the present invention, an AC signal and a DC signal can be detected by a common terminal (first and second terminals), so that the apparatus can be downsized and the number of channels can be reduced at a low cost. can do. Furthermore, according to the present invention, since sensors that require power supply can be connected using one of the first and second terminals and the third terminal, the apparatus can be downsized and the number of channels can be reduced. Can be realized.

Perspective view of remote monitoring and control device with lid removed Functional block diagram of remote monitoring and control device Circuit diagram of interface circuit Side view of remote monitoring and control device Top view of interface circuit

  A remote monitoring control apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the remote monitoring control apparatus with the lid removed, and FIG. 2 is a functional block diagram of the remote monitoring control apparatus.

  As shown in FIG. 1, a remote monitoring control apparatus 1 according to the present embodiment includes a box-shaped first casing 100 and a box-shaped second casing attached to the upper surface of the first casing 100. The body 200 is provided. The first housing 100 has an inclined surface extending from the thin box-shaped upper surface to the edge. The first casing 100 includes a casing main body 110 that opens from a part of the upper surface to the inclined surface and a side surface (front surface) adjacent to the inclined surface, and a lid 120 that closes the opening of the main body 110. It has. The housing body 110 includes a partition plate 111 extending from the edge of the top opening to the bottom surface. In addition, a through hole 112 for passing wiring is formed on the side surface of the housing main body 110. A grommet 113 is attached to the through hole 112.

  As shown in FIG. 2, the remote monitoring control device 1 includes a communication module 10 for connecting to a wireless packet communication network, and a control for performing communication processing using the communication module 10 and monitoring processing and control processing of a monitoring target device. A circuit 20 and an interface circuit 300 with a monitoring target device are provided. The control circuit 20 is mounted on a circuit board (not shown) disposed in the second casing 200. The communication module 10 is also disposed in the second housing 200. On the other hand, the interface circuit 300 is mounted on a circuit board 150 disposed in the first housing 100. A circuit board (not shown) arranged in the second casing 200 and a circuit board 150 arranged in the first casing 100 are cables (not shown) arranged in a passage formed between the casings. ).

  FIG. 3 shows a circuit diagram of the interface circuit 300. In the present embodiment, the interface circuit 300 has eight input channels, but only one input channel will be described here for the sake of simplicity.

  The interface circuit 300 is designed to input various monitoring data. Specifically, it is possible to input an AC signal and a DC signal output from the monitoring target device or sensors attached to the device. In this embodiment, AC 100 to 200 V and DC 12 to 24 V can be input. In addition, it is possible to cope with the case where it is necessary to supply power for the monitoring target device or the sensors attached to the device to output monitoring data. For example, there are cases where the sensors are switching elements or elements whose resistance values change. Hereinafter, the interface circuit 300 will be described in more detail.

  The interface circuit 300 includes three input terminals 301, 302, and 303. Here, when an AC signal or a DC signal is monitored, an input terminal 301 and an input terminal 302 are used. When monitoring a DC signal, the input terminal 301 is a positive electrode and the input terminal 302 is a negative electrode. On the other hand, when power supply is required, the input terminal 302 and the input terminal 303 are used.

  The input terminal 303 is grounded via the fuse 312. The input terminal 301 is connected to one terminal of a circuit protection varistor 313 via a fuse 311. The other terminal of the varistor 313 is connected to the input terminal 302. One terminal (input terminal 301 side) of the varistor 313 is connected to the third terminal 323 of the jumper switch 320. A DC power source (DC 12 V in this embodiment) is connected to the first terminal 321 of the jumper switch 320. The jumper switch 320 short-circuits the second terminal 322 and the third terminal 323 using a jumper pin (not shown) when monitoring an AC signal or a DC signal. On the other hand, when power supply is required, the first terminal 321 and the second terminal 322 are short-circuited using a jumper pin.

  The second terminal 322 of the jumper switch 320 is connected to the anode of a diode 331 that is a rectifying element. The other terminal (input terminal 302 side) of the varistor 313 is connected to the cathode of a diode 332 that is a rectifying element. The cathode of the diode 331 is connected to the cathode of the shunt regulator 343 via two resistors 341 and 342 for current limiting. The shunt regulator 343 is for constant voltage, the reference terminal is connected to the cathode, and the anode is connected to the anode of the diode 332 to the cathode. A capacitor 344 and a resistor 345 are connected between the cathode and the anode of the shunt regulator 343, and NPN transistors 351 and 352 connected in a Darlington connection are connected. The emitter of the transistor 352 is connected to the resistor 345 through a resistor 353. The collectors of the transistors 351 and 352 are connected to the cathode of the photocoupler 361. The anode of the photocoupler 361 is connected to the cathode of the diode 331. The light receiving element side of the photocoupler 361 is connected to the control circuit 20.

  Next, the operation of the interface circuit 300 will be described. First, a case where an AC signal or a DC signal is monitored will be described. The AC signal applied between the input terminal 301 and the input terminal 302 is rectified by the diodes 331 and 332. A direct current signal applied between the input terminal 301 and the input terminal 302 flows in the subsequent stage as it flows in the forward direction with respect to the diodes 331 and 332. The rectified DC signal is subjected to voltage drop by resistors 341 and 342, and is further made constant voltage by a shunt regulator 342 to drive the transistors 351 and 352. Then, the photocoupler 361 is driven by the operation of the transistors 351 and 352. As a result, the input signal is transmitted to the control circuit 20.

  Next, a case where power supply is required will be described. In this case, the first terminal 321 and the second terminal 322 of the jumper switch 320 are short-circuited by a jumper pin, and DC power is supplied to the input terminal 302 via circuits such as resistors 342 and 342 and transistors 351 and 352. . Since a sensor, a switch element, or the like is connected between the input terminals 302 and 303, and the input terminal 303 is grounded, the transistors 351 and 352 operate according to the state of the sensor or the like. Since the photocoupler 361 is driven by the operation of the transistors 351 and 352, the status of the sensor or the like is transmitted to the control circuit 20 as an input signal.

  A method of mounting the interface circuit 300 will be described with reference to FIG. 1, FIG. 4, and FIG. FIG. 4 is a side sectional view of the remote monitoring and control apparatus 1 and FIG. 5 is a top view of the interface circuit 300. For the sake of simplicity, only the characteristic points of the present invention will be described here.

  The interface circuit 300 is mounted on the circuit board 150. The circuit board 150 has a rectangular shape that is slightly smaller than the bottom surface of the housing body 110 of the first housing 100, and is attached to the bottom surface of the housing body 110 via a spacer. A plurality of terminal blocks 151 are mounted on the edge of the circuit board 150 on the opening side. Each terminal block 151 has a plurality of terminals, and each terminal corresponds to the input terminals 301 to 303. A jumper switch 320 is disposed in the vicinity of the terminal block 151 and on the partition plate 111 side. Further, resistors 341 and 342 and transistors 351 and 352 are mounted behind the jumper switch 320. What should be noted here is that the resistors 341 and 342 and the transistors 351 and 352 are arranged on the side opposite to the opening of the housing body 110 with the partition plate 11 interposed therebetween. In other words, the terminal block 151 and the jumper switch 320 are exposed from the opening of the housing body 110, but the resistors 341 and 342 and the transistors 351 and 352 that are heat generating components are separated from the opening by the partition plate 111. It is hidden. Accordingly, it is possible to prevent the operator from touching the heat-generating component when connecting the wiring to the terminal block 151 or operating the jumper switch 320.

  As described above, according to the remote monitoring control device 1 according to the present invention, three input terminals are provided for each input channel, and a jumper pin is provided between the second terminal 322 and the third terminal 323 of the jumper switch 320. By short-circuiting, an AC output or DC output monitoring target device can be connected between the input terminal 301 and the input terminal 302. On the other hand, the first terminal 321 and the second terminal 322 of the jumper switch 320 are short-circuited by a jumper pin, so that a monitoring target device that requires a DC power source such as a sensor is connected between the input terminal 302 and the input terminal 303. It becomes possible. As described above, according to the remote monitoring and control apparatus 1 according to the present invention, various signals can be input through one input channel, so that downsizing and multi-channeling of the apparatus can be realized at low cost.

  Further, according to the remote monitoring and control device 1 according to the present invention, it is possible to prevent the operator from touching the heat-generating parts such as resistors and transistors during the wiring work to the terminal block 151 and the operation of the jumper switch 320. Excellent in properties.

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this. For example, in the above embodiment, the rectifier circuit includes a pair of diodes 331 and 332, the voltage regulator circuit includes a shunt regulator 343, and the detection circuit is implemented by a circuit including transistors 351 and 352 and a photocoupler 361. The present invention can also be implemented by this circuit configuration.

  DESCRIPTION OF SYMBOLS 10 ... Communication module, 20 ... Control circuit, 100 ... 1st housing | casing, 110 ... Housing | casing main body, 120 ... Cover, 150 ... Circuit board, 151 ... Terminal block, 200 ... 2nd housing | casing, 300 ... Interface Circuit, 320 ... Jumper switch, 331, 332 ... Diode, 341, 342 ... Resistor, 343 ... Shunt regulator, 351, 352 ... Transistor, 361 ... Photocoupler.

Claims (4)

Remote monitoring comprising a communication module for connection to a wireless packet communication network, a control circuit for performing communication processing using the communication module and monitoring processing for a monitoring target, and an interface circuit for the control circuit and the monitoring target In the control device,
First and second terminals for inputting signals from the monitoring target;
Rectifying means for rectifying a signal applied between the first and second terminals;
Constant voltage means for dropping the output signal of the rectifier means to a constant voltage;
A remote monitoring and control apparatus comprising: a detecting unit that detects a signal that has been converted to a constant voltage by a constant voltage generating unit and transmits the signal to the control circuit. A third terminal connected to ground;
The remote monitoring control device according to claim 1, further comprising a switching unit that switches a connection destination of one input line of the detection unit to one of the output line of the constant voltage conversion unit or the DC power source. . The remote monitoring control device according to claim 1, wherein the constant voltage converting unit includes a shunt regulator. The rectifying means has a first diode connected from the first input terminal to the one input line direction of the constant voltage converting means as a forward direction, and a second input terminal direction from the other input line of the constant voltage converting means. The remote monitoring control device according to claim 1, further comprising a second diode connected as a forward direction.

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