JP4569832B2 - Network power supply monitoring system - Google Patents

Description

The present invention relates to network power supply monitoring system.

  As is well known, in factory automation (hereinafter referred to as “FA”), an I / O device is connected to a programmable controller (hereinafter referred to as “PLC”) directly or via a network. The PLC acquires information from an input device such as a switch or a sensor that is a kind of the I / O device as input data, and executes arithmetic processing using the acquired input data in accordance with a user program incorporated in advance. The control content of the output system, which is a kind of I / O device, is determined, and control data corresponding to the control content is output to output devices such as valves, actuators, and motors to control the entire FA system. It is like that.

  More specifically, the control in the CPU unit of the PLC takes in the signal input from the input device connected to the input unit into the I / O memory of the CPU unit (IN refresh), and is built in a ladder language registered in advance. Performs logical operation based on the user program (operation execution), writes the operation execution result to the I / O memory and sends it to the output unit (OUT refresh), and the output unit performs control to drive and stop the output device. Thereafter, so-called peripheral processing such as communication processing is performed via the communication network. In this way, the PLC cyclically repeats IN refresh, operation execution, OUT refresh, and peripheral processing.

  Such a PLC is composed of a plurality of units. That is, a power supply unit of a power supply source, a CPU unit that controls the entire PLC, an output unit that inputs a switch or sensor signal attached to an appropriate place in an FA production device or facility device, an output that outputs a control output Various units such as a unit, an input / output unit having both input and output, and a communication unit for connecting to a communication network are appropriately combined.

  Furthermore, a network system called remote I / O is known. In this system, a master unit is connected to a PLC, and a slave is connected to the master unit via a device net (registered trademark) or the like.

  The slave includes an IN slave that takes in an input signal, an OUT slave that outputs an output signal, a Mix slave that inputs and outputs, and is referred to as a slave here. And a sensor, a relay, and various other devices are connected to the slave terminal. The master unit is one of the units constituting the PLC as described above, and is incorporated in the PLC. Thereby, for example, sensing information detected by an input device (switch, sensor, etc.) connected to the slave is taken into the PLC by serial communication to the master unit via the field network. On the PLC side, the user program is executed based on the acquired sensing information, and the execution result is transmitted as a control command signal to the slave via the master unit via the network, and the output device to be operated from the slave ( Control commands are sent to relays, valves, actuators, etc.

  In addition, transmission / reception of I / O information such as input signals and output signals of devices connected to the slave is performed at a communication timing set in advance between the slave and the master unit, and is asynchronous with the cyclic processing of the PLC. And it is operating at a different timing. The CPU unit of the PLC and the master unit are connected via a bus, and the cyclic processing in the CPU unit can be used to transfer data to and from the master unit using IN refresh, OUT refresh (I / O refresh), or peripheral service processing. Sending and receiving are done. Thereby, the CPU unit of the PLC can connect the input or output device arranged remotely to the slave and transmit / receive data via the network.

  By the way, in recent network systems, in addition to managing and monitoring current control contents, there is an increasing demand for monitoring and monitoring non-control information such as maintenance information, system status information, and maintenance information as appropriate. ing. In the conventional network system, since input data and output data including remote I / O exist in the memory of the PLC, all maintenance information is acquired in a program on the PLC side. For example, it can be obtained by measuring the time required for the operation time of the device connected to the slave and the I / O information to change to a different state. In order to perform such processing, a user creates a user program that performs the measurement, and the program is executed by the CPU unit of the PLC.

  However, when trying to obtain maintenance information on the PLC side in this way, two problems arise. First, the load of PLC program execution processing increases. This is because a burden of executing a program for acquiring maintenance information is generated. Second, the communication load between the master and slave increases. Since it is necessary to always obtain the latest information from the slave, it is necessary to communicate basic data related to maintenance information in addition to control information as I / O data in the communication process between the master and slave of the PLC. Occurs. This increases the amount of communication information, increases the communication processing time, and increases the communication cycle between the master and the slave.

Therefore, an object of the present invention is to reduce the influence on the control system on the PLC side when obtaining maintenance system information. More specifically, to ensure non-control data, such as maintenance information on the slave, to measure the voltage Te slave meter, and the results can be monitored via a network, the control load on the PLC side compared with the conventional The purpose of this is to improve the convenience of the monitor.

  Next, a more specific network system will be described with reference to the drawings, and supplementary explanations for additional purposes will be given below. As shown in FIG. 1, a PLC unit 1 and a master unit 2 having a communication function are integrated, and the master unit 2 is connected to a field network 3 for transmitting and receiving control system data. A plurality of slaves 4a, 4b and 4c are connected to the field network 3.

  The slaves 4a, 4b, and 4c are connected to an input device 5a such as a sensor and an output device 5b such as a valve and a motor. In the illustrated example, the slave 4a is also referred to as an IN slave because only the input device 5a is connected, and the slave 4b is also referred to as an OUT slave because only the output device 5b is connected. Since the input device 5a and the output device 5b are connected, they may be referred to as Mix slaves. In the following description, when it is not necessary to make a distinction, the slave is simply referred to as “slave” and the reference numeral “4” is attached. In addition, when it is not necessary to distinguish between the input device 5a and the output device 5b, the device is simply referred to as a device, and a reference numeral “5” is given.

  In the network system having such a configuration, the network power supply device 6 is installed, and power is supplied from the network power supply device 6 to the plurality of slaves 4 via the field network 3. The power supply to the devices 5 connected to each slave 4 may be supplied via the slave 4 using the power supplied from the network power supply device 6 to the slave 4. .

  Further, the power supply source for the various devices 5 is not limited to the network power supply device 6 described above. For example, an input / output device power supply device 7 provided separately may be used. That is, the power output of the input / output device power supply device 7 is given to each slave 4, and power is supplied to the device 5 via the slave 4. In this case, the input / output device power supply device 7 is a power supply for the device 5, and power supply to the slave 4 is performed from the network power supply device 6.

  By the way, considering the power supply from the network power supply device 6 to each slave 4, each slave 4 is performed via the field network 3, but the resistance value of the cable constituting the network is not zero. Therefore, a voltage drop occurs in the field network 3. Therefore, the voltage actually applied to the slave 4 has a voltage drop from the output voltage in the network power supply device 6. Therefore, the voltage drop increases with respect to the slave 4 that is remote from the network power supply device 6, and there is a possibility that an appropriate power supply voltage that satisfies the regulations cannot be obtained by the transmission / reception circuit chip in the slave 4 or the MPU of the slave. is there.

  Therefore, in order to operate this system normally, for example, the length of the cable used for the field network 3 can be limited, but the voltage drop caused by turning on the device 5 connected to the slave 4 is also possible. The cable length cannot be determined assuming that Further, if the length of the cable is determined with a sufficient margin, there is a possibility that the cable cannot be wired at the site where the FA system is constructed because the length of the cable is insufficient.

  Therefore, in order to operate this FA system normally, it is necessary to actually construct the system in the field and to confirm that the power supply voltage supplied to each slave 4 is an appropriate voltage satisfying the standard. . However, in order to confirm whether or not the power supply voltage is appropriate, there was no method other than an operator going to the site and directly measuring the power supply voltage of each slave using a voltmeter or the like. Therefore, such work is not only very time consuming, but the installation location of the slave is sometimes difficult to measure, such as the back side of the apparatus, and is complicated.

  There was no means for monitoring the voltage value of the power supply voltage at each slave. For this reason, there is a disadvantage that the abnormality is noticed only when communication with the slave becomes impossible due to a voltage drop during operation.

  In addition, when the power supply source of the device 5 is the input / output device power supply device 7, the same problem as described above occurs. That is, there is a problem that the power supply state of the input / output device power supply device 7 cannot be known by the PLC 1 and the master unit 2 which are higher-level stations, and also by a monitor device and a configurator described later. Further, in the master unit 2 as a higher station, and in other words, the PLC unit 1, the following problems have occurred.

  When the bit data corresponding to the input signal from the input device 5a connected to the slave 4 received from the slave 4 via the field network 3 is 0, the input device 5a actually performs the OFF operation and the input signal Therefore, it is impossible to determine whether the input signal is 0 data as a neutral operation because there is no power supply to the input device 5a and the device itself becomes inoperable.

  When the bit data corresponding to the output signal to the output device 5b transmitted to the slave 4 via the field network 3 is 0, the output signal to the output device 5b is actually turned off and 0 data is output. Therefore, it is impossible to determine whether the output device 5b is stopped or whether the output device 5b itself is inoperable because there is no power supply to the output device 5b. For this reason, there is a problem that the reliability of the system is lowered.

  Furthermore, in order to solve the above-mentioned problem, for example, a message is periodically sent from the master unit 2 and the PLC unit 1 to the slave 4, and the presence or absence of a response from the slave 4 is determined. It is possible to determine whether or not power is being supplied. However, in order to perform such processing, determination processing accompanying message transmission and response reception is performed by the PLC, and there is a problem in that the control of the original device 5 is affected. Therefore, an object of the present invention is to reduce the influence on the control system on the PLC side when the power supply on the slave side of the remote I / O is obtained as maintenance information.

  On the other hand, another specific system configuration is shown in FIG. That is, the PLC unit 1 and the master unit 2 having a communication function are integrated, and the master unit 2 is connected to the field network 3. The field network 3 is connected to an OUT slave 4b and an IN slave 4a. The basic network configuration is the same as that shown in FIG.

  In this example, an actuator 8 serving as an output device 5b is connected to the OUT slave 4b. In this actuator 8, the OUT slave 4b that has received a control command (ON signal) from the PLC unit 1 turns on the I / O terminal (OUT terminal) to which the actuator 8 is connected, so that the moving body 8a Move forward.

  On the other hand, a sensor 9 as an input device 5a is connected to the IN slave 4a, and the operation of the actuator 8 is monitored by this sensor 9. That is, when the moving body 8a in the actuator 8 moves to a predetermined position (position indicated by a dotted line in the figure), the sensor 9 detects the moving body 8a and outputs a detection signal.

  Since the detection signal is given to the IN slave 4a, the IN slave 4a has received the detection signal toward the PLC unit 1 (a predetermined I / O terminal (IN terminal) has been turned ON: an operation completion notification). Is output. Thereby, the PLC unit 1 knows that the actuator 8 has moved a predetermined amount, and therefore sends a stop command (origin return command) to the OUT slave 4b.

  In order to actually perform the above processing, each of the slaves 4a and 4b performs master-slave communication with the master unit 2 and transmits / receives each signal (data) described above. Therefore, the PLC unit 1 communicates with each of the slaves 4a and 4b via the master unit 2.

  Furthermore, the PLC unit 1 executes processing cyclically according to the user program, and IN / OUT refresh processing is performed for each cycle. At that time, a signal is output to the OUT slave 4b, Receive a signal from the IN slave 4a. On the other hand, in the master-slave communication, communication is performed with a predetermined slave at its own timing (communication cycle) asynchronously with the cyclic processing on the PLC unit 1 side.

  By the way, there is a request to monitor the operation time of the actuator 8, that is, the time during which the moving body 8a is moving. This is because, for example, the operation time and the reference time can be compared to determine whether the actuator 8 is normal or to determine the life due to the deterioration of the operation of the actuator. However, conventionally, it is necessary to measure the time on the PLC unit 1 side based on the ON / OFF information acquired from the slaves 4a and 4b. A program for such monitoring is generated and incorporated in the user program of the PLC unit 1. Will be executed. In other words, the timer starts when the PLC unit 1 outputs an operation command (ON signal) to the OUT slave 4b, and when the IN terminal ON signal (operation completion notification) is received from the IN slave 4a, the timer To stop. Thus, when the timer value is acquired, the operation time is known.

  However, in this method, in order to obtain the operation time information as the maintenance information, it is necessary to perform the operation time measurement process in addition to the original device control process on the PLC side. The same can be said for monitoring the operation time of the input device. That is, for example, when there are two input devices (sensors) that monitor the state of a certain device, one device detects that the device is in a certain state, and then the other sensor detects another device. By monitoring the time (operation time) until it is detected that a certain state has been reached, it is possible to determine whether or not the apparatus is operating normally.

  However, it is an obstacle to high-speed control to add the arithmetic processing for obtaining the operation time as described above during the arithmetic processing performed cyclically on the PLC unit 1 side for the control of the entire FA system. It becomes. In addition, as the number of devices to be processed increases, more processing is required to calculate the operation time on the PLC unit 1 side, which causes a problem that processing addition on the PLC side increases. In other words, as described above, the PLC unit 1 cyclically calculates the operation time every time to obtain the operation time, and wasteful processing is performed.

(1) To achieve the above object, a network power supply monitoring system according to the present invention includes a programmable controller that executes a user program for controlling a control device, and a master unit that is connected to the programmable controller and has a communication function. A plurality of slaves connected to the control unit and serially communicating IN data or OUT data with the master unit via the network, a network configurator connected to the network between the master unit and the slave, and a network A network power supply monitoring system in a network system for supplying power from the network power supply device to the slave through the network, wherein at least one of the plurality of slaves One slave, a slave to satisfy the following requirements.
The requirements are voltage monitoring means for measuring the supply voltage of the network power supply, measurement values measured by the voltage monitoring means, and criteria for determining whether or not the slave itself is likely to operate but become inoperable. A determination unit that outputs an alarm status when the measured value falls below the reference value, an alarm status storage unit that stores an alarm status output by the determination unit, and the alarm status storage unit Communication control means for outputting the alarm status stored in the network configurator via a network, and storage means for storing at least one of the maximum value / minimum value / current value of the measured value measured by the voltage monitoring means (In the embodiment, a maximum value / minimum value holding unit 33b, a current value storage unit 33c), and information on measured values stored in the storage unit. When, the reference value, in which a function of outputting to the network configurator via the network.
The network configurator is configured to display the alarm status, the measured value information, and the reference value acquired from the slave that satisfies the above requirements.

( 2 ) The display in the network configurator may display at least the information on the measured value on a graph and display the reference value on the graph.

Furthermore, the output timing can be configured to be output in accordance with the internal trigger such as the determination result in the slave, power-up, transmission timer, and the like. Of course, it may be based on an external trigger.

Here, the “internal trigger” is based on the result of execution of a predetermined process of the slave itself, and is generated inside the slave. An example of the internal trigger is as follows. That is, if it is determined whether the measurement value measured by the slave is below the reference value, the determination result is generated. Some use the generated signal as a trigger signal. In addition, when the slave is turned on to perform initial processing, information stored in the nonvolatile memory may be output to the line during the initial processing, or a trigger may be generated during the initial processing. Further, there is a slave that has a clock and generates a trigger signal periodically every time a predetermined time elapses, or generates a trigger signal at a predetermined time. In addition, there is a type that generates a trigger signal when there is a margin in communication processing based on the state of communication traffic with the master, or generates a trigger signal when an abnormality such as voltage abnormality occurs.

  On the other hand, the “external trigger” is based on a command received by the slave via the network, and is generated outside the slave. As an example of an external trigger, an information request command from the master to the slave, an information request command from the monitor to the slave, an information request command from the configurator, a command sent via the PLC or the master via tool transmission and so on.

  Furthermore, in the network power supply monitoring system, a programmable controller that executes a user program for controlling a control device, a master unit that is connected to the programmable controller and has a communication function, a control device is connected, and Including a plurality of slaves that serially communicate IN data or OUT data via a network, a network configurator connected to a network between the master unit and the slave, and a network power supply device. A network power supply monitoring system in a network system that supplies power to the slave through the network is assumed. And at least one of the plurality of slaves is provided with power monitoring means for monitoring the state of the network power supplied from the network power supply device through the network, and the network configurator has the at least one slave and By communicating via the network, means for collecting the status of the slave network power source monitored by the power source monitoring means and means for centrally managing the status of the collected slave network power source are provided.

  Preferably, the power supply monitoring unit includes a voltage detection unit that sequentially detects a current value of the voltage of the network power supply, and a minimum value selection unit that selects a minimum value from the current values that are sequentially detected by the voltage detection unit. The current value detected by the voltage means and the minimum value selected by the minimum value selection means are collected via the network, and the collected current value of the network power supply voltage is the minimum value. It can also be configured to display a monitor together.

  In that case, the power supply monitoring means includes a monitoring voltage storage means for storing a desired monitoring voltage, and a monitoring voltage in which the current value of the network power supply voltage detected by the voltage detection means is stored in the monitoring voltage storage means. An alarm information storage means for storing the alarm information when it falls below, and the alarm information stored in the alarm information storage means is collected via the network to monitor the power supply alarm status of each slave be able to.

  Further, the power supply monitoring means includes a monitoring voltage storage means for storing a desired monitoring voltage, and a minimum value of the network power supply voltage detected by the minimum value selection means is lower than the monitoring voltage stored in the monitoring voltage storage means And alarm information storage means for storing alarm information, and the alarm information stored in the alarm information storage means is collected via the network so as to monitor the power supply alarm status of each slave. You can also.

  The network system monitoring method includes a programmable controller that executes a user program for controlling a control device, a master unit that is connected to the programmable controller and has a communication function, and a control device that is connected to the master unit. A monitoring method for a network system in which a plurality of slaves that serially communicate IN data or OUT data via a network and a monitor device are connected via the network. And while the said slave performs the process which communicates the input information or output information of the said control apparatus between the said controllers via the said network, the process which measures the physical quantity regarding the said control apparatus or the said slave itself, A process of comparing the measured measurement value and a reference value is performed, and the comparison result information is output to the network. At least one of the controller or the monitor performs a process of receiving the slave comparison result, and the received comparison result. A process to manage information was added.

  Each means constituting the slave, the node, and the processing device according to the present invention can be realized by a dedicated hardware circuit, or can be realized by a programmed computer.

  As described above, in the present invention, the measurement unit is provided, and the measurement unit measures the physical quantity of the control device and the slave regardless of the control, so that the control information is not affected and the control information is not controlled. Data (non-I / O data) can be secured by a slave, output to a line (network) at a predetermined timing, and notified to a predetermined transmission destination.

  FIG. 3 shows an example of a system configuration to which the present invention is applied. As shown in the figure, in the present embodiment, a PLC unit 10 and a master unit 11 having a communication function are integrated, and the master unit 11 is connected to a field network (remote line) 12. The PLC unit 10 and the master unit 11 are connected by a bus. The field network 12 is connected to a Mix slave 13 that can connect an input device and an output device.

  The PLC unit 10 is also called a CPU unit, and cyclically processes I / O refresh, program execution, and peripheral processing. In addition, although illustration is omitted, various units other than the PLC unit 10 are connected as necessary to configure the PLC, but the unit itself is a conventionally known unit, and thus description thereof is omitted. In addition, the master unit 11 performs master-slave communication with the Mix slave 13, and in response to a request from the master unit 11, the I / O data of the input device and the output device connected to the Mix slave 13 Send and receive. The I / O data exchange between the PLC unit 10 and the master unit 11 is performed by data communication via a bus as an I / O refresh process in a cyclic process performed by the PLC unit 10. Note that the master-slave communication described above is performed asynchronously with the cyclic processing of the PLC unit 10.

  The Mix slave 13 is a mixed type in which the functions of the OUT slave 4b and the IN slave 4a shown in FIG. 2 are incorporated. The actuator 14 is connected to the OUT terminal, and the moving body 14a of the actuator 14 is connected to the IN terminal. A sensor 15 for monitoring the position of is connected.

  An example of the internal structure of the Mix slave 13 is shown in FIG. That is, a transmission / reception circuit 13a connected to the field network 12 for transmitting / receiving data, an MPU 13b connected to the transmission / reception circuit 13a, an output circuit 13c connected to an output device, and an input circuit 13d connected to an input device. It has. Further, an external nonvolatile memory 13e, a timer (internal clock) 13f, and the like are provided.

  The transmission / reception circuit 13a receives the frame flowing on the field network 12, analyzes the header portion to determine whether the frame is addressed to itself, finally receives only the frame addressed to itself, and passes it to the MPU 13b. And a function of outputting a transmission frame (for example, a frame for transmitting IN data toward the master unit 11) given from the MPU 13b onto the field network 12.

  The MPU 13b performs a predetermined process according to information stored in the data portion of the received frame given from the transmission / reception circuit 13a. As a basic function, the MPU 13b performs an output circuit 13c according to the OUT data in the data portion. A control signal for turning on / off a predetermined OUT terminal is issued. Further, it has a function of acquiring the ON / OFF state of the input terminal via the input circuit 13d, generating a frame for transmitting the acquired information to the master unit 11 as IN data, and passing it to the transmission / reception circuit 13a.

  The operation control of the actuator 14 in the above-described system is performed by cyclically executing a user program mounted on the PLC unit 10 and turning on the OUT terminal of the Mix slave 13 when a predetermined condition is met. The master unit 11 transmits a predetermined frame (OUT data) to the corresponding Mix slave 13 according to the communication cycle.

  The Mix slave 13 turns ON the OUT terminal connected to the actuator 14 in accordance with the received frame (OUT data). Thereby, a valve (not shown) is turned on (opened), and the moving body 14a moves forward.

  On the other hand, as described in the conventional example, since the sensor 15 is installed alongside the actuator 14, when the moving body 14a moves to a predetermined position (movement completion position in the present embodiment), the sensor 15 is moved. Is ON, that is, the IN terminal to which the sensor 15 is connected is turned ON. Since the MPU 13b can acquire the fact that the IN terminal has been turned on via the input circuit 13d, the IN terminal is transmitted to the master unit 11 as IN data when the transmission timing of its own frame comes. Then, the master unit 11 passes the acquired IN data during the refresh process in the PLC unit 10.

  Since the above-described processes and the functions and configurations of the processing units for executing the processes are the same as those in the related art, detailed description thereof is omitted. Here, in the present invention, the function for measuring the operation time of the actuator described above is provided in the Mix slave 13.

  In other words, since the MPU 13b can recognize the state of the OUT terminal and IN terminal held by itself, for example, as shown in FIG. 5, the time t from when the predetermined OUT terminal is turned on until the IN terminal is turned on is set. Measurement is performed using a timer (internal clock) 13f, and the measurement result is stored in the internal volatile memory 13b '. Here, when the OUT terminal and the IN terminal are turned ON, a signal rise indicates the same state.

  Further, the Mix slave 13 also holds information regarding the normal operation time, and determines whether the measurement result is within the normal operation time and determines the state of the actuator 14 (not to mention the determination result, the internal (Stored in the volatile memory 13b '). The normal operation time described above may be set with one threshold value, for example, within 10 ms, or may be set with two threshold values, such as 90 ms to 100 ms. The set value for specifying the normal operation time is stored in the external nonvolatile memory 13e, and is expanded in the internal volatile memory 13b 'every time the power is turned on.

  Further, although not specifically shown, the table structure in which the combination of the OUT terminal and IN terminal numbers to be monitored and the set values described above are associated is stored in the external nonvolatile memory 13e. Such information is expanded in the internal volatile memory 13b '. The internal volatile memory 13b' has a table structure in which measurement results and determination results are actually stored in association with each other.

  Specifically, the processing unit 13b ″ of the MPU 13b executes the flowchart shown in FIG. 6. Note that the operation time t of the calculation target and the monitoring target is OUT as shown in FIG. Both the terminal and the IN terminal are changed from OFF (Low) to ON (High), that is, the rising edges of the signals are linked, and the time from the rising edge of the OUT signal to the rising edge of the IN signal is defined as an operation time t. It is premised on what to do.

  As shown in FIG. 6, first, it is determined whether or not the corresponding OUT terminal (in the case of FIG. 3, the OUT terminal to which the actuator 14 is connected) rises (when an ON signal is reached) (ST1).

  If the rising edge is detected, the start time (count value) at that time is acquired from the timer 13f (ST2). In this embodiment, the timer (counter) is used because it only measures the operation time. However, when acquiring the date and time data for which the operation time is measured, an internal clock may be used.

  Next, it is determined whether or not the corresponding IN terminal rises (when an ON signal is reached) (ST3). When the rising edge is detected (Yes in the branch determination in step 3), the value of the timer 13f (stop time) is acquired (ST4), the difference from the start time acquired in step 2 is obtained, and the operation time is calculated. The result is stored in the result buffer.

  On the other hand, a preset value that defines the normal actuator operation time is stored in advance, and the operation time calculated in step 5 is compared with the set value to determine whether it is within the range (normal). In addition, the result is stored in the result buffer (ST6).

  Then, when the above-described processing is repeatedly executed sequentially for the set monitoring target and the processing is executed for all the points (Yes in ST7), the obtained operation time and the comparison result are obtained for each monitoring target (actuator 14). Etc.) is stored and held in the internal volatile memory 13b '(ST8). Since such processing is executed according to the interrupt instruction, if the processing up to step 8 is executed, it waits for the next instruction.

  On the other hand, the stored operation time and the comparison result are, for example, that the master unit 11 outputs a message at a predetermined timing, and the Mix slave 13 that has received the message operates the target device (address) specified by the message. By returning the time or the like as a response to the message, the master unit 11 and thus the PLC unit 10 can be notified. As described above, when the message from the master unit 11 is used, the master unit 11 side is a communication independent of the transmission of the IO data, and can receive only necessary information to be monitored when necessary. .

  The notification of the operation time or the like is not limited to the response to the message described above, and can be transmitted by, for example, a polling process between the master and the slave. That is, each slave transmits IN data to the master unit 11 at a predetermined timing. Therefore, as shown in FIG. 7, a transmission frame is generated in which the data portion includes the IN data which is the state of the normal input terminal plus the operation result (operation time, comparison result, etc.) managed by the slave. And can be notified by sending. This method is preferable because the master unit 11 does not need to generate and transmit a message requesting acquisition of the operation time.

  As yet another method, Change of State that is operated mainly by the slave side can also be used. That is, the Mix slave 13 transmits the result to the master unit 11 only when there is a change in the operation time to be managed by itself or a comparison result. By adopting this method, unnecessary data does not flow on the field network 12, and the master unit 11 can receive the operation time only when necessary, so that traffic can be reduced.

  In the present embodiment, since the operation time is calculated and further the status determination process is executed on the slave side and stored, the cyclic processing in the PLC unit 10 as well as the communication cycle in the field network 12 is performed. Necessary information can be obtained without any influence. Moreover, since the operation time is calculated in the slave, it can be obtained even if the operation time is shorter than the processing time required for one cycle in the cyclic processing.

  FIG. 8 shows a second embodiment of the present invention. In this embodiment, the OUT slave 20 and the IN slave 21 are connected to the field network 12 instead of the Mix slave. Then, by performing peer-to-peer communication (slave-to-slave communication) between slaves, ON / OFF information of a desired OUT terminal is transmitted from the OUT slave 20 to a predetermined IN slave 21 (usually a slave to which the sensor 15 is connected). To give.

  Then, the processing unit of the MPU in the IN slave 21 executes processing similar to the flowchart shown in FIG. 6, and the OUT terminal is turned on based on the ON / OFF information of the OUT terminal received from the OUT slave 20. Start time and stop time when a predetermined IN terminal is turned on, and obtain an operation time from the difference between the start time and the set value, and hold the comparison result.

  For data transmission from the OUT slave 20 to the IN slave 21, for example, the node number of the corresponding OUT slave and the bit number of the OUT terminal are stored in advance in the IN slave 21, and the IN slave 21 is transmitted at a predetermined timing. However, it can be realized by inquiring the state of the bit number to the OUT slave 20 of the stored node number, and as a response to the inquiry, the OUT slave 20 notifies the ON / OFF state of the bit number.

  According to such a method, the OUT slave 20 only needs to respond to a transmission request, and therefore there is no need to store and hold information about the corresponding IN slave 21. Conversely, if the information about the corresponding IN slave is also stored in the OUT slave 20, for example, when the desired OUT terminal is turned ON, the ON information is notified to the corresponding IN slave 21. The IN slave 21 obtains the start time when the notification of the ON information is received, obtains the stop time when the IN terminal is turned on, calculates the operation time from both times, and sets the set value. The comparison result may be obtained.

  In order to store the information necessary for measuring the operation time in the IN slave 21 or the like, for example, using the tool device, the association data as shown in FIG. (MACID) and bit number ”,“ OUT slave node number (MACID) and bit number ”, and“ OUT monitoring time unit ”are created and related to the slave to be stored based on this table. This can be done by creating a message (see FIG. 10) containing information in the data part and sending it to the corresponding slave via the field network 12 via the tool device or master unit 11.

  The OUT monitoring time unit is a unit of time for monitoring the status of other slaves, and the status of the corresponding bit is inquired at the monitoring time interval. Therefore, the OUT monitoring time unit is the minimum unit of the operation time measurement function.

  FIGS. 9 and 10 illustrate the setting of the association between the OUT slave (OUT terminal) and the IN slave (IN terminal), but a function for comparing the operation time obtained on the slave side with the set value is added. In this case, it is preferable to transmit the setting values for comparison in association with each other.

  In the present embodiment, since the output device such as the actuator 14 to be monitored and the input device such as the sensor 15 are connected to different slaves, communication via the field network 12 is performed at least once. Regardless of the cyclic time of the user program in the PLC unit 10, it is caused only by the communication cycle, and the communication cycle is very short compared to the cyclic time. A value close to the actual operation time can be obtained.

  In the above-described embodiment, the operation time is calculated by the IN slave 21 to which the sensor 15 as the input device is connected. On the contrary, the IN slave 21 changes to the corresponding OUT slave 20. On the other hand, by sending ON / OFF information of the IN terminal, the operation time may be calculated and compared with the set value on the OUT slave 20 side.

  Furthermore, the calculation of the operation time is not necessarily limited to a slave to which an input device such as a sensor for monitoring the output device or an output device whose operation time is to be obtained, and may be another slave. In that case, the ON / OFF information of the OUT terminal and the ON / OFF information of the IN terminal are respectively acquired from the OUT slave 20 and the IN slave 21 and calculated.

  Furthermore, since the operation time and the like can be calculated even in the slave to which the input / output device is not connected in this way, by incorporating such a calculation function (function for executing the flowchart shown in FIG. 6) into the master unit 11, You may make it require in the master unit 11. Even in such a case, since it is not affected by the cyclic time of the user program in the PLC unit 10, it can be obtained with relatively high accuracy.

  In addition, when obtaining with the master unit 11, the ON / OFF information of the OUT terminal and IN terminal is obtained by inquiring the corresponding slave in the same manner as obtaining with the other slave, and by obtaining a response accompanying it. Alternatively, the corresponding slave side may be configured to notify the master unit 11 when a predetermined terminal is turned on, but the master unit 11 manages the transmission / reception of IO information. Can also be used. That is, the operation time can be calculated by acquiring the start time when transmitting the corresponding OUT data and acquiring the stop time when receiving the IN data.

  By the way, in each of the above-described embodiments and modifications, the example in which the period from when the output terminal is turned on (rising) to when the input terminal is turned on (rising) is obtained as the operation time is shown. Is not limited to this, and the period from when the output terminal changes to when the input terminal changes can be obtained as the operation time.

  That is, for example, as shown in FIG. 11, when an ON signal is given to the OUT terminal of the Mix slave 13 (or the OUT slave 20 is acceptable) to which the actuator (cylinder) 14 is connected, the valve opens and the moving body (cylinder) Head) 14a moves forward. In the example shown in FIG. 5, the movement completion position of the moving body 14a is detected by the sensor 15. However, in the example shown in FIG. 11, the sensor 15 'is positioned at the intermediate position X of the movement path of the moving body 14a. Consider a system in which the sensor 15 'detects that the moving body 14a has passed the intermediate position X and outputs a detection signal (the IN terminal of the Mix slave 13 is ON). Although the example applied to the Mix slave 13 is shown in the figure, it is needless to say that the present invention can be similarly applied to a system having a configuration in which the OUT slave 20 and the IN slave 21 are divided as in the second embodiment. .

  In this case, since the sensor 15 'has a certain detection area, the output signal of the sensor 15' (input signal to the IN terminal) is output when the moving body 14a reaches the intermediate position X (in the detection area of the sensor). Turns on (rises) when entering. Then, if the moving body 14a further moves forward as it is and is located outside the detection region, it is turned off (falls down).

  Therefore, the determination is made when the moving body 14a passes the intermediate position X. When the output signal of the sensor 15 'is turned on (rising of the IN terminal), and when the moving body 14a is turned from ON to OFF (the IN terminal is turned on). Any one of them can be taken, and which one is decided is determined by the use of the obtained operation time. And when calculating | requiring the operation time t accompanying the former rising, the operating time t can be calculated | required using each above-mentioned embodiment by making the rising of each signal associate (correlate).

  On the other hand, when determining the operation time t ′ associated with the latter falling, it is possible to deal with it by changing the branch determination in step 3 to the process of “whether the corresponding IN is ON → OFF” based on the flowchart shown in FIG. can do. This is an embodiment corresponding to OUT terminal: ON (rising) → IN terminal OFF (falling).

  Furthermore, in each of the embodiments and modifications described above, the start time of the operation time is triggered by the OUT terminal being turned on (rising), but the present invention is not limited to this, and the OUT terminal is turned off. What happens (falling) can also be a trigger.

  As an example, as shown in FIG. 11 described above, when the OUT terminal of the Mix slave 13 is turned ON and the valve is turned ON, gas or fluid flows along with it, and the moving body 14a moves forward. When the valve is turned OFF and the valve is also turned OFF, there is a type of cylinder in which the moving body 14a moves backward and automatically returns to the original position. Therefore, as shown in FIG. 12, the cylinder 15 of this type is mounted as an actuator 14 connected to the OUT terminal of the Mix slave 13 with a cylinder that returns when the output is turned off, and a sensor 15 ′ that detects the moving body 14a. Is arranged at the intermediate position Y of the return path.

  Then, consider a case where the operation time (t1, t1 ′) from when the moving body 14a starts to move backward until it reaches the intermediate position Y is obtained. In this case, the start time is acquired as a trigger when the OUT terminal is turned OFF. As a trigger for acquiring the stop time, the IN terminal can be turned on (rising) or the IN terminal can be turned off (falling). When the IN terminal is linked to ON, the operation time t1 can be obtained, and when the IN terminal is linked to OFF, the operation time t1 'can be obtained.

  As a function for executing such processing, the former case is based on the flowchart shown in FIG. 6 and can be dealt with by changing the branch determination in step 1 to “whether the corresponding OUT is ON → OFF”. This is an embodiment corresponding to OUT terminal: OFF (falling) → IN terminal ON (rising). Further, the latter case can be dealt with by further changing the branch determination in step 3 to a process of “whether the corresponding IN is ON → OFF”. This is an embodiment corresponding to OUT terminal: OFF (falling) → IN terminal OFF (falling).

  Note that the operation time calculated in the second embodiment and its modification is the upper master unit at various timings such as voluntary or requests from the other party, as shown in the first embodiment. 11 or the PLC unit 10.

  FIG. 13 shows a third embodiment of the present invention. In this embodiment, unlike the above-described embodiments and modifications, the operation time of the device (actuator 14) is obtained based on input signals from two input devices (sensors).

  That is, as in the first embodiment, the actuator 14 is connected to the OUT terminal of the Mix slave 13, and a sensor for monitoring the position of the moving body 14a of the actuator 14 is connected to the IN terminal. However, in the present embodiment, two sensors are prepared as sensors connected to the IN terminal, such as first and second sensors 16a and 16b. The first and second sensors 16a and 16b are arranged in the middle (intermediate position) X and Y of the moving path of the moving body 14a, respectively, and detect that the moving body 14a has passed the intermediate positions X and Y. It is supposed to be. The internal structure of the Mix slave 13 is the same as that shown in FIG.

  According to this system, OUT data is turned ON, and the moving body 14a of the actuator 14 moves forward from the origin position. Then, as shown in FIG. 14, when the moving body 14 a reaches the intermediate position X, the output of the first sensor 16 a is turned ON, and when it passes the intermediate position X, it is turned OFF. This output becomes the input signal of the IN terminal for the first sensor 16a of the Mix slave 13 as it is.

  When the moving body 14a further moves forward, it reaches the intermediate position Y, so that the output of the second sensor 16b is turned ON, and when it passes the intermediate position Y, it is turned OFF. This output becomes the input signal of the IN terminal for the first sensor 16a of the Mix slave 13 as it is.

  In such a case, in order to obtain the operation time required for the moving body 14a to move from the intermediate position X to the intermediate position Y, the outputs of the first and second sensors 16a and 16b, that is, the two corresponding IN terminals The operation time can be obtained by the Mix slave 13 by associating (linking) the signals. Although it is the association of two IN terminals, the acquisition of the start time of the operation time and the acquisition of the stop time are performed using the change of the IN terminal as a trigger, as in the above-described embodiments and modifications thereof. The change can be either OFF → ON (rising) or ON → OFF (falling).

  Therefore, as shown in FIG. 14B, when the rising edge of the output signal (IN terminal) of the first sensor 16a and the rising edge of the output signal (IN terminal) of the second sensor 16b are linked, the time T1 is It becomes operation time. When the rising edge of the output signal (IN terminal) of the first sensor 16a is linked to the falling edge of the output signal (IN terminal) of the second sensor 16b, the time T2 becomes the operation time.

  On the other hand, as shown in FIG. 14 (c), the trigger for acquiring the start time can be the fall of the output signal (IN terminal) of the first sensor 16a. In this case, the time T3 is obtained as the operating time by associating the falling edge of the signal of the first sensor 16a with the rising edge of the output signal (IN terminal) of the second sensor 16b. By associating the trailing edge of the output signal (IN terminal) of the sensor 16b, the time T4 is obtained as the operation time.

  Of course, the operation time when the moving body 14a moves backward can also be obtained. In this case, contrary to the above, the change in the output of the second sensor 16b and the change in the output of the first sensor 16a are linked, the start time is acquired based on the second sensor 16b, and the first sensor The stop time is acquired based on 16a.

  Furthermore, in the above-described example, an example in which the two sensors both detect the intermediate position of the moving path of the moving body (the signal changes from OFF to ON to OFF by passing through) has been described. Of course, the one that detects the position is also good. Furthermore, the monitoring of the two sensors is not limited to monitoring the operation of one device, and may be the monitoring of the operating state of different devices. As an example, a sensor that monitors the operation of two robots may be provided, and a time lag from when one robot starts operation (operation completion) until the other robot starts operation (operation completion) may be obtained. . As described above, the operation time is not limited to the operation time (stop time) of a single device, but is a concept including the operation time of the entire system (device) including a plurality of devices as described above.

  The function of the MPU 13b (processing unit 13b ″) for obtaining the operation time based on the change of the two IN terminals is basically realized by the same processing function as the flowchart shown in FIG. In the flowchart of Fig. 6, Steps 1 and 3 are appropriately changed depending on whether the two IN terminals to be linked acquire each time based on ON or OFF. If the time is acquired based on a change from OFF to ON (rising), the processing in step 1 is changed to “whether the corresponding IN is OFF → ON” and changes from ON to OFF (falling). ), The process of step 1 is changed to “whether the corresponding IN is ON → OFF”. Further, when the acquisition of the stop time is performed based on a change (falling) from ON to OFF, the process of step 3 is changed to “whether the corresponding IN is ON → OFF”.

  In the present embodiment, the slave connecting the first and second sensors 16a and 16b is the Mix slave 13, and the operation control of the actuator 14 is also performed by OUT data (ON / OFF of the OUT terminal) output from the Mix slave 13. Although an example is shown that is executed based on the OFF signal), the control command for the actuator 14 may not be sent from the same slave. In this case, the slave to which the first and second sensors 16a and 16b are connected can be an IN slave instead of the Mix slave, for example. Since other configurations and operational effects are the same as those of the above-described embodiments and modifications thereof, detailed description thereof is omitted.

Further, as shown in FIG. 15, the system configuration in which the first and second sensors 16a and 16b are connected to different IN slaves 21 'and 21 ", respectively, in the calculation of the operation time based on the association between the IN terminals. In this case, as in the second embodiment, the IN value (start time in the example in the figure) acquired by one IN slave 21 'is given to the other IN slave 21''. Then, the operation time is obtained based on the given IN value and the time information (stop time in the example in the figure) acquired on the other IN slave 21 ″ side, and the calculation result is sent to the master unit 11 side.

  Of course, the relationship between the sending-side IN slave and the receiving-side IN slave is arbitrary, and the start time may be sent as shown, or another start time may be obtained from the IN slave that obtained the stop time. It may be sent to the IN slave. Furthermore, as described in the modification of the second embodiment, the obtained time information is sent to various slaves such as the master unit 11 and other slaves to which these two sensors are not connected, The operating time can also be determined there. Since other configurations and operational effects are the same as those of the above-described embodiments and modifications thereof, detailed description thereof is omitted.

  Furthermore, in the case of a node incorporating a function for calculating the operation time of an actual slave or master, there is a demand to be able to cope with any of the above-described patterns. That is, there are four types of patterns for obtaining the operation time from the change of the OUT terminal to the change of the IN terminal, and the operation time from the change of the IN terminal to the change of the IN terminal There are four types of acquisition patterns, and there are a total of eight types of patterns.

  As a function of the MPU 13b (processing unit 13b ″) for dealing with any of the eight types of patterns, for example, it can be dealt with by realizing the flowchart shown in FIG.

  First, as a premise, the association relationship of each terminal is stored as setting data in the external nonvolatile memory 13e. As in the first embodiment, the setting data includes association data as shown in FIG. 17 using the tool device, that is, “node number (MACID) and bit number of slave to which a start trigger is issued” together with an allocation number. “Number and change type (rising / falling) and IN / OUT terminal distinction”, “IN slave node number (MACID) and bit number and change type (rising / falling)” and “ A table in which the “monitoring time unit” is associated is created, and a message (see FIG. 18) including related information in the data part is created for the slave to be stored based on this table, and the tool device or master unit 11 is Via the field network 12 to the corresponding slave Ri can be carried out.

  The monitoring time unit is a unit of time for monitoring the status of other slaves, and the status of the corresponding bit is inquired at the monitoring time interval. Therefore, the monitoring time unit becomes the minimum unit of the operation time measurement function. In addition, although it is the type of the IN / OUT terminal of the start trigger, there is naturally both I / O in the case of a Mix slave.

  Based on this premise, as shown in FIG. 16, first, setting reading is performed (ST10). With this setting, the bit number of the terminal (IN terminal / OUT terminal) to be monitored by itself and the type of change to be triggered for time acquisition are acquired. Next, it is determined whether or not the corresponding OUT / IN terminal has changed (ST11). That is, based on the setting data acquired in step 10, it is determined whether or not the terminal to be monitored that is a trigger for starting time acquisition has risen / falled.

  If there is a change (Yes in the branch determination at step 11), the process proceeds to step 12 to acquire the start time. Next, it is determined whether or not the corresponding IN terminal linked changes (rising / falling is determined by setting data) (ST13). When the rising edge is detected (Yes in step 13), the value of the timer 13f (stop time) is acquired (ST14), the difference from the start time acquired in step 2 is obtained, and the operation time is calculated. The result is stored in the result buffer.

  On the other hand, a setting value that defines the operating time of a normal actuator is stored in advance, and the operating time calculated in step 15 is compared with the setting value to determine whether it is within the range (normal). In addition, the result is stored in the result buffer (ST16).

  Then, if the above-described processing is repeatedly executed sequentially for the set monitoring target and the processing is executed for all the points (Yes in ST17), the obtained operation time and the comparison result are obtained for each monitoring target (actuator 14). Etc.) is stored in the internal volatile memory 13b '(ST18). Since such processing is executed according to the interrupt instruction, if the processing up to step 18 is executed, it waits for the next instruction.

  Note that the operation time calculated in the third embodiment and the modifications thereof is higher at various timings such as voluntary or requests from the other party as shown in the first and second embodiments. The master unit 11 and the PLC unit 10 can be provided.

  As described above in detail, according to each embodiment described above, the time information when the OUT terminal of the slave to which the output device is connected changes, and the slave to which the input device that monitors the output device is connected. Time information when the IN terminal changes is obtained, and the operation time of the output device is obtained from the difference, or from a time interval from when one IN terminal changes to another IN terminal, The operation time of the device (system) can be obtained. Moreover, since the calculation processing and the like are performed on a node side such as a slave or a master connected to the network, the operation time of the output device can be accurately measured without being affected by the cyclic time on the PLC side.

  In each of the above-described embodiments, an operation time that is a measured value of a physical quantity related to a control device (input device and / or output device) is obtained by a slave, and compared with a reference value. The comparison result and / or the operation time are output to the field network 12 and given to a predetermined device (node) connected to the field network 12. In the present invention, the present invention is not limited to this. For example, the operation time obtained at a predetermined timing may be output without comparing with a reference value, and the determination may be performed by the PLC unit 10 or the like. The transmission destination is not limited to the master unit or the slave, but may be a configurator or a monitor as well as a PLC and other controllers.

  Furthermore, the information to be notified may be transmitted as unique information (non-control information) of the control device in addition to the determination result and / or the operation time. That is, for example, when the operation time is longer than the reference value, if it is set to approach the replacement time, unique information indicating the ID of the device (device name, manufacturer name, format, serial number) ) And the like together, the user can know in advance information about the failed device. Therefore, when going to the site, it is possible to carry a replacement part for the device or a device to be replaced, and to perform maintenance quickly. Then, each slave can be dealt with by storing in advance the unique information about the control device connected to itself, and reading and transmitting it as necessary.

  In addition, the physical quantity relating to the measurement target control device or the slave itself in the present invention is not limited to the operation time described above, and there are various other things such as the power supply voltage supplied to the slave.

  FIG. 19 is a system configuration diagram showing the overall configuration of the fourth embodiment. This embodiment is a network system in which one master unit 30 and a plurality of slaves 33 distributed at a plurality of locations are connected via a field network 32. Devices (input / output devices 34) such as input devices and output devices are connected to the slave 33, and I / O data of the input / output devices 34 is transmitted to and received from the master unit 30. This is the same in each of the above-described embodiments and modifications thereof.

  Although not shown, a PLC unit is connected to the master unit 30 in the same manner as in each of the above-described embodiments to constitute a PLC. Further, the PLC unit and the master unit 30 are not necessarily connected directly to form the PLC, and the master unit 30 may be independent from the PLC. In this case, I / O data is exchanged via the field network 32 or another network.

  A network power supply device 35 is installed near the master unit 30. The network power supply 35 is connected to the field network 32, and a power supply voltage is supplied to the master unit 30 and the slave 33 via the field network 32. Further, power is also supplied to the input / output device 34 via the slave 33. Furthermore, a network configurator 36 is connected to the field network 32, and power is also supplied to the network configurator from the network power supply device 35.

  The network configurator 36 monitors the status of network units such as the master unit 30 and the slave 33, and reads and writes parameters.

  The slave 33 is composed of a remote I / O terminal, environment resistant terminal, remote adapter, I / O link unit, sensor terminal, analog input terminal, analog output terminal, temperature input terminal, RS232C unit, etc. that constitute this system. It is what is done.

  In the above configuration, each of the plurality of slaves 33 performs an operation such as communication using a network power supply supplied from the network power supply device 35 through the field network 32. The network power supply is at a distance from the network power supply device 35. Each receives a different voltage drop. In this embodiment, since the network power supply is also supplied to the input / output device 34, when the input / output device 34 consumes power, the voltage drop increases accordingly.

  The operation guarantee voltage of the plurality of slaves 33 is determined to be, for example, 24V to 11V, so that the power supply voltage at the position supplied to the slave of the network power supply is, for example, 11V or less. It becomes impossible to communicate.

  Therefore, in the system according to this embodiment, power supply monitoring means for monitoring the state of the network power supply applied to each slave 33 is provided. Then, the power supply state information indicating the state of the network power supply of each slave 33 monitored by the power supply monitoring unit is collected by the network configurator 36 via the field network 32 by communication with the network configurator 36, and the network of each slave 33 is collected. The power supply state is configured to be centrally managed by the network configurator 36.

  FIG. 20 is a block diagram showing a main configuration of each slave 33 in the PLC system shown in FIG. 20, the slave 33 includes a voltage monitoring unit 33a, a maximum / minimum value holding unit 33b, a current value storage unit 33c, a monitoring voltage storage unit 33d, a comparison unit 33e, an alarm status storage unit 33f, and a communication control unit 33g. Configured.

  Here, the voltage monitoring unit 33a monitors the network power supplied from the field network 32 and detects the current value, the maximum value, and the minimum value. The maximum value and the minimum value of the network power supply voltage detected by the voltage monitoring unit 33a are held in the maximum / minimum value holding unit 33b. The current value of the network power supply voltage detected by the voltage monitoring unit 33a is stored in the current value storage unit 33c.

  The slave 33 communicates voltage information, which is one of non-control system information that is not I / O data stored in the maximum value / minimum value holding unit 33b and the current value storage unit 33c, to the network configurator 36, and The contents can be confirmed by the configurator 36. Further, it has a function of determining whether or not the current supply voltage is normal and storing the determination result. In the case of a completely abnormal state where the supply voltage becomes inoperable, it is impossible to determine whether the device is normal because the device itself does not operate. Therefore, in the present embodiment, a state close to a voltage at which the supply voltage decreases and the supply voltage becomes inoperable is abnormal, i.e., a state in which some kind of alarm is required, and the state in which such a state is reached is recorded. ing.

  In the present embodiment, a monitoring voltage that is used as a criterion for determining whether or not the alarm is necessary, that is, a state where the alarm is in operation but is likely to become inoperable, 33d. In this embodiment, the monitoring voltage is set by a dip switch (not shown) of the slave 33.

  For example, when the operation guarantee voltage of the slave 33 is 24V to 11V, the monitoring voltage stored in the monitoring voltage storage unit 33d is set to a value slightly higher than 11V that is the lower limit voltage. As an example, it is set to 12V. With this setting, it becomes possible to communicate the state of the network power supply supplied to the slave 33 to the network configurator 36 before communication becomes impossible due to a decrease in supply voltage due to a voltage drop.

  The comparison unit 33e compares the current value of the network power supply voltage stored in the current value storage unit 33c with the monitoring voltage stored in the monitoring voltage storage unit 33d, and the current value of the network power supply voltage is the comparison reference value. When the voltage falls below the monitoring voltage, an alarm status is output.

  The alarm status output from the comparison unit 33e is stored in the alarm status storage unit 33f. Here, the storage of the alarm status in the alarm status storage unit 33f can be stored as an error flag.

  The slave 33 holds information relating to the supply voltage, including the alarm status (error flag) that is the determination result based on the monitoring voltage. In this embodiment, the information held by the slave is passed to the network configurator 36 as a response transmitted in response to a request from the network configurator 36. That is, the maximum and minimum values of the network power supply voltage supplied to the slave 33 held in the maximum / minimum value holding unit 33b and the network power supply supplied to the slave 33 stored in the current value storage unit 33c. The current value of the current voltage and the alarm status stored in the alarm status storage unit 33f are obtained by a read command from the network configurator 36 shown in FIG. 19, and the maximum value / minimum value holding unit 33b, current value storage unit 33c, alarm status The data is read from the storage unit 33f to the communication control unit 33g, and transmitted as a response from the communication control unit 33g to the network configurator 36 via the field network 32.

Further, the timing of communication of information related to the voltage is not limited to an external trigger as in the case of a response transmitted in response to reception of a command issued from the network configurator 36 as described above. The slave 33 may be configured to voluntarily transmit on the condition that there has been a change in. That is, the supply voltage to the slave 33 is monitored, and when the voltage falls below a certain threshold value (monitoring voltage), an alarm status (error flag) and other voltage information are transmitted to the network configurator 36. Also good.

  Note that the voltage monitoring configuration shown in FIG. 20 can also be provided in the master unit 30. With this configuration, similarly to the slave 33 described above, the voltage supplied from the network power supply device 35 to the master unit 30 can be monitored.

  FIG. 21 is a block diagram showing a main configuration of the network configurator 36 in the present embodiment. As shown in FIG. 21, the network configurator 36 includes an input unit 36a, a communication control unit 36b connected to the field network 32, and a display unit 36c. Specific functions of each part are as follows.

  The input unit 36a is a man-machine interface such as a keyboard, a pointing device, and an operation panel, and has a function of passing a voltage display instruction of this system received in response to a user operation to the communication control unit 36b.

  In accordance with the voltage display instruction given from the input unit 36a, the communication control unit 36b sequentially issues a current value read command, a maximum value read command, a minimum value read command, and an alarm status read command to each slave 33. The current value, maximum value, minimum value, and alarm status of the network power supply voltage in each slave 33 are collected by receiving a response from the slave 33. Then, the collected information is transferred to the display unit 36c.

  The display unit 36c is a display device such as a display, and outputs and displays the network power state of each slave 33 received from the communication control unit 36b. Thereby, the current voltage state can be notified to the user. In this way, the status of each slave 33 can be collected by the network configurator 36 regardless of the normal transmission / reception of I / O data by communication of a system different from the cyclic processing of the PLC unit. Centralized management.

  Next, a specific processing procedure for realizing the above-described processing, that is, the function for the network configurator 36 to collect information on the voltage of the power supply held by each slave 33 will be described.

  FIG. 24 is a flowchart showing the processing of the network configurator 36. First, it is determined whether or not a voltage display instruction for each slave 33 is input from the input unit 36a (ST21). When the voltage display instruction is not input (NO in step 21), it waits for the voltage display instruction to be input again, but it is determined that the voltage display instruction is input (step 21 branch). If the determination is YES), the unit number n of the slave 33 is set to "1" (ST22). Next, it is determined whether the unit number n is the last number (ST23). When executed after step 22, since n = 1, it is not the last number, so the branch determination is NO.

  If the unit number n is not the last (NO in step 43), a current value read command for instructing reading of the current value of the network power supply voltage supplied to the slave 33 is sent to the slave of unit number n. (ST24).

  Then, it is determined whether a response to the current value read command from the slave 33 of unit number n has been received (ST25). If no response has been received (NO in step 25), this response is awaited. When the response is received (YES in step 25), a maximum value read command for instructing reading of the maximum value of the network power supply voltage of slave 33 is issued to slave 33 of unit number n (ST26).

  Then, it is determined whether a response to this maximum value read command has been received from the slave 33 of unit number n (ST27). If no response has been received (NO in step 27), this response is awaited. When the response is received (YES in step 27), a minimum value read command for instructing reading of the minimum value of the network power supply voltage supplied to the slave 33 is issued to the slave 33 of unit number n (ST28).

  Then, it is determined whether a response to this minimum value read command has been received from the slave 33 of unit number n (ST29). If no response has been received (NO in step 29), this response is awaited. When the response is received (YES in step 29), an alarm status read command for instructing reading of the alarm status of the network power supply supplied to the slave 33 is issued to the slave of unit number n (ST30).

  Then, it is determined whether a response to the alarm status read command is received from the slave 33 of unit number n (ST31). If no response is received (NO in step 31), this response is awaited. When a response is received (YES in step 31), the unit number n is incremented to n + 1 (ST32), and then the process returns to step 23. If a response is received at each processing step described above, the content sent as the response is extracted and stored.

  The above processing is repeated until it is determined in step 23 that the unit number n is the last. Note that the last value of the unit number n is stored and held in advance. Strictly speaking, the determination of “is it the last?” In step 23 is “has the last number been exceeded” or “has it been processed to the end?”. If the processing has been executed up to the last number (YES in step 23), the status of the network power supply of each slave 33 based on the current value, maximum value, minimum value, and alarm status obtained by executing each processing described above. Is displayed (ST33). As a result, a series of processes such as command issuance, response reception, and display of information acquired by the response accompanying the input of the current voltage display instruction are completed. In the above description, the command is issued to the slave. However, by adding the number assigned to the master unit to the unit number, information on the network voltage supplied to the master unit is acquired. be able to.

  As a specific example of the display of the power state on the display unit 36c obtained as a result of executing the process of step 33, for example, there is the one shown in FIG. Here, it is assumed that information regarding the network voltage supplied to the master unit 30 is also acquired. The upper part of the display screen 37 shown in FIG. 23 shows the connection configuration of this FA system comprising the master unit 30 (M) and each slave 33 (S1 to S6), and the lower part is supplied to each unit. The maximum value L1, the current value L2, and the minimum value L3 of the network power supply are displayed in a line graph.

  L4 is a monitoring voltage stored in the monitoring voltage storage unit 33d. If there is a unit whose minimum value L3 or current value L2 is lower than the monitoring voltage L4, it is abnormal. An alarm screen is displayed.

  Whether to issue an alarm by comparing the monitoring voltage L4 and the minimum value L3 or by comparing the current value L2 depends on the configuration of the FA system, the electrical characteristics of the external device connected to the slave 33, and the like. It is good to choose. Also, an alarm to that effect may be issued when any of the comparison values of the minimum value L3 and the current value L2 falls below.

  According to such a configuration, the state of the network power supply of each slave 33 can be visually shown to the user in relation to the maximum value L1, the minimum value L3, the current value L2, and the monitoring voltage L4.

  In addition, the display example of the power supply state is not limited to the above, and another example can be shown in FIG. That is, the upper part of the display screen 37 shown in FIG. 24 shows the connection configuration of the FA system including the master unit 30 (M) and the slaves 33 (S1 to S6). This is the same as described above. In the lower part, the maximum value L1 ′, the current value L2 ′, and the minimum value L3 ′ of the network power supply supplied to each unit are displayed in a bar graph.

  L4 is a monitoring voltage stored in the monitoring voltage storage unit 33d. If there is a unit whose minimum value L3 or current value L2 is lower than the monitoring voltage L4, it is abnormal. An alarm screen is displayed.

  Whether to issue an alarm by comparing the monitoring voltage L4 and the minimum value L3 or by comparing the current value L2 depends on the configuration of the FA system, the electrical characteristics of the external device connected to the slave 33, and the like. It is good to choose. Also, an alarm to that effect may be issued when any of the comparison values of the minimum value L3 and the current value L2 falls below.

  23 and 24, there is no alarm status display, but this alarm status can be configured to be displayed corresponding to the connection configuration of the FA system shown in each figure. You may comprise so that it may display on a display screen different from this display screen.

  By the way, the current value of the network power supply voltage indicates the operating state of an external device such as a motor connected to the slave 33 and the load of other slaves connected in the middle of the network power cable from the network power supply device 35 to the slave 33. It varies constantly depending on the situation. Therefore, when the voltage drop for a very short time does not cause the slave 33 to stop functioning or deteriorate in performance, the voltage detection means (voltage monitoring unit) detects only the voltage that lasts for a predetermined time or more as abnormal. Is preferred.

  The maximum and minimum values of the network power supply voltage are effective for grasping the range of voltage fluctuation, and the current value is effective for grasping the current state. If an alarm is issued when the current value of the network power supply voltage falls below the monitoring voltage, it can be managed more safely.

  On the other hand, the processing in each slave 33 is as shown in the flowchart of FIG. That is, first, it is determined whether a command has been received from the network configurator 36 (ST51). If no command is received from the network configurator 36 (NO in step 51), the process returns to step 51 again. That is, command reception is awaited by the processing of step 51.

  If it is determined in step 51 that a command is received from the network configurator 36 (YES in step 51), it is then determined whether the received command is a current value read command (ST52). If the received command is a current value read command (YES in step 52), the current value of the network power supply of the slave stored in the current value storage unit 33c is read and the current value is read from the communication control unit. A response to the command received by 33g is returned to the network configurator 36 (ST53). Thereby, the process associated with the current command reception is terminated.

  If the received command is not a current value read command (NO in step 52), the process jumps to step 54 to determine whether the received command is a maximum value read command (ST54). If the received command is a maximum value read command (YES in step 54), the network power supply is supplied with the maximum value of the network power supplied to the slave 33 stored in the maximum value / minimum value holding unit 33b as a response. It returns to the configurator 36 (ST55). Thereby, the process associated with the current command reception is terminated.

  If it is determined in step 54 that the received command is not the maximum value read command, the process jumps to step 56 to determine whether the received command is the minimum value read command (ST56). If the received command is a minimum value read command (YES in step 56), the network is sent with the minimum value of the network power supplied to the slave 33 stored in the maximum value / minimum value holding unit 33b as a response. It returns to the configurator 36 (ST57). Thereby, the process associated with the current command reception is terminated.

  If it is determined in step 56 that the received command is not the minimum value read command, the process jumps to step 58 to determine whether the received command is an alarm status read command (ST58). If the received command is an alarm status read command (YES in step 58), the slave network power supply alarm status stored in the alarm status storage unit 33f is returned as a response to the network configurator 36 (ST59). Thereby, the process associated with the current command reception is terminated.

  Furthermore, if the branch determination in step 58 is NO, that is, if the received command is not an alarm status read command, the command received this time is not a command for reading information on the network voltage, and therefore corresponds to the received command. The other processing is executed (ST60). Thereafter, the process returns to step 51 to wait for reception of the next command.

  In the above-described embodiment, the monitoring voltage is manually set for each slave by an operation switch (such as a dip switch or a rotary switch) on the slave. However, the monitoring voltage may be set by an operation from the network configurator 36 via the field network 32. When the monitoring voltage is set by the operation from the network configurator 36, it is set for each slave connected to the network, or when the operating voltage of each slave is the same, it is set all at once. You can also.

  Further, only a slave disposed far from the network power supply device 35 or a slave having a large load current of the connected external device has a network power supply monitoring function, and the network power supply monitoring information of the slave is sent to the network configurator 36. May be displayed.

  In addition, when all the slaves 33 are provided with a network power supply monitoring function, the network configurator 36 selectively sends a network power supply monitoring information collection command to specific slaves, and the network power supply of these specific slaves. The monitoring information may be displayed.

  In the above-described embodiment, all the slaves 33 have been described as having power supply monitoring means. By the way, as a configuration of the network system, there are cases where a slave having a power supply monitoring unit and a conventional slave having no power supply monitoring unit coexist. In this case, since the conventional slave responds to an error response to the current value read command from the network configurator 36, the network configurator 36 indicates that the slave is a conventional slave having no power source monitoring means. Judgment can be made. Further, since the network configurator 36 can determine the model of the slave connected via the field network, it is possible to issue a current value read command or the like only to the slave having the power supply monitoring means. Therefore, the present invention can also be applied to a network system in which a slave having power supply monitoring means and a conventional slave having no power supply monitoring means coexist.

  Furthermore, the master unit in the present invention is not limited to one, and can be applied to a PLC system in which a plurality of master units are connected.

  As described above, according to the embodiment described above, the network power supply state can be centrally monitored at one place during system construction, so that the system construction time can be shortened. In addition, since the network power supply state during system operation can be checked at any time, the system can be easily maintained and maintained.

  In the above-described embodiment, the collecting device is described as a network configurator. However, information stored in each slave may be sent to a monitor connected to the field network and displayed on the monitor. Of course, the non-I / O data may be exchanged with the master unit.

  Also in the present embodiment, information relating to the voltage supplied to the slave or the like is detected and stored on the slave side, and collection and display of the information is performed based on a request from the configurator. Does not affect the cyclic processing.

  FIG. 26 and subsequent figures show a fifth embodiment of the present invention. In the present embodiment, an I / O power source supplied to an input / output device connected to the slave is used as a physical quantity related to the measurement target control device or the slave itself.

  As shown in FIG. 26, this FA system is configured by connecting one master unit 40, which is an upper station, and a plurality of slaves 43 distributed in a plurality of places to a field network 42. As in the above-described embodiments, a field bus (for example, DeviceNet (registered trademark)) is used as the field network 42 that is a network between the master unit 40 and the plurality of slaves 43. It is done.

  Here, the master unit 40 constitutes a PLC master in the FA system. Further, as in FIG. 3 and the like, the PLC unit is linked.

  The slave 43 inputs a signal from a detector such as a sensor and outputs a signal to a controller such as a valve. That is, a predetermined input / output device 44 is connected to perform control by the FA system. The input / output device 44 includes an input device 44a such as a sensor and an output device 44b such as a valve / motor. The output of the input / output device power supply device 45 is connected to each slave 43 so that the input / output device power supply 45 receives power supply to each input / output device 44.

  Furthermore, as shown in FIG. 27, the input / output device power supply device 45 includes an input power supply unit 45a that supplies power to an input device 44a such as a sensor and an output power supply unit 45b that supplies power to an output device 44b such as a valve. Yes. The supply voltages from the input power supply unit 45a and the output power supply unit 45b are also supplied to the input / output device power supply monitoring unit 43a. Thereby, the input / output power supply monitoring unit 43a can determine ON / OFF by monitoring the voltage value and comparing it with a threshold value.

  Although power supply to the slave 43 itself is not shown, it can be supplied from the network power supply device 35 connected to the field network 32 as in the fourth embodiment. Of course, it is also possible to receive power separately from the power supply terminal of the slave without going through the network. The slave in this case is provided with an input / output device power supply terminal and a slave power supply terminal separately and independently. Also in this case, since a slave power supply prepared separately is input to the slave via the power supply terminal, the terminal voltage of the slave power supply is measured, compared with a reference value, and the comparison judgment result is transmitted to the network. It may be notified to the master unit, the monitor, the configurator, or the like.

  In the above-described configuration, the plurality of slaves 43 have input / output devices that monitor whether the input power supplied from the input power supply unit 45a and the output power supplied from the output power supply unit 45b are ON or OFF, respectively. A power supply monitoring unit 43a is provided (see FIG. 27).

  Each slave 43 holds input / output device power status information indicating ON / OFF states of the input power and output power monitored by the input / output device power monitoring unit 43a. The input / output device power status information (I / O power information) is transmitted to the master unit 40 via the field network 42 in response to a request from the master unit 40. Thereby, in the master unit 40, the state of the input / output device power supply (I / O power supply) of the plurality of slaves 43 can be monitored.

  With the above configuration, in the master unit 40, when no signal is received from the input device 44a such as a sensor, the cause is that the input power source of the slave 43 is OFF, or the input device 44a such as the sensor is actually faulty. It is possible to quickly determine whether a signal is not input, thereby improving the reliability of the system.

  Similarly, the master unit 40 outputs a signal for driving a controller such as a valve (output device 44b) to the slave 43, but the operation of the output device 44b such as the valve cannot be confirmed. Therefore, it can be determined whether the output power of the slave 43 is OFF or because no signal is actually output to the slave 43. This also improves the reliability of the system.

  In a PLC unit (not shown) connected to the master unit 40 (captures information from an input device, executes a control program, and outputs an execution result to an output device), the power supply state of the device connected to the slave 43 is determined. It becomes possible to know via the master unit 40. Therefore, it is possible to cope with a device connected to the slave when the power is turned off by a control program (programmed by a ladder language or the like) of the PLC unit (CPU unit), so that the reliability of the system can be improved.

  FIG. 28 is a block diagram illustrating a specific configuration example of the slave 43 illustrated in FIG. FIG. 28 shows a case where a sensor 44a as a detector is connected to the slave 43, but a case where a valve or the like as a controller is connected and a sensor or the like as a detector and a controller. The same configuration can be made when both of the valves and the like are connected. However, when a valve or the like is connected, not the input power supply but the output power supply is monitored.

  First, the detection signal of the sensor 44a is given to the input unit 43b. A detection signal from the sensor 44a acquired by the input unit 43b, that is, ON / OFF information is given to the master unit 40 via the field network 42 via the communication control unit 43c. In this way, the I / O data is transmitted, but the processing function is the same as the conventional one. The input power supply is given to the sensor 44a via the slave 43, but is given to the input power supply monitoring unit 43a '. The input power supply monitoring unit 43a ′ constantly monitors ON / OFF of the input power supply input from the outside based on the applied input power supply voltage.

  When the communication control unit 43c receives a request sent from the master unit 40 via the field network 42, it indicates ON / OFF of the input power source monitored by the input power source monitoring unit 43a 'based on this request. The information is acquired by the communication control unit 43 c and this information is transmitted to the master unit 40 via the field network 42.

  Of course, in FIG. 28, the monitoring function for the input power supply is illustrated and described. However, in the case of the slave to which the output device is connected as described above, an output power supply monitoring unit is provided to turn on the output power supply. , OFF information is monitored, and the ON / OFF information is returned as a response in response to a request from the master unit 40. The input / output device power supply monitoring unit 43a shown in FIG. 27 collectively describes the monitoring of the input power supply and the output power supply. That is, FIG. 27 shows an example in which only the input / output device power supply monitoring unit 43a is provided in the slave 43, but actually, as in FIG. 28, the communication control unit and the I / O of the input / output device are shown. An input unit and an output unit for managing data are provided. An example of the processing algorithm of the master unit 40 and the slave 43 for managing / transmitting / receiving the ON / OFF information of the input / output power supply is as shown in the flowcharts of FIGS.

  FIG. 29 is a flowchart for explaining the operation of the slave 43. As shown in FIG. 29, first, the input / output device power supply monitoring unit 43a determines whether the input power supply and the output power supply are ON (ST61). In this determination, a threshold value close to 0V may be set, and if it is more than that, it may be determined to be ON, or an input power source and an output power source are applied to the base voltage of the transistor as will be described later. In this configuration, various methods such as determining that the power is turned on when the transistor is turned on can be employed. In any case, it is compared with some judgment reference value, and when the judgment reference value becomes abnormal, it is judged that the voltage is ON.

  If the input power source or output power source is ON (YES in step 61), the corresponding input power source and output power source error flags are set to OFF (ST62). If the input power source and output power source are OFF (NO in step 61), the error flag corresponding to the input power source and output power source turned OFF is set to ON (ST63).

  Next, it is determined whether there is a request for input / output device power status information from the master unit 40 via the feed network 42 (ST64). If there is no request for input / output device power status information (NO in step 64), the process returns to step 61 and proceeds to the next process.

  On the other hand, if a request for input / output device power status information is received (YES in step 64), the error flag is transmitted as input / output device power status information via the feed network 42 as a response to the master unit 40, and thereafter Then, the process returns to step 61 and proceeds to the next process.

  FIG. 30 is a flowchart for explaining the operation of the master unit 40. First, it is determined whether there is an input / output device power supply check instruction (ST71). This instruction may be a request from the PLC unit side, for example. It is also possible to determine that there is an instruction to check the input / output device power supply by providing an operation button for checking the input / output device power supply to the master unit 40 and pressing the operation button.

  If there is no input / output device power supply check instruction (NO in step 71), the flow returns to step 71 to wait for an input / output device power supply check instruction. If it is determined that there is an input / output device power supply check instruction (YES in step 71), then the unit number n of the slave 43 is set to "1" (ST72). Next, it is determined whether or not the unit number n is the last number (ST73). When executed after step 72, since n = 1, it is not the last number, so the branch determination is NO.

  If the unit number n is not the last (NO in step 73), a request for reading the error flag of the input / output device power supply to the slave of unit number n is issued (ST74), and the input / output device from the slave of unit number n is issued. The power error flag is read (step 75).

  Then, processing corresponding to the read error flag of the input / output device power supply is performed (ST76), then the unit number n is incremented to n + 1 (ST77), and the process returns to step 73.

  The above process is repeated until it is determined in step 73 that the unit number n is the last. Note that the last value of the unit number n is stored and held in advance. Strictly speaking, the determination of “is it the last?” In step 73 is “has the last number been exceeded?” Or “has the process been completed?”. If processing has been executed up to the last number (YES in step 73), a series of processing accompanying the current input / output device power supply check instruction is terminated.

  The processing according to the error flag in step 76 is performed based on, for example, a ladder program installed in the master unit 40, and “input / output device power supply normal”, “No. 3- Notification of “slave input power supply OFF” or the like is performed, and if it is inappropriate to continue the operation, processing such as stopping the operation is performed.

  In the flowchart shown in FIG. 30, the configuration is such that the slave input / output device power supply is checked sequentially for all slaves in this system. However, the configuration may be such that it is performed only for the above.

  In the fifth embodiment described above, a system of a type in which power supply to the input / output device is supplied from the input / output device power supply device 45 is premised. However, as described in the fourth embodiment, from the network power supply device. Even in a system that supplies power to an input / output device via a slave, the slave side monitors the ON / OFF state of power supply to the input / output device, and notifies the result to the master unit 40 or the like via the feed network 42. It can also be done. As an example, the internal configuration of the slave 43 can be realized as shown in FIG.

  FIG. 31 shows a case where a sensor 44a as a detector is connected to the slave 43, but a case where a valve or the like as a controller is connected and a sensor or the like as a detector and a controller. The same configuration can be made when both the valves and the like are connected. However, when a valve or the like is connected, not the input power supply but the output power supply is monitored.

  First, the detection signal of the sensor 44a is given to the input unit 43b. A detection signal from the sensor 44a acquired by the input unit 43b, that is, ON / OFF information is given to the master unit 40 via the field network 42 via the communication control unit 43c. In this way, the I / O data is transmitted, but the processing function is the same as the conventional one. The input power is supplied from the network power supply 47 connected to the feed network 42 to the slave 43 via the field network 42. And it is given to the sensor 44a via the slave 43 further. A short circuit protection circuit 43d is provided in the middle of the power supply line to the sensor 44a in the slave. For example, when the short circuit protection circuit 43d detects that a short circuit has occurred on the sensor 44a side, the short circuit protection circuit 43d performs control to shut off the circuit (open the switch). That is, the network power is supplied to not only the sensor 44a and the slave 43 to which the sensor 44a is connected, but also other slaves connected to the field network 42 and the like. Therefore, if a short circuit occurs in the sensor 44a, the power supply system of the entire network is affected in that state. Therefore, the short circuit protection circuit 43d is provided so that the sensor 44a that has caused the short circuit is disconnected from the power supply system. Yes. Since the configuration of the short circuit protection circuit 43d itself is conventionally known, a detailed description of its internal configuration is omitted.

  A supply line from the short-circuit protection circuit 43d to the sensor 44a is branched and supplied to the input power supply monitoring unit 43a '. The input power supply monitoring unit 43a 'constantly monitors the ON / OFF of the input power supply input from the outside based on the applied input power supply voltage.

  According to such a configuration, it is possible to monitor the ON / OFF state of the input power supply including the operation state of the short-circuit protection circuit 43d. That is, the input power supply monitoring unit 43a ′ monitors the ON / OFF of the input power supply, and returns information on the voltage state as a monitoring result to the master unit 40 or the like in response to a request from the master unit 40 or the like. Therefore, the master unit 40 that has received the information indicating that the power supply from the slave 43 to the sensor 44a is OFF via the field network 42 determines that the short-circuit protection circuit 43d of the slave 43 has been activated and has been cut off. be able to. That is, in this embodiment, the slave 43 is also operated by the network power supply. Therefore, when there is a response (information notification) from the slave, it can be said that at least the slave 43 is supplied with the network power, and in this state, the fact that the power supply to the sensor 44a is OFF is a short circuit. It can be determined that the protection circuit 43d is operating.

  Note that the transmission process of information from the slave 43 in response to a request from the master unit 40 is performed via the communication control unit 43c, similarly to the slave in FIG. That is, when the communication control unit 43 c receives a request from the master unit 40, the monitoring result of the input power supply monitoring unit 43 a ′ is acquired and sent to the master unit 40 via the field network 42.

  In addition, instead of simply determining ON / OFF, whether or not the voltage value of the input / output power supply is equal to or higher than a predetermined threshold, as in the monitoring of the network power supply of each slave in the fourth embodiment. It may be determined that the input / output device is operable but is in a state close to the lower limit and the determination result is notified.

  By the way, as a specific circuit configuration for realizing the above-described input power supply monitoring unit 43a ′, it can be configured as shown in FIG. 32, for example. This circuit can be applied to any of the input power supply monitoring units 43a 'shown in FIGS. Further, FIG. 32 shows a monitoring circuit for the input power supply, but a monitoring circuit for the output power supply can be similarly configured.

  As shown in FIG. 32, this input power supply monitoring circuit connects a resistor 51 and a light emitting diode 52a constituting a photocoupler 52 in series to a path branched from a power supply line to an input device 44a. It has been dropped. Further, a pull-up resistor 53 is connected in series between the light receiving transistor 52b constituting the photocoupler 52 and the power supply voltage Vcc. The connection point between the pull-up resistor 53 and the light receiving transistor 52 b is connected to the input terminal of the CPU 54 of the slave 43.

  With this configuration, when the input power supply is ON, a current flows from the input power supply to the ground via the resistor 51 → the light emitting diode 52a of the photocoupler 52, and the light emitting diode 52a is lit. As a result, the light receiving transistor 52b of the photocoupler 52 is turned on, and the input terminal of the CPU 54 is grounded, so that a low level signal is input.

  Further, when the input power supply is OFF, there is no current flowing from the input power supply to the ground via the light emitting diode 52a of the resistor 51 → the photocoupler 52, and the light emitting diode 52a is turned off. As a result, the light receiving transistor 52b is turned off and the input terminal of the CPU 54 is opened, so that a high level signal is input to the input terminal of the CPU 54 by the action of the pull-up resistor 53.

  Therefore, the CPU 54 monitors the level of the signal input to the input terminal, and can detect that the input power source is ON when it is at a low level and that the input power source is OFF when it is at a high level. Then, the operating voltage of the light receiving transistor 52b (the voltage at which the light receiving transistor 52b is turned ON) becomes the reference value for the ON / OFF of the input voltage.

  When there are a plurality of input devices connected to the slave, monitoring of the power supply from the slave may be performed individually for each input device, or all the input devices may be performed collectively. Similarly, when there are a plurality of output devices connected to the slave, monitoring of the power supply from the slave may be performed individually for each output device, or all the output devices may be performed collectively.

  Furthermore, as in the modification of the fifth embodiment, when information on the presence / absence of a short circuit is sent, information on input / output devices may be sent together. That is, when a short circuit occurs, maintenance such as repair / replacement of the shorted input / output device often occurs. Therefore, information about input / output devices connected to the slave in advance, that is, information (device name, manufacturer name, type, serial number) indicating the device ID is stored in advance in each slave, When the information indicating the ID of the shorted device is output together, the user can know in advance information about the failed device. Therefore, when going to the site, it is possible to carry a replacement part for the device or a device to be replaced, and to perform maintenance quickly.

  As described above, according to the fifth embodiment and its modification, the upper station can acquire the state of the power supply (I / O power supply) for input / output devices connected to each slave. It is possible to quickly determine in the upper station whether the cause when the signal is not received is because the power is not supplied to the input device or because the signal is not actually input or output. Therefore, there is an effect that the reliability of the system can be improved.

  In the fifth embodiment, an example of a master unit is shown as an upper station that receives notification of information such as ON / OFF of an I / O power supply and a voltage value. However, the present invention is not limited to this. Other controllers may be used. Furthermore, regardless of the concept of the upper station, a configurator as in the fourth embodiment or the monitor 46 may be used. Furthermore, various nodes connected to the network such as other slaves can be the transmission destination.

  This can be said also in the first to fourth embodiments. That is, the transmission destination of information acquired by each slave can be sent to various nodes connected to the network.

Furthermore, the slave described in each of the above embodiments transmits / receives I / O information to / from the master unit, and transmits / receives I / O information to / from the controller (PLC) via the master unit. In this example, the master-slave method is described in which the desired slave returns a response to the request from the master between the master unit and the slave. However, the present invention is not limited to communication between master and slave. That is, although the slave is called, any communication method can be used. In that respect, strictly speaking, it can be said to include a different concept from a generally defined slave. In other words, the slave according to the present invention has an arbitrary communication protocol for actually transmitting and receiving as long as it has a function of transmitting and receiving I / O information necessary for control with the controller. In particular, the transmission destination of the non-I / O information to be transmitted in the present invention is not limited to the master unit or the controller, and can be various nodes such as a configurator, a monitor, and other slaves connected to the network. Therefore, the communication method can be appropriately selected according to the transmission partner. Of course, the trigger for transmission is not limited to the one triggered by an external request, it can be transmitted based on an internal trigger (internal timer, event that occurs when a certain condition is met, etc.) Also good.
The data can be output to a line (network) and notified to a predetermined transmission destination.

It is a figure which shows a prior art example. It is a figure which shows a prior art example. It is a figure which shows the structure of the network system to which the 1st Embodiment of this invention is applied. It is a figure which shows an example of the internal structure of the slave which concerns on this invention. It is a timing chart which shows the operation state of OUT terminal and IN terminal. It is a flowchart explaining the function of MPU. It is a figure which shows an example of the transmission frame for transmitting a calculation result. It is a figure which shows the structure of the network system to which the 2nd Embodiment of this invention is applied. It is a figure which shows an example of the data structure of the table which correlates OUT slave and IN slave. It is a figure which shows an example of the message for setting the association data of OUT slave and IN slave with respect to a predetermined slave. It is a figure explaining the modification of 1st Embodiment. It is a figure explaining the other modification of 1st Embodiment. It is a figure which shows the structure of the network system with which the 3rd Embodiment of this invention is applied. It is a figure explaining the effect | action in the 3rd Embodiment of this invention. It is a figure which shows the structure of the network system with which the modification of the 3rd Embodiment of this invention is applied. It is a flowchart explaining the function of the composite type apparatus which mounted each embodiment of this invention. It is a figure which shows an example of the data structure of the table which links | relates two slaves. It is a figure which shows an example of the message for setting the association data of two slaves with respect to a predetermined slave. It is a figure which shows the structure of the network system with which the 4th Embodiment of this invention is applied. It is the block diagram which showed the principal part structure of each slave in 4th Embodiment. It is the block diagram which showed the principal part structure of the network configurator in 4th Embodiment. It is a flowchart which shows the process of the network configurator in 4th Embodiment. It is a figure which shows the specific example of the power supply state display process of the network configurator in 4th Embodiment. It is a figure which shows the specific example of the power supply state display process of the network configurator in 4th Embodiment. It is a flowchart which shows the process of each slave in 4th Embodiment. It is a figure which shows the structure of the network system with which the 5th Embodiment of this invention is applied. It is a block diagram for demonstrating the function of 5th Embodiment. It is a block diagram which shows the specific structural example of the slave in 5th Embodiment. It is a flowchart for demonstrating operation | movement of the slave in 5th Embodiment. It is a flowchart for demonstrating operation | movement of the master unit in 5th Embodiment. It is a block diagram which shows the other specific structural example of the slave in 5th Embodiment. It is a circuit diagram which shows the specific circuit example of the power supply monitoring part for inputs mounted in the slave in 5th Embodiment.

Explanation of symbols

10 PLC unit 11 Master unit 12 Field network 13 Mix slave 13a Transmission / reception circuit 13b MPU
13b 'Internal volatile memory 13b "Processing unit 13c Output circuit 13d Input circuit 13e External nonvolatile memory 13f Timer (internal clock)
14 Actuator 14a Moving body 15 Sensor 16a First sensor 16b Second sensor 20 OUT slave 21, 21 ', 21 "IN slave 30 Master unit 32 Field network 33 Slave 33a Voltage monitoring unit 33b Maximum value / minimum value holding unit 33c Current value storage unit 33d Monitoring voltage storage unit 33e Comparison unit 33f Alarm status storage unit 33g Communication control unit 34 Input / output device 35 Network power supply device 36 Network configurator 36a Input unit 36b Communication control unit 36c Display unit 37 Display screen 40 Master unit 42 Field Network 43 Slave 43a Input / output device power supply monitoring unit 43a ′ Input power supply monitoring unit 43b Input unit 43c Communication control unit 43d Short circuit protection circuit 44 Input / output device 44a Input device (sensor)
44b Output device (valve)
45 Input / output device power supply 45a Input power supply 45b Output power supply 46 Monitor 47 Network power supply 51 Resistor 52 Photocoupler 52a Light emitting diode 52b Light receiving transistor 53 Pull-up resistor 54 CPU

Claims (2)

A programmable controller that executes a user program for controlling the control device, a master unit that is connected to the programmable controller and has a communication function, and a control device is connected to the master unit via the network. A plurality of slaves that serially communicate OUT data; a network configurator that is connected to a network between the master unit and the slave; and a network power supply device. The network power supply device supplies power to the slave through the network. A network power supply monitoring system in a network system for supplying
At least one slave of the plurality of slaves is
Voltage monitoring means that operates with a network power supply supplied via a network and measures a supply voltage of the network power supply;
The measured value measured by the voltage monitoring means is compared with a reference value that is a criterion for determining whether or not the slave itself is likely to be inoperable, but the measured value is below the reference value. And judgment means for outputting alarm status,
Alarm status storage means for storing the alarm status output by the determination means;
Communication control means for outputting the alarm status stored in the alarm status storage means to the network configurator via a network;
Storage means for storing at least one of the maximum value, the minimum value, and the current value of the measurement values measured by the voltage monitoring means,
A slave having a function of outputting the measurement value information stored in the storage means and the reference value to the network configurator via a network;
The network configurator displays the alarm status, the measured value information, and the reference value acquired from the slave.   2. The network power supply monitoring system according to claim 1, wherein the display in the network configurator displays at least information of the measured value on a graph and displays the reference value on the graph.

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