CN105629923B - Controller and its control method - Google Patents

Abstract

The present invention provides a controller composed of a CPU module and a remote IO module, which reliably and selectively executes a control operation at the time of an abnormality according to an abnormal factor, thereby realizing a highly reliable controller. The controller of the present invention is equipped with: a CPU module having an abnormal state detection unit for detecting abnormal operation of the module, and performing program control on a plurality of equipment machines in the above-mentioned factory; and a plurality of remote IO modules connected through a serial transmission path The above-mentioned CPU module is connected in a chain, and the digital data transmitted from the above-mentioned CPU module is converted and output to the above-mentioned equipment. When the above-mentioned CPU abnormality is notified, all the above-mentioned equipment devices are controlled to be in a stopped state differently from the control based on the above-mentioned digital data.

Description

Controller and its control method

technical field

The present invention relates to a controller for automatically controlling plant equipment and the like.

Background technique

As a controller that performs automatic control, there is a system that connects a CPU (Central Processing Unit: central processing unit) module and a plurality of remote IO (Remote Input/Output: remote input/output) modules with a transmission cable. In this structure, the CPU module executes the control program for automatic control and outputs digital data DO (Digital Output data), and the remote IO module converts the digital data DO received from the CPU module into a factory output signal and converts it Output to the operation terminal of the factory equipment.

This remote IO type controller has the advantage of being able to realize the control of a plurality of distributed factory equipment at a space-saving and low-cost.

For example, the above-mentioned controller can be applied to a water and sewage plant composed of a plurality of devices for plant control. Each piece of equipment in a water and sewage factory is composed of a plurality of machines, and each machine is equipped with an operation terminal. By outputting a factory output signal to the operation terminal from the outside, it is possible to operate and stop the machine. The factory output signal is appropriately output from the controller or manual operation device to the operation terminal, so as to realize the operation of the single machine and the operation of the whole factory.

Misoperation or stoppage of the controller of the sewer factory may cause tap water stoppage, city flood, etc., thereby threatening life and property. Therefore, continuous and stable operation for 24 hours is required for the controller.

As above, high reliability is required for controllers for water and sewage plants.

When the controller detects an abnormality, in order to prevent malfunction of the plant, it is necessary to implement an emergency stop or operate the plant while maintaining the state before the abnormality was detected, stop part of the equipment and operate the plant with reduced functions, or Switch to manual operation for operation, etc.

In particular, when an abnormality of the CPU module, which has the highest risk of abnormality of the controller, is detected, it is necessary to avoid the risk of erroneous output of digital data DO due to CPU malfunction, and urgently stop the factory.

In addition, high-voltage electrical equipment, induction motors, inverters, and other equipment that become noise sources are installed in water and sewage plants. Therefore, when remote IO modules are used, there may be problems with transmission cables that connect the CPU module and remote IO modules due to noise overlap. Potential for temporary transmission anomalies.

Conventionally, in view of the above-mentioned circumstances, when an abnormality of the controller is detected, a technique of controlling the power supply to the external load has been proposed (for example, refer to Patent Document 1).

According to the technology disclosed in Patent Document 1, an abnormality is detected by the pulse output output from the main program and an external circuit timer composed of a relay and a timer. failsafe function.

In addition, the following IO unit is disclosed in Patent Document 2. By providing an output terminal for abnormality inspection of the MPU 11, the output state of the output terminal of the IO unit at the time of abnormality inspection becomes a state in which the connected IO device is not activated, so that it can be detected in advance. Are there any malfunctions or abnormalities?

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 9-185403

Patent Document 2: Japanese Patent Laid-Open No. 2008-310389

Contents of the invention

The problem to be solved by the invention

According to the technology disclosed in the above-mentioned Patent Document 1, the pulse output is monitored by a combination of an on-delay timer and an off-delay timer, so at least two program cycles or more are required for abnormality detection waits from when an abnormality occurs to when an abnormality is detected. time. Therefore, there is a problem that it is impossible to prevent erroneous output to the factory due to CPU malfunction during the abnormality detection waiting time.

In addition, according to Patent Document 1, even if an abnormality occurs in any part of the CPU module, remote IO module, main program, transmission, and external circuits, all the same abnormalities are detected, so there is a risk that even if a CPU abnormality is detected, the degree of risk is particularly high. There is a problem that the digital data DO cannot be reliably and immediately disconnected even when the abnormality factor is high when it is detected.

In addition, there is a problem that the controller composed of the CPU module and the remote IO module cannot detect the necessary transmission abnormality, that is, it cannot select and set the abnormality control operation when the transmission abnormality is detected.

According to the technology disclosed in the above-mentioned Patent Document 2, although the presence or absence of failure and abnormality of the IO unit can be detected in advance, there is a problem that the failure detection during actual operation is not considered, and the failure of the CPU unit and main unit of the PLC is not considered. .

As described above, in the techniques disclosed in Patent Documents 1 and 2, the reliability required for a controller for water and sewage cannot be realized.

method used to solve the problem

The present invention has been made in view of the above-mentioned actual situation, and the object is to provide a controller composed of a CPU module and a remote IO module, which can reliably and selectively execute abnormality according to abnormal factors such as CPU abnormality and transmission abnormality. Timely control action, so that a highly reliable controller can be realized.

In order to solve the above-mentioned problems, a controller for controlling equipment in a factory according to the present invention includes: a CPU module having an abnormal state detection unit for detecting abnormal operation of the module, and program-controlling a plurality of equipment in the factory; and A plurality of remote IO modules are daisy-chain-connected to the CPU module through a serial transmission path, and convert digital data transmitted from the CPU module to output to the equipment device, and the CPU module detects an abnormality in the abnormal state detection part When operating, the remote IO module is notified of CPU abnormality, and when the remote IO module is notified of the CPU abnormality, unlike the control based on the digital data, all of the equipment devices are stopped.

In addition, for the controller of the present invention having a CPU module and a remote IO module controlling a plurality of equipment in a factory, the CPU module and the remote IO module are connected through a serial transmission path and a CPU status signal, The serial transmission path daisy-chain connects the CPU module and the remote IO module and transmits control information, and the CPU status signal daisy-chain connects the CPU module and the remote IO module and transmits the CPU from the CPU module to the remote IO module. abnormal.

In addition, the control method of the present invention has a CPU module and a remote IO module that controls at least one equipment in the factory, and controls a plurality of equipment in the factory. The step of performing the abnormal operation of the CPU module controlled by the program and outputting a signal indicating the abnormal state in the CPU state signal; and setting the above-mentioned remote IO of each operation terminal of the above-mentioned plurality of equipment in correspondence with the digital data DO notified from the CPU module A step of setting all of the operation terminals to a predetermined state by the module based on a signal indicating an abnormal state of the CPU state signal.

The effects of the present invention are as follows.

According to the present invention, the reliability of the controller can be improved.

Description of drawings

Fig. 1 is a configuration diagram of a controller of a water and sewage plant.

FIG. 2 is a diagram showing a configuration example of a CPU module.

FIG. 3 is a sequence diagram illustrating abnormality detection processing of a control program.

FIG. 4 is a diagram showing a configuration example of a remote IO module and equipment.

FIG. 5 is a diagram showing a configuration of a CPU abnormality control unit.

FIG. 6 is a diagram showing the configuration of an IO output unit of a remote IO module.

FIG. 7 is a diagram showing an example of a sequence chart of a CPU abnormality control unit.

FIG. 8 is a diagram showing another configuration of a remote IO module.

FIG. 9 is a diagram showing an example of a timing chart of digital data DO output from a remote IO transfer unit.

Fig. 10 is a flowchart in the case of performing program processing on the operation of the remote IO module.

FIG. 11 is a flowchart of CPU exception processing performed asynchronously.

FIG. 12 is a diagram showing an example of a water delivery factory.

in:

1—controller; 2—CPU module; 3, 3a, 3b, 3c—remote IO module; 4, 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i—equipment machine; 5—serial transmission Path; 6—CPU status signal; 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i—machine connection cables.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1

This embodiment will be described by taking raw water from a reservoir or a river as an example, such as a water purification plant, which manufactures tap water by sedimentation of chemicals, sand filtration, and injection of chlorine gas.

Water purification plants and other sewage plants are composed of raw water pump equipment, high-voltage power receiving equipment, emergency generator equipment, chemical injection equipment, sedimentation tank equipment, filter tank equipment, chlorine gas injection equipment, water delivery pump equipment, drainage equipment, etc. Furthermore, these devices include control devices such as pumps, motors, valves, circuit breakers, and engines, and detection devices such as water level gauges, flow meters, and water quality sensors.

In the control device described above, a status contact for outputting the operating state of the device to the outside is provided. Here, in the operating state of the machine, there are on-off states such as pump operation or stop, valve fully open, fully closed, or slightly open, circuit breaker on or off, and machine failure state.

The electrical specification of the state contact is, for example, a binary output in which the pump is in an electrically conductive state when it is running, and is in an isolated state when it is stopped.

In addition, the above detection equipment has an analog output terminal for converting numerical information output by sensors such as current, voltage, flow rate, water level, water pressure, and opening into an analog signal of voltage or current and outputting it to the outside.

In addition, the control device described above is provided with an operation terminal for externally operating the operation of the device. Make the operation terminals into the state of electrical conduction and insulation, so as to control the operation and stop of pumps and motors, the opening and closing of valves and valves, the on and off of circuit breakers and capacitors, etc. For example, if the operating terminal of the pump is electrically conducted from the outside, the pump will operate, and if it is in an isolated state, the pump will stop. The above-mentioned operation terminal is sometimes also an analog input terminal for inputting an analog signal from the outside. At this time, the opening degree, rotation speed, etc. of the machine are controlled according to the signal of the analog input terminal.

The detectors mentioned above may also have analog input terminals.

FIG. 1 is a block diagram of a controller of a water and sewage plant such as a water purification plant equipped with the above-mentioned control equipment.

The controller 1 is composed of a CPU (Central Processing Unit) module 2 and a plurality of remote IO (Remote Input/Output) modules 3 a, 3 b, and 3 c (hereinafter, collectively referred to as remote IO modules 3 ).

The CPU module 2 and the plurality of remote IO modules 3 are daisy-chain-connected via a multi-drop serial transmission line 5 such as RS-485. Moreover, the sequence program operating on the CPU module 2 accesses the remote IO module 3 via the serial transmission path 5, thereby controlling a plurality of equipment devices 4a, 4b, 4c, ... 4i (hereinafter collectively referred to as equipment devices) including control devices. 4).

In the system structure diagram of FIG. 1 , a structure with multiple remote IO modules 3 is shown, but a structure with one CPU module 2 and one remote IO module 3 is also possible.

In the following description, the digital data transmitted between the CPU module 2 and the remote IO module 3 via the serial transmission path 5 will be referred to as digital data DI (DI: Digital Input data) for input and output of 1-bit structure. Digital data DO (DO: Digital Output data), analog input data AI (AI: Analog Inputdata) of word or long word structure, analog output data AO (AO: Analog Output data), pulse input data PI (PI: Pulse Inputdata) etc.

The remote IO module 3 is connected to the status contacts, operation terminals, analog input terminals, and analog output terminals of a plurality of equipment machines 4 via machine connection cables 7a, 7b, 7c, ... 7i (hereinafter collectively referred to as machine connection cables 7). . The electrical specifications of the machine connection cable 7 have voltage outputs such as AC100V, AC200V, DC24V, DC48V, etc., and have a conduction or insulation state. Or 4 ~ 20mA, 1 ~ 5V and other analog signals.

The status contacts, operation terminals, analog input terminals, and analog output terminals of the equipment device 4 are accessed from the remote IO module 3 via the equipment connection cable 7 , and the CPU module 2 controls the equipment device 4 through the remote IO module 3 .

More specifically, the state of the status contact of the equipment equipment 4 is input to the remote IO module 3 via the equipment connection cable 7 as a signal from the equipment equipment. The input state of the status contact of the equipment device 4 is converted into digital data DI transmitted from the remote IO module 3 to the CPU module 2 . Specifically, when the status contact of the equipment 4 is in the conductive state, DI is converted to "1", and when it is in the isolated state, DI is converted to "0". The digital data DI of the status contacts of the converted equipment machine 4 are transmitted from the remote IO module 3 to the CPU module 2 . Moreover, when the equipment 4 outputs a voltage or current level, it AD-converts the state of the analog output terminal of the equipment 4 to form analog input data AI, and transmits it from the remote IO module 3 to the CPU module 2 .

When the digital data DO is transmitted from the CPU module 2 , the remote IO module 3 drives the device connection cable 7 into a conduction state or an insulated state, thereby controlling the operation terminal of the equipment device 4 . Specifically, the device connection cable 7 is driven into a conduction state when DO is "1", and is driven into an insulated state when DO is "0".

In addition, the remote IO module 3 performs DA conversion on the analog output data AO to form an analog signal, and outputs it to the analog input terminal of the equipment device 4 .

In FIG. 1 , three equipment devices 4 are connected, but 8 to 64 equipment devices 4 can be connected to one remote IO module 3 . A plurality of I/O modules 3 are connected to the CPU module 2 . Usually, the total number of state contacts, operation terminals, analog input terminals, and analog output terminals for input and output of one controller is tens to thousands of points.

The machine connection cables 7 are laid for each status contact, operation terminal, analog input terminal, and analog output terminal, and the number is tens to thousands. Especially in large-scale systems, the laying of the machine connection cable 7 becomes difficult. Therefore, by applying the remote IO module 3 and installing the remote IO module 3 near the equipment 4, it is easy to lay the equipment connection cable 7, but it is necessary to deal with the mistransmission of the serial transmission path 5.

In addition, it is necessary to deal with the abnormal operation of the remote IO module 3 with respect to the CPU module 2 .

In the controller 1 of this embodiment, transmission errors and CPU abnormal operations are dealt with in the following manner.

The CPU module 2 executes the control program based on the digital data DI and the analog input data AI, and outputs the digital data DO and the analog output data AO as the execution result. At this time, the CPU module 2 of this embodiment monitors the status of hardware and programs to detect abnormal operation, and outputs whether there is abnormality in the CPU status signal 6 .

In addition, the remote IO module 3 has an error detection mechanism of the serial transmission path 5 such as a parity error, and when a transmission error is detected, the DO of each equipment device 4 is set to "0" (insulated state) or remains in the state before the error is detected. status.

In addition, when the CPU state signal 6 indicates that the CPU is abnormal, the remote IO module 3 drives the operation terminals of all the equipment devices 4 to an isolated state regardless of the state of DO.

Hereinafter, the configuration for handling transmission errors and CPU operation abnormalities will be described in detail.

FIG. 2 is a diagram showing a configuration example of the CPU module 2 . The CPU module 2 has a CPU 21 , a memory 22 , a CPU transmission unit 23 , an abnormal state detection unit 25 , and an abnormal state output unit 26 , and is connected to each other through a CPU system bus 24 . The memory 22 is RAM (Random Access Memory: random access memory) etc., and the control program 221 and the register 222 are arrange|positioned.

The CPU transmission unit 23 performs serial communication with the remote IO module 3 via the transmission cable 5 in a predetermined cycle corresponding to the processing of the control program 221 , and transmits and receives digital data DI, digital data DO, and the like. In addition, the CPU transfer unit 23 transmits and receives digital data DI and digital data DO to and from the register 222 via the system bus 24 to align the digital data of the remote IO module 3 and the register 222 (referred to as refresh processing).

The control program 221 is a program for sequence control and cycle control of the equipment 4, and the register 222 stores digital data DI, digital data DO, analog input data AI, analog output data AO, initial data of the control program, calculation data, and the like.

In addition, the control program 221 is periodically executed by the CPU 21. After the remote IO module 3 converts the content of the status contact of the equipment 4 into digital data DI, it is stored in the register 222 via the CPU transmission unit 23, and becomes the content of the control program 221. enter.

The control program 221 uses the digital data DI of the register 222 as an input, executes program operations such as logic operations and numerical operations, and outputs digital data DO as an execution result. And the digital data DO output to the register 222 by the control program 221 is sent to the remote IO module 3 via the CPU transmission part 23, and the operation terminal of the equipment 4 is set in a predetermined cycle.

FIG. 3 is a sequence diagram illustrating abnormality detection processing of the control program 221 .

The control program 221 repeatedly executes processing in a control cycle of, for example, 50 ms, 100 ms, 200 ms, or the like.

This processing is composed of refresh processing of the remote IO module 3 and the digital data of the register 222, and program operation. The result of the program operation stored in the register 222 is sent to the remote IO module 3 in the refresh process of the IO module in the next cycle.

When an abnormal operation of the CPU 21 and the memory 22 or a program abnormality of the control program 221 occurs, the program operation may not be completed within a predetermined time.

The abnormal state detection unit 25 monitors the processing cycle of the control program 221, and determines that the CPU is abnormal when the processing cycle of the control program 221 exceeds a predetermined monitoring time.

More specifically, a monitoring timer that overflows within a predetermined monitoring time is provided in the abnormal state detection unit 25 , and timer initialization and timer activation are performed at the start of the control program 221 . When the control program 221 operates normally, the watchdog timer does not overflow. However, when the process of the control program 221 is delayed and the watchdog timer overflows, it is determined that the operation of the CPU is abnormal.

In addition, the refresh processing of the IO module and the control program are independently executed, and the processing cycle of the refresh processing of the IO module and the control program is monitored. If the processing cycle of any one exceeds the specified monitoring time, it can also be judged as the operation of the CPU. abnormal. In addition, there may be a plurality of control programs.

In addition, the abnormal state detection unit 25 in FIG. 2 may detect hardware abnormalities such as ROM total error and memory bit error, and detect software abnormalities such as OS abnormality and control program abnormality through exception processing of illegal command execution.

The abnormal state output unit 26 notifies the plurality of remote IO modules 3 of the abnormal state of the CPU module 2 detected by the abnormal state detection unit 25 through the CPU state signal 6 . Therefore, a differential serial interface such as RS-485 capable of multi-station connection is used for the CPU state signal 6 in the same way as the serial transmission line 5 .

The serial transmission line 5 transfers data at predetermined intervals, but if an abnormality is detected, the CPU status signal 6 immediately outputs the abnormal status of the CPU module 2 .

As above, by providing the CPU status signal 6 separately from the serial transmission path 5, the abnormal status of the CPU can be communicated asynchronously regardless of the operation of the CPU transmission unit 23 of the CPU module 2, so that the abnormal status of the CPU can be quickly communicated. announcement of.

In addition, the CPU status signal 6 only needs to be able to notify the CPU of abnormality, so the communication capacity can also be small, and the communication rate can be lower than that of the serial transmission line 5 . The data reliability of the transmission of the CPU status signal 6 can thus be increased.

In addition, the abnormal state output unit 26 may include a CPU state contact for converting the state data detected by the abnormal state detecting portion 25 into a signal for driving the CPU state signal 6 for external output. At this time, the CPU state contact is constituted by, for example, a semiconductor relay, an electromagnetic relay, or the like. If the status data indicates that the CPU is normal, the CPU status contact can also be in a conducting state, and if the status data is that the CPU is abnormal, then the CPU status contact can also be in an insulated state.

At this time, when the power supply to the CPU module 2 is stopped, the CPU state contact transitions to the insulated state, so the stop of the power supply is also output as a CPU abnormality.

More specifically, there are voltages such as AC100V, AC200V, DC24V, DC48V, etc., to form a contact specification in a conductive state or an insulated state, so that the CPU status signal 6 is, for example, a 2-core cable, so that it can be ground without being affected by external noise. The presence or absence of an abnormal state of the CPU is reliably output from the CPU module 2 to the remote IO module 3 .

Alternatively, a current source of 4 to 20 mA may be provided, and the presence or absence of current may be made into a contact specification, and the state of current flow may be present when the CPU is normal.

FIG. 4 is a diagram showing a configuration example of the remote IO module 3 and the equipment 4 .

The remote IO module 3 has a remote IO transmission unit 31 , an IO input unit 36 , an IO output unit 34 , and a CPU abnormality control unit 35 , and is connected to each other through a system bus 33 . In addition, the IO input unit 36 is connected to the state contact 41 of the control device 42 of the equipment device 4 through the device connection input cable 7-2, and the IO output mechanism 34 is connected to the control device 42 of the device device 4 through the device connection output cable 7-1. Operation terminal 40 is connected.

Here, the IO input unit 36, the IO output unit 34, and the CPU abnormality control unit 35 surrounded by the dotted line in FIG. For DO correspondence, it becomes a structure including 16 IO input units 36 , IO output units 34 , and CPU abnormality control unit 35 .

The remote IO transmission unit 31 executes serial transmission via the CPU module 2 and the serial transmission path 5, and sends and receives digital data DI, DO. Here, the digital data to be serially transmitted is constituted by, for example, 16 DIs as 1 word, or 16 DOs as 1 word.

The remote IO transmission unit 31 receives the digital data DI corresponding to the state of the status contact 41 from the IO input unit 36 via the system bus 33 , and converts the digital data into words for transmission to the CPU module 2 .

Also, the remote IO transmission unit 31 extracts the digital data DO transmitted from the CPU module 2 and outputs the digital data DO to the IO output unit 34 via the CPU abnormality control unit 35 connected to the system bus 33 .

A CPU state signal 6 is connected to the CPU abnormality control unit 35 to notify the normal or abnormal state of the CPU module 2 . For the IO output that the remote IO module 3 possesses, the CPU abnormal control part 35 performs calculation between the normal or abnormal state of the CPU module 2 and the digital data DO input from the remote IO transmission part 31, and sends the calculation result to the IO output part. 34 outputs.

In detail, control is performed as follows. When notifying the CPU module 2 of a normal state, the IO output unit 34 outputs a state corresponding to the digital data DO, and when notifying the CPU module 2 of an abnormal state, the IO output unit 34 Output insulation status.

The IO output unit 34 is connected to the operation terminal 40 of the equipment 4 via the equipment connection output cable 7 - 1 , and notifies the operation terminal 40 of the equipment 4 of the conduction state or the insulation state according to the setting of the CPU abnormality control unit 35 . Thus, the equipment 4 is controlled.

The IO input unit 36 is connected to the state contact 41 of the equipment device 4 via the device connection input cable 7 - 2 to obtain the conduction state or the insulation state of the state contact 41 . Then, when the state contact 41 is in the conduction state, the digital data DI is set to "1", and when the state contact 41 is in the insulated state, the digital data DI is set to "0". The set digital data DI is notified to the CPU module 2 via the remote I/O transmission unit 31 .

FIG. 5 is a diagram showing the configuration of the CPU abnormality control unit 35 .

The CPU abnormality control unit 35 includes a first input circuit 351 , a second input circuit 352 , and a logical operation circuit 353 .

The first input circuit 351 is connected to the abnormal state output unit 26 of the CPU module 2 via the CPU state signal 6 , thereby converting the signal level of the CPU state signal 6 into a TTL (Transistor TransistorLogic: Transistor-Transistor Logic) level. For example, the CPU state signal 6 is converted to a low level when indicating an abnormal state of the CPU module 2 , and is converted to a high level when indicating a normal state of the CPU module 2 .

The second input circuit 352 is connected to the system bus 33 to convert the digital data DO received by the remote IO transmission unit 31 into a TTL level. For example, when the digital data DO is "0", it transitions to a low level, and when the digital data DO is "1", it transitions to a high level.

The logic operation circuit 353 is, for example, a logic circuit constituted by TTL, and performs logic operations of signals from the first input circuit 351 and the second input circuit 352, thereby outputting a control output signal. The control output signal is high level when the logic is established, and is low level when the logic is not established.

The logical operation circuit 353 of the embodiment includes an AND circuit, and outputs a control output signal as follows.

When the CPU state signal 6 represents the normal state of the CPU module 2, and the digital data DO is "1", the output of the first input circuit 351 becomes a high level, and the output of the second input circuit 352 also becomes a high level, As a result of the logical product of the logical operation circuit 353 , a high level of logical establishment is output as a control output signal.

When the CPU state signal 6 represents the normal state of the CPU module 2, and the digital data DO is "0", the output of the first input circuit 351 becomes a high level, the output of the second input circuit 352 becomes a low level, and the logic As a result of the logical product of the arithmetic circuit 353 , a low level that is logically false is output as a control output signal.

In the case where the CPU state signal 6 represents the abnormal state of the CPU module 2, even if the digital data DO is any one of "1" or "0", the result of the logical product of the logic operation circuit 353 will be a low level of logic failure. The output is a control output signal.

FIG. 6 is a diagram showing the configuration of the IO output unit 34 of the remote IO module 3 .

The IO output unit 34 is composed of a relay circuit 341 and an output terminal 342 .

The relay circuit 341 is constituted by, for example, a semiconductor relay, an electromagnetic relay, etc., and performs switching of the circuit on the output side according to the control output signal of the CPU abnormality control unit 35 . For example, when the control output signal becomes high level, the relay is turned on, and when the control output signal becomes low level, the relay is turned off.

The output terminal 342 is connected to the operation terminal 40 of the equipment device 4 through the equipment connection output cable 7 - 1 , and the operation terminal 40 is placed in a conduction state or an insulated state through the relay circuit 341 .

FIG. 7 is a diagram showing an example of a timing chart of the CPU abnormality control unit 35 , and shows the relationship among the CPU state signal, digital data DO, and control output signal.

When the CPU state signal 6 indicates a normal state, if the digital data DO is "1", the control output signal outputs a high level, and if the digital data DO is "0", the control output signal outputs a low level. As a result, a control output signal corresponding to the value of the digital data DO is output, and the operation terminal 40 of the equipment device 4 is controlled to be in a conductive state or an insulated state.

On the other hand, when the CPU state signal indicates an abnormal state, the control output signal outputs a low level regardless of whether the digital data DO is "1" or "0". Therefore, when the CPU state signal indicates an abnormal state, the operation terminal 40 of the equipment device 4 is controlled to be in an insulated state.

As described above, the CPU abnormality control unit 35 has been described as a structure corresponding to 1 point of digital data DO, but in the case of a structure corresponding to 16 points of digital data DO of the remote IO module 3, it becomes equipped with 16 diagrams. The second input circuit 352 of 5 has a structure in which 16 AND gate circuits 353 are provided, and 16 control output signals are output from the AND gate circuits 353 . And, when the abnormal state of the CPU module 2 is notified by the CPU state signal 6, all the 16 IO output parts 34 control the operation terminal 40 of the connected control device 4 to an insulated state.

As shown in Figure 1, when the controller 1 has multiple remote IO modules 3, the CPU status signal 6 is daisy-chain connected to multiple remote IO modules 3, so the abnormal status of the CPU module 2 is notified to all Remote IO module 3. In each remote IO module 3, the above-mentioned processing is performed, and the operation terminal 40 of the connected control device 4 is controlled to be in an isolated state. Thereby, all the equipments controlled by the controller 1 can be stopped.

Embodiment 2

FIG. 8 is a diagram showing another configuration of the remote IO module 3 .

The remote IO module 3 has a remote IO transmission part 31, a transmission abnormality control part 32, a plurality of IO input parts 36, an IO output part 34, and a CPU abnormality control part 35 arranged for each equipment machine 4 connected, and passes through a system bus 33 interconnected. Also, the IO input unit 36 is connected to the status contact 41 of the equipment device 4 through the equipment connection input cable 7 - 2 , and the IO output unit 34 is connected to the operation terminal 40 of the equipment equipment 4 through the equipment connection output cable 7 - 1 .

The remote IO module 3 shown in FIG. 4 is different from the remote IO module 3 of this embodiment in that it has the transmission abnormality control unit 32 , and the following description will focus on the differences.

The abnormal transmission control part 32 monitors the transmission status of the serial transmission path 5 connecting the remote IO module 3 and the CPU module 2 in each control cycle via the remote IO transmission part 31, and controls the remote IO transmission part 31 when abnormal transmission is detected. , and change the digital data DO according to a preset change rule.

Here, the transmission abnormality detected by the transmission abnormality control unit 32 is detected by a disconnection such as a cable disconnection, a timeout detection as a state in which transmission and reception has not been completed within a predetermined time, and an error detection such as a CRC error or a parity error of the transmitted digital data. to judge.

When the transmission abnormality control unit 32 detects transmission abnormality in each control cycle, the change rule for changing the digital data DO is, for example, rewriting DO to "0" (returning to zero), and maintaining (holding) the digital data before the abnormality is detected. DO et al.

This change rule can be set for each bit of the digital data DO, in other words, for each equipment device 4 to be controlled. Therefore, in the remote IO module to which the equipment 4 having a plurality of operation terminals is connected, the change rule is commanded and set by the CPU module 2 for each digital data DO.

The digital data DO changed when the transmission is abnormal by the remote IO transmission unit 31 is sent to the CPU abnormality control unit 35 .

In the CPU abnormality control unit 35 , as described above, the digital data DO is changed according to the state of the CPU state signal 6 , and a control output signal is output to the IO output unit 34 . This control output signal is switched to a conductive state or an isolated state by the IO output unit 34 and notified to the operation terminal 40 of the equipment device 4 .

FIG. 9 is a diagram showing an example of a timing chart of digital data DO output from the remote IO transfer unit 31 . The relationship between the output of the CPU abnormality control unit 35 is shown in accordance with the digital data DO input from the CPU module 2 , the presence or absence of transmission abnormality, and the digital data change rule at the time of transmission abnormality.

When the transmission abnormality of the transmission cable 5 is not detected by the transmission abnormality control unit 32, the digital data DO is not changed from the remote IO transmission unit 31 to the CPU abnormality control unit 35 regardless of the setting of the change rule of the digital data DO. On the other hand, it is outputted, and if there is no CPU abnormality, it is outputted as it is.

On the other hand, when a transmission abnormality is detected, the digital data DO output to the CPU abnormality control unit 35 differs depending on the setting of the change rule of the digital data DO. If the rule is to hold the setting, the digital data DO is changed to a value ("1" in FIG. 9 ) before the transmission abnormality is detected, and output. If the rule is zero, the digital data DO is changed to "0" and output. And if there is no CPU abnormality, the changed digital data DO is output.

As described above, by setting change rules for digital data DO for each equipment device 4 , it is possible to change the response method when an error occurs according to the importance of the equipment device 4 , thereby improving the reliability of the system.

FIG. 10 is a flowchart in the case of performing program processing on the operation of the remote IO module 3 . The flow of FIG. 10 operates in each of the plurality of remote IO modules 3 .

First, it is determined whether the digital data DO of the own remote IO module 3 has been received (S901). If the digital data DO of the own remote IO module 3 has not been sent from the CPU module 2, it waits for reception (No of S901).

When the above-mentioned digital data DO is received (YES in S901), it is determined whether there is a transmission abnormality at the time of reception (S902). Specifically, determination of transmission abnormality is performed by parity check, CRC code, sum check, and the like.

When there is no abnormality (No in S902), the digital data DO is normally transmitted, and the received DO is temporarily saved for the transmission abnormality processing described later (S909), and the process proceeds to S906.

When there is a transmission abnormality (YES in S902), the digital data DO is changed as follows.

First, determine the type of the set correction rule (S903), and if it is "return to zero" ("reset to zero" in S903), rewrite the digital data DO to zero (S904), and proceed to S906.

If it is "Hold" in S903 ("Hold" in S903), the digital data DO is rewritten to the value of DO that was normally transmitted before being temporarily saved in S909 (S905). In other words, after rewriting to the value before the abnormality is detected, it proceeds to S906.

In S906 , it is determined whether or not a CPU abnormality notification has been detected from the CPU module 2 . When a CPU abnormality is detected (YES in S906), the digital data DO is unconditionally rewritten to zero (S907), and the process proceeds to S908.

When the notification of CPU abnormality is not detected in S906 (NO of S906), it progresses to S908.

In S908, the digital data D0 is set in the IO output unit 34, and the conduction state or the insulation state is output according to the value of the digital data DO.

Through the above flow, the abnormal operation of the CPU module 2 and the transmission abnormality in the serial transmission line 5 are detected, and the digital data DO is changed, so that the abnormal control of the controller 1 can be prevented.

In addition, in order to quickly take countermeasures against the abnormality of the CPU module 2 , the processing at the time of occurrence of abnormality of the CPU module is performed asynchronously with the processing flow in FIG. 10 .

FIG. 11 is a flowchart of CPU exception processing performed asynchronously.

The processing in FIG. 11 is started by the received data interrupt of the CPU status signal 6, and it is preferable to increase the priority of the interrupt as much as possible.

In addition, since the processing content of S906, S907, and S908 of FIG. 11 is the same as FIG. 10, description is abbreviate|omitted here.

Embodiment 3

Next, a specific example of the change rule of the digital data DO processed by the transmission abnormality control part 32 is demonstrated using FIG. 12. FIG.

FIG. 12 is a diagram showing an example of a water transfer plant that pumps up the stored water in the pump well 8 and controls the target flow rate to flow out from the pipe 9 as effluent water.

The water delivery plant is composed of a pump well 8, piping 9, a constant speed pump 42a, an electric valve 42b for adjusting flow rate, and a flow meter 42c. And the flow rate of the outflow water discharged|emitted by the constant speed pump 42a is measured by the flow meter 42c, and is controlled by the electric valve 42b so that it may become a constant flow rate.

The water delivery factory connects the equipment machine 4a including the fixed speed pump 42a, the equipment machine 4d including the electric valve 42b, and the equipment machine 4g including the flowmeter 42c to the remote IO module 3a through machine connection cables 7a, 7d, 7e, and 7g. , 3b, 3c, and through the CPU module 2 for flow control. The remote IO modules 3 a , 3 b , 3 c are daisy-chain connected to the CPU module 2 through the serial transmission path 5 and the CPU status signal 6 .

Next, the functions of the equipment devices 4a, 4d, and 4g will be described.

The fixed-speed pump 42a of the equipment 4a is a specification with a constant rotational speed, discharges a constant flow rate during operation, and discharges a flow rate of zero when stopped. The equipment 4a includes an operation terminal 40a, and the pump operation is continued by making the operation terminal 40a electrically conductive, and the pump operation is stopped when the operation terminal 40a is in an insulated state.

The motorized valve 42b of the equipment 4d controls the discharge flow rate from the constant speed pump 42a by adjusting the opening and closing of the valve through forward rotation and reverse rotation of the motor. The valve opening is, for example, operated within a range of 0% to 100% of fully closed 0% and fully opened 100%. The setting of the valve opening degree is performed by controlling the operation time of the valve opening operation and closing operation.

Specifically, if the opening and closing actions are performed at a speed of 5% of the valve opening in 1 second, for example, if the opening action is maintained for 20 seconds in the fully closed state, the valve will be fully opened and the opening action will stop. On the contrary, in the fully open state, if the closing operation is maintained for 20 seconds, it will become a fully closed state, and the closing operation will stop.

The equipment 4d is equipped with an operation terminal 40b (opening action) and an operating terminal 40c (closing action). By making the operating terminals 40b and 40c in an electrically conductive state, the opening or closing action is continued, and if it is in an insulated state, the opening or closing action is made. The closing action stops.

The valve opening degree of the electric valve 42b of the equipment 4d can be controlled to a target opening degree by adjusting the time during which the operation terminal 40b or the operation terminal 40c is in the conduction state.

The flow meter 42c of 4 g of equipment instruments measures the outflow flow rate of outflow water.

The analog output terminal 43 of the equipment 4g converts the measured flow rate value into a current signal of 4 to 20 mA, and outputs it.

In the CPU module 2, the outflow flow rate of the analog output terminal 43 is obtained as the analog input data AI via the remote IO module 3c, and the operation and stop of the constant speed pump 42a are controlled and the electric valve is controlled so that the analog input data AI becomes the target flow rate. 42b's opening action and closing action control program.

The fixed-speed pump 42a records the operation instruction of running or stopping in the digital data DO through the control program, and sets it in the operation terminal 40a of the equipment 4a via the remote IO module 3a, thereby instructing running or stopping.

The electric valve 42b records the operation instructions of opening and closing operations in the digital data DO through the control program, and sets them in the operation terminals 40b and 40c of the equipment 4d via the remote IO module 3b to set the valve opening degree.

As described above, the remote IO modules 3a and 3b detect a transmission abnormality in the serial transmission line 5 that transfers the digital data DO, and change the digital data DO based on a predetermined change rule.

In the present embodiment, when a transmission abnormality is detected, the digital data DO is changed in the next change rule with respect to the constant speed pump 42a and the electric valve 42b.

In the remote IO module 3a, a change rule is formed to keep the digital data DO instructing the operation of the constant speed pump 42a in the setting state of the previous control cycle. In other words, the current operation or stop state of the constant speed pump 42a is maintained.

In the remote IO module 3b, a change rule is formed to reset the digital data DO indicating the opening and closing of the electric valve 42b to zero (no opening or closing). In other words, the current flow rate is maintained by stopping the valve opening and closing operations of the electric valve 42 b and fixing the valve opening.

As described above, the rules for changing the digital data DO when the transmission of the fixed-speed pump 42a and the electric valve 42b of the water delivery factory of the present embodiment are abnormal are set so as not to stop the water delivery in the control cycle when the transmission abnormality is detected. When the transmission is restored to normal, the control can be easily restarted.

The above-mentioned change rule is not limited to this, and can be appropriately determined according to the operation specification at the time of transmission abnormality.

However, in the controller 1 of the water delivery plant of the present embodiment shown in FIG. 12 , the CPU module 2 notifies the remote IO modules 3 a , 3 b , and 3 c of CPU abnormality through the CPU status signal 6 .

The remote IO modules 3a, 3b, and 3c notified of a CPU abnormality by the CPU state signal 6 set the digital data DO to "0" and set the operation terminals 40a, 40b, and 40c to an isolated state. In other words, since the constant speed pump 42a stops the pump operation, and the electric valve 42b stops the opening or closing operation, the outflow of the effluent water is stopped.

When a CPU abnormality is detected, it may take time until the recovery of the controller. Therefore, it is preferable to manually operate the constant speed pump 42 a and the electric valve 42 b in advance in order to discharge the effluent water.

Therefore, for example, a switching device is provided on the equipment connection cable 7a of the operation terminal 4a of the constant speed pump 42a, so that the signal from the remote IO module 3a and the signal from the manual operation device can be selected.

When the constant speed pump 42a stops due to CPU abnormality, the switching device switches to connect the operation terminal 4a of the constant speed pump 42a and the manual operation device. Then, the operation terminal 4a of the constant speed pump 42a is brought into conduction state by the manual operation device, and the pump operation is performed.

As described above, according to the present embodiment, when the controller 1 detects a fatal state such as an abnormality of the CPU module 2, the device connection output cable 7-1 is reliably insulated, thereby enabling all equipment The operation of the machine is stopped, so it is possible to prevent malfunctions in the factory.

In addition, according to this embodiment, by installing a simple logic circuit in the remote IO module without using a mechanism such as a high-performance CPU and laying only a signal cable for notifying the status of the CPU module, it is possible to reliably stop the operation of the factory when the CPU is abnormal. , and therefore there is an effect that security can be improved at low cost.

In addition, if the CPU module 2 is normal, when the transmission abnormality of the serial transmission path 5 is detected, the continuation or stop of the output to the control device can be selected and set, so it is possible to flexibly respond to the control even when an abnormality occurs. The importance of the target equipment and the effect of the operation policy.

In addition, the operation of all connected control devices is stopped only when a specific major abnormality factor such as CPU abnormality is detected, so that the utilization rate of automatic control operation is improved, and the burden of manual operation on the operator can be expected reduction.

The controller according to the present invention is not limited to the above-described embodiments, and can be appropriately modified within a range not departing from the gist of the present invention. Other embodiments of the controller according to the present invention will be listed below.

In the above-mentioned embodiment, although the remote IO module 3 has a structure with one DI and one DO, it may also be formed with a plurality of DIs and a plurality of DOs, and may also be formed with a plurality of AIs and AOs. , The structure of PI.

In addition, in the above-mentioned embodiment, although the status contact, the operation terminal, and the CPU status contact were made a contact, they may be a b contact or a c contact.

In addition, the controller 1 according to the above-described embodiment can also be applied to controllers of social infrastructure systems such as electric power, gas, transportation, and reservoirs, and controllers of industrial systems such as iron and steel, chemical, food, and logistics.

In addition, in addition to storing information such as programs and data for realizing various functions in RAM (Random Access Memory: Random Access Memory), it can also be stored in recording devices such as SSD (Solid State Drive: Solid State Drive), IC (Integrated Circuit: Integrated Circuit) circuit) card, SD (Secure Digital: Secure Digital) card, DVD (Digital Versatile Disc: Digital Versatile Disc) and other recording media.

In addition, the configurations, functions, CPU, memory, and system bus of each unit related to the above-described embodiments can be realized in whole or in part by hardware designed as an integrated circuit.

In addition, in the drawings explaining the embodiment, only control lines and information lines considered necessary for explanation are shown, and it is not necessarily limited to show all control lines and information lines in terms of products. In fact, it is also conceivable that substantially all structures are connected to each other.

Claims (10)

1. A kind of controller, it controls the equipment machine of factory, and above-mentioned controller is characterized in that, possesses: A CPU module, which has an abnormal state detection unit for detecting abnormal operation of the module, and performs program control on a plurality of equipment machines of the above-mentioned factory; and a plurality of remote IO modules, which are daisy-chain connected to the above-mentioned CPU module through a serial transmission path, and convert digital data transmitted from the above-mentioned CPU module to output to the above-mentioned equipment machine, The CPU module notifies the remote I/O module of the CPU abnormality when the abnormal operation is detected by the abnormal state detection unit, When the remote I/O module is notified of the abnormality of the CPU, unlike the control based on the digital data, all the above-mentioned devices are stopped, The remote IO module has a transmission abnormality control unit that detects a transmission abnormality of the serial transmission path and changes digital data, The transmission abnormality control unit changes the digital data based on a predetermined change rule for each of the plurality of connected equipment devices when a transmission abnormality is detected. 2. The controller according to claim 1, characterized in that, The CPU abnormality is notified from the CPU module to the remote IO module through a signal cable that daisy-chains the CPU module and the remote IO module differently from the serial transmission path. 3. The controller according to claim 1, characterized in that, The remote IO module calculates the logical product of the CPU abnormality and the digital data, and outputs the result of the logical product to the equipment device. 4. The controller according to claim 1, characterized in that, The above changing rule is to rewrite the digital data to "0" to return to zero, or to maintain the digital data before abnormal transmission is detected. 5. A controller having a CPU module and a plurality of remote IO modules controlling a plurality of equipment machines in a factory, the above-mentioned controller is characterized in that, The above-mentioned CPU module and the above-mentioned remote IO module are connected through a serial transmission path and a CPU status signal, The serial transmission path daisy-chain connects the above-mentioned CPU module and the above-mentioned remote IO module and transmits control information, The CPU status signal daisy-chain connects the above-mentioned CPU module and the above-mentioned remote IO module and transmits a CPU abnormality from the above-mentioned CPU module to the above-mentioned remote IO module, The remote IO module has a transmission abnormality control unit that detects a transmission abnormality of the serial transmission path and changes digital data, The transmission abnormality control unit changes the digital data based on a predetermined change rule for each of the plurality of connected equipment devices when a transmission abnormality is detected. 6. The controller according to claim 5, characterized in that, The aforementioned serial transmission path periodically transmits control information, The CPU status signal transmits CPU status information asynchronously with the serial transmission path. 7. The controller according to claim 6, characterized in that, The data amount of the CPU state information is smaller than the control information transmitted by the serial transmission path. 8. A control method, which is a control method of a controller, the controller has a CPU module and a plurality of remote IO modules controlling at least one equipment machine in the factory and controls a plurality of equipment machines in the factory, the above-mentioned control method Characterized by: A step of detecting the abnormal operation of the CPU module that performs program control on a plurality of equipment machines in the above-mentioned factory and outputting a signal indicating the abnormal state in the CPU state signal; The remote IO module that sets the operation terminals of each of the plurality of equipment corresponding to the digital data DO notified from the CPU module sets all the operation terminals to a predetermined value based on the signal indicating an abnormal state of the CPU status signal. the state of the step; and The above-mentioned remote IO module monitors the serial transmission path connecting the above-mentioned CPU module and the above-mentioned remote IO module within a predetermined control cycle, and when abnormal transmission is detected, the digital data DO notified from the above-mentioned CPU module is changed according to a predetermined change rule and set Follow the steps above to operate the terminals. 9. The control method according to claim 8, characterized in that, The timing at which the remote IO module sets the operation terminal corresponding to the digital data DO from the CPU module is different from the timing at which the operation terminal is set based on a signal indicating an abnormal state of the CPU state signal. 10. The control method according to claim 8, characterized in that, Compared with the step of changing the digital data DO notified from the CPU module according to a prescribed change rule and setting it in the operation terminal, the remote IO module preferentially processes the signal indicating an abnormal state of the CPU status signal to set the Procedure for operating terminals.