JP7621235B2 - Verification method and connection tool for replacing old sequencer with new sequencer - Google Patents

Description

This disclosure relates to a verification method and connection tool for replacing an old sequence controller that controls the operation of a plant with a new sequence controller.

In plants such as water purification plants, sewage treatment plants, and waste disposal equipment, a controller called a sequencer is used to control sequences (orders) to ensure smooth operation and management of the entire plant. By using a sequencer, it is possible to control the plant according to pre-determined conditions based on the state of input devices such as switches, sensors, timers, and counters.

For example, Patent Document 1 discloses an operation authentication system for plant equipment in which, when an operator approaches within a certain range of an operation panel C that operates the plant equipment, optical and radio wave transmission is performed between an authentication controller 1 arranged on the operation panel side and a tag T, the unique ID of the tag T is determined from an authentication database previously input to the controller 1 side to identify the position ID and tag ID, the operation authority of the operator is identified, etc., and based on this authentication result, a control sequencer 2 determines the operable range of the operation panel C and selects whether or not to grant the specific operator the authority to operate the operation panel C.

JP 2006-119860 A

However, with recent improvements in programmable controller functionality and the increasing complexity of plants, the verification work for newly introduced programmable controllers has become more complex and the verification time tends to increase. However, at the same time, it is often not always easy to increase the number of workers available for verification work. For this reason, it is possible to perform the verification work all at once during the day when workers are able to perform the work, but in order to complete the verification work during the daytime hours, there are cases where only important verification items have to be verified. This makes it difficult to reliably verify whether the plant is operating stably with the new programmable controller, and there is room for improvement in this regard.

The objective of this disclosure is to solve these problems, and to propose a verification method and connection tool for replacing an old PLC with a new PLC that can achieve both stable and continuous plant operation and reliable verification of the new PLC.

The verification method of the present disclosure includes:
A verification method for replacing an old sequence controller with a new sequence controller in a plant control system that operates a plant using a sequence controller, comprising:
The plant control system includes:
An old sequence controller that connects to the controlled device via the old sequence controller I/O module,
A new PLC that connects to the controlled equipment via a new PLC I/O module,
A temporary rack for accommodating the old sequencer;
a sequencer board housing either the old sequencer or the new sequencer;
a connection tool for connecting the old sequence controller to a control target device,
the connection tool includes a temporary terminal block that is detachably connected to the old sequence controller input/output module, a temporary adapter that detachably connects an equipment terminal block that is connected to a controlled equipment, and a connection cable that electrically connects the temporary terminal block and the temporary adapter to each other;
the device terminal block is detachably connectable to any one of the old sequence controller input/output module, the temporary adapter, or the new sequence controller input/output module;
The verification method includes:
an initial operation confirmation step of connecting the device terminal block to the old sequencer input/output module and controlling the plant by the old sequencer in the sequencer board;
a relocation step of moving and installing the old sequence controller installed on the sequence controller board on the temporary rack;
a post-relocation operation confirmation step of connecting the device terminal block and the temporary adapter, and also connecting the temporary terminal block and the old sequence controller input/output module, and controlling the plant by the old sequence controller;
a verification step of connecting the device terminal block and the new sequence controller input/output module to verify the new sequence controller;
The method further includes a stable control step of removing the device terminal block from the new sequence controller input/output module and connecting it to the temporary adapter, thereby controlling the plant using the old sequence controller.
By adopting such a configuration, it is possible to provide a verification step for the new sequence controller described above and a stable control step using the old sequence controller, and by performing the relatively simple switching operation of replacing the equipment terminal block, it is possible to achieve both stable and continuous operation of the plant and reliable verification of the new sequence controller.

In the connection tool of the present disclosure having the above-mentioned configuration, it is preferable that the verification step and the stability control step are executed alternately for each of predefined time periods.
By adopting such a configuration, the verification steps of the new sequence controller can be performed during times when workers are able to perform verification work on the new sequence controller, and the stable control steps using the old sequence controller can be performed during times when workers are unable to perform verification work on the new sequence controller, thereby enabling reliable verification work on the new sequence controller and stable, continuous operation of the plant to be performed with a limited number of workers.

The connection tool of the present disclosure is characterized in that it is a connection tool used in any one of the above-mentioned verification methods.
By adopting such a configuration, the stable control step can be executed using the old sequence controller by connecting the old sequence controller to the equipment terminal block using a connection tool, so that it is possible to easily switch between the above-mentioned verification step of the new sequence controller and the stable control step using the old sequence controller, thereby achieving both stable and continuous operation of the plant and reliable verification of the new sequence controller.

In addition, the connection tool of the present disclosure includes:
In a plant operated by an old or new PLC, a connection tool is provided for connecting an old PLC to a device terminal block connected to a controlled device,
a temporary terminal block for connecting to an old sequence controller input/output module capable of inputting and outputting signals to and from the old sequence controller, a temporary adapter for detachably connecting an equipment terminal block, and a connection cable for electrically connecting the temporary terminal block and the temporary adapter to each other;
The temporary adapter is characterized in having a connection interface that is the same as a connection interface that can connect to the device terminal block in a new sequencer input/output module that can input and output signals to and from the new sequencer.
By adopting such a configuration, it is possible to provide a verification step for the new sequence controller described above and a stable control step using the old sequence controller, and by performing the relatively simple switching operation of replacing the equipment terminal block, it is possible to achieve both stable and continuous operation of the plant and reliable verification of the new sequence controller.

This disclosure provides a verification method and connection tool for replacing an old PLC with a new PLC that can achieve both stable and continuous plant operation and reliable verification of the new PLC.

1 is a diagram showing the configuration of a plant control system used in a verification method for replacing an old programmable controller with a new programmable controller according to an embodiment of the present disclosure. FIG. 1 is a block diagram showing the configuration of a new sequencer used in a plant control system. FIG. 2 is a block diagram showing a configuration of a relay controlled by the plant control system. 1 is a flowchart illustrating a procedure for implementing a verification method for replacing an old sequencer with a new sequencer according to an embodiment of the present disclosure. FIG. 1 is a diagram showing a state in which a plant is controlled by an old sequence controller in a sequence controller panel. This figure shows the state in which the old sequence controller in the sequence controller panel has been moved to a temporary rack and the plant is being controlled by the old sequence controller using a connection tool. FIG. 2 is a diagram illustrating a configuration of a connection tool according to an embodiment of the present disclosure. A diagram showing the new sequencer installed on the sequencer board. This figure shows the state in which the equipment terminal block and the new sequencer input module are connected and the new sequencer is being verified. This figure shows the state in which the equipment terminal block is connected to a temporary adapter and the plant is controlled by the old sequencer. 13 is a flowchart showing a flow for switching between verification of a new sequence controller and control of a plant by an old sequence controller depending on a time period.

The present disclosure will now be described in more detail with reference to the drawings.

Figure 1 shows the configuration of a plant control system 100 used in a verification method for replacing an old sequencer 21 with a new sequencer 31, which is an embodiment of the present disclosure. The plant control system 100 includes a control computer 10 that controls at least one of the old sequencer 21 or the new sequencer 31, a temporary rack 20 on which the old sequencer 21 that can be operated stably is installed, a sequencer panel 30 on which the new sequencer 31 that needs to be verified before being introduced is installed, and a relay panel 40 on which a relay 45 that receives a signal from the old sequencer 21 or the new sequencer 31 and controls the plant is installed.

In the verification method for replacing the old sequencer 21 with the new sequencer 31 according to this embodiment, as shown in Figures 4 to 9, the installation positions of the old sequencer 21 and the new sequencer 31 are changed or newly installed during the implementation process, but the configuration shown in Figure 1 shows the state when step S105 (connecting the device terminal block 43 and the new sequencer I/O module 32 and verifying the new sequencer 31) shown in Figure 3 is being executed.

The control computer 10 communicates with the old sequencer 21 and the new sequencer 31, transmits programs and commands to the old sequencer 21 and the new sequencer 31, and transmits and receives data between the old sequencer 21 and the new sequencer 31. The control computer 10 is connected to the old sequencer 21 and the new sequencer 31 by communication means 15, 17, including wired communication such as USB (Universal Serious Bus) or Ethernet (registered trademark), or wireless communication such as Bluetooth (registered trademark) or WiFi (registered trademark), but is not limited to the communication means exemplified above, and various communication means can be used.

The temporary rack 20 has a housing capable of housing the old sequence controller 21 and the like. The temporary rack 20 is used when verifying the new sequence controller 31, and is provided for installing and operating the old sequence controller 21 when the new sequence controller 31 and the old sequence controller 21 are switched depending on the time period and connected to the relay board 40.

The sequencer board 30 has a housing capable of housing either the new sequencer 31 or the old sequencer 21. In this embodiment, the sequencer board 30 has a housing that has a track record of housing the old sequencer 21 and operating it stably, and can also house the new sequencer 31 that is the subject of verification. In addition to the new sequencer 31 and the old sequencer 21, the sequencer board 30 can be equipped with various sensors, timers, counters, meters, switches, touch panels, etc. on the front. It may also be configured to house other devices such as servo devices and inverters.

The configuration of the new sequencer 31 will now be described. As shown in FIG. 2A, the new sequencer 31 includes a control unit 31a that executes programs stored in the memory unit 31b and performs various controls of the new sequencer 31, a memory unit 31b that stores control programs, received data, and calculation results in the control unit 31a, an input unit 31c that inputs signals from the new sequencer input/output module 32, an output unit 31d that outputs signals to the new sequencer input/output module 32, and a communication unit 31e that communicates with the control computer 10, etc.

Each process in the control unit 31a can be realized as software processing, for example, by having a CPU (Central Processing Unit) or DSP (Digital Signal Processor) included in the control unit 31a execute a specific program stored in the memory unit 31b or the like. However, this is not limited to the above, and each process may be configured to be realized as hardware processing, for example, by an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

The storage unit 31b includes a readable storage medium, which may be a rewritable and programmable ROM such as an EPROM, EEPROM, or flash memory, or other tangible storage medium such as a magnetic disk storage medium capable of storing information, or any combination of these. The storage unit 31b may be provided within the control unit 31a, or may be a storage medium within an external storage device connectable to the new sequencer 31, such as a magnetic cassette, magnetic tape, or other magnetic and optical storage device (e.g., a CD (Compact Disk), a Laser Disk (registered trademark), a DVD (Digital Versatile Disc), a floppy disk (registered trademark), and a Blu-ray Disk (registered trademark)).

The control unit 31a executes a program stored in the storage unit 31b or received from the control computer 10 based on various control parameters received from the control computer 10 via the communication unit 31e. By executing the program, the control unit 31a generates an output signal based on the state of input signals from sensors, switches, etc. from the new sequencer input/output module 32 received via the input unit 31c.

In this embodiment, the output signal output by the control unit 31a is output from the new sequencer input/output module 32 via the output unit 31d, or via the output unit 31d and a drive circuit (not shown). The output signal output from the new sequencer input/output module 32 is input to at least one relay 45 provided in the relay board 40 via the device terminal block 43 and relay connection wiring 46 in FIG. 1.

Figure 2B shows an example of a block diagram showing the internal configuration of relay 45. Relay 45 is equipped with an electromagnet and contact mechanism (not shown), and opens and closes the contacts by using the electromagnetic attraction force generated when a current of a certain value or more is passed through the electromagnet. In the figure, numbers surrounded by circles indicate terminal numbers. In Figure 2B, when a voltage is applied between terminals 1 and 11, the current is converted by resistor 45b and flows through the coil, neon lamp 45a indicating operation is on, and the contacts between terminals 3 and 5, between terminals 2 and 6, and between terminals 7 and 10 are closed. The operation of this relay 45 controls the corresponding controlled device.

In this embodiment, the control unit 31a in the new sequencer 31 executes a program to generate an output signal based on an input signal from the input unit 31c, but this is not limited to the above. For example, the new sequencer 31 may transmit an input signal to an externally located control unit, receive the generated output signal, and output it to the device to be controlled.

In this embodiment, the new sequencer 31 is configured to receive programs, various commands, and parameters from the control computer 10 via the communication unit 31e, but is not limited to this configuration. The new sequencer 31 may also receive this information via the input unit 31c.

The basic configuration of the old sequencer 21 is the same as that shown in Figure 2A, so further explanation will be omitted here.

The relay board 40 in FIG. 1 has a housing capable of housing the relay 45 and the like. As described above, the output signal output from the new sequencer 31 via the new sequencer input/output module 32 is input to the relay 45 provided in the relay board 40 via the device terminal block 43 and the relay connection wiring 46. In this way, by controlling the relay 45 with the new sequencer 31 or the old sequencer 21, it is possible to open and close the contacts connected to other control target devices connected to the relay 45, thereby controlling them. That is, in this embodiment, the relay 45 and other devices connected to the relay 45 are the control target devices.

The connection tool 50 in FIG. 1 includes a temporary terminal block 53 that is electrically and mechanically detachably connected to the connection interface 22a of the old sequencer I/O module 22, a temporary adapter 55 that detachably connects the device terminal block 43 that is connected to the relay 45 that is the device to be controlled, and a connection cable 51 that electrically connects the temporary terminal block 53 and the temporary adapter 55 to each other (see FIG. 6 for details).

As shown in FIG. 1, the connection tool 50 has a temporary terminal block 53 connected to the old sequence controller input/output module 22 of the old sequence controller 21 arranged in the temporary rack 20, while the temporary adapter 55 is arranged in the sequence controller board 30.

Next, a verification method for replacing the old sequencer 21 with the new sequencer 31 according to this embodiment will be described with reference to the flow diagram of FIG. 3 and FIGS. 4 to 9. This verification method is a technique for ensuring that verification of the new sequencer 31 can be performed by a limited number of workers when it is desired to introduce a new sequencer 31 in place of the old sequencer 21 for the purpose of adding new functions or dealing with aging equipment, when the old sequencer 21 is being used to stably and continuously control the controlled equipment.

In the verification method for replacing the old PLC 21 with the new PLC 31 according to this embodiment, first, as shown in FIG. 4, the old PLC 21 is placed in the PLC board 30, and the old PLC 21 controls the plant through control of the control target devices such as the relay 45 (step S101 in FIG. 3). In this step S101, as shown in FIG. 4, the device terminal block 43 is directly and detachably connected to the old PLC input/output module 22 of the old PLC 21, and the connection tool 50 is not used. That is, the connection state shown in FIG. 4 is a state in which the old PLC 21 and the relay 45 (see FIG. 1), which is the control target of the old PLC 21, are electrically connected via the device terminal block 43 and the old PLC input/output module 22. Step S101 (corresponding to FIG. 4) is a state in which the old PLC 21 stably and continuously controls the plant before the new PLC 31 is introduced.

Next, as shown in FIG. 5, the old PLC 21 installed on the PLC board 30 is moved and installed on the temporary rack 20 (step S102 in FIG. 3). Also, as shown in FIG. 5, the device terminal block 43 connected to the relay 45 is connected to the temporary adapter 55 of the connection tool 50, and the temporary terminal block 53 is connected to the old PLC input/output module 22 of the old PLC 21, and the plant is controlled by the old PLC 21 (step S103 in FIG. 3). The device terminal block 43 and the temporary adapter 55 are connected mechanically and electrically via a connection interface 55a provided on the temporary adapter 55 in a detachable manner. The temporary terminal block 53 and the old PLC input/output module 22 are connected mechanically and electrically via a connection interface 22a provided on the old PLC input/output module 22 in a detachable manner. That is, the connection state in FIG. 5 is a state in which the old sequence controller 21 and the relay 45 (see FIG. 1) that is the control target of the old sequence controller 21 are electrically connected via the temporary terminal block 53, the connection cable 51, the temporary adapter 55, and the equipment terminal block 43. This step S103 makes it possible to confirm that the plant can be controlled by the old sequence controller 21 in the same way as before (as in step S101 and FIG. 4) even in a state in which the temporary rack 20 and the connection tool 50 are used.

In FIG. 5, the connection tool 50 includes a temporary terminal block 53 that is detachably connected to the connection interface 22a of the old sequencer I/O module 22, a temporary adapter 55 that detachably connects the device terminal block 43 that is connected to the relay 45, which is the device to be controlled, and a connection cable 51 that interconnects the temporary terminal block 53 and the temporary adapter 55 (see FIG. 6).

As shown in FIG. 6, the temporary terminal block 53 has multiple terminals exposed on its top surface (the surface vertical to the surface of FIG. 6), and one end of each of the multiple cables of the connection cable 51 is electrically connected to each of the multiple terminals in a one-to-one relationship. The temporary terminal block 53 is electrically and mechanically detachably connected to the connection interface 22a of the old sequencer input/output module 22 at its bottom (the part vertical to the surface of FIG. 6). In this embodiment, the device terminal block 43 connected to the relay 45, which is the device to be controlled, also has a configuration similar to that of the temporary terminal block 53.

As shown in FIG. 6, the temporary adapter 55 is connected to the end of the connection cable 51 of the connection tool 50 opposite the temporary terminal block 53, and in this embodiment is electrically connected to the connection cable 51 via a plurality of connectors 56. As shown in FIG. 5, the temporary terminal block 53 of the connection tool 50 is connected to the old sequencer input/output module 22 of the old sequencer 21 arranged in the temporary rack 20, while the temporary adapter 55 is arranged in the sequencer board 30. Then, as shown in FIG. 5, by connecting the device terminal block 43 to the connection interface 55a of the temporary adapter 55, the old sequencer 21 can control the relay 45, which is a controlled device.

Next, as shown in FIG. 7, the new sequencer 31 is installed in the storage section 30s (see FIG. 5) in which the old sequencer 21 was installed in step S101 on the sequencer board 30 (step S104 in FIG. 3). In this embodiment, the new sequencer 31 is housed in a housing that is large enough to fit in the storage section 30s, just like the old sequencer 21, so it can be fixed in the storage section 30s via a mounting member dedicated to the new sequencer 31. The housing of the new sequencer 31 may be made common to the housing of the old sequencer 21 to further facilitate installation of the new sequencer 31.

Next, as shown in FIG. 8, the device terminal block 43 connected to the relay 45, which is the device to be controlled, is removed from the connection interface 55a of the temporary adapter 55 and connected to the new sequencer input/output module 32 of the new sequencer 31, and the new sequencer 31 is verified (step S105 in FIG. 3). By connecting the device terminal block 43 to the new sequencer input/output module 32 via the connection interface 32a, the new sequencer 31 can control the relay 45, which is the device to be controlled, without going through the connection tool 50. In other words, the connection state in FIG. 8 is a state in which the new sequencer 31 and the relay 45, which is the control target of the new sequencer 31 (the same relay 45 as the control target of the old sequencer 21), are electrically connected via the device terminal block 43 and the new sequencer input/output module 32.

In this embodiment, the temporary adapter 55 is configured to have the same connection interface 55a as the connection interface 32a that can connect to the device terminal block 43 in the new sequencer input/output module 32 that can input and output signals to the new sequencer 31. Therefore, as shown in FIG. 8, the device terminal block 43 can be easily replaced from the connection interface 55a of the temporary adapter 55 to the connection interface 32a of the new sequencer input/output module 32 to start verification of the new sequencer 31.

When the verification of the new PLC 31 is interrupted, as shown in FIG. 9, the device terminal block 43 is removed from the new PLC input/output module 32 and connected to the connection interface 55a of the temporary adapter 55, and the plant is controlled by the old PLC 21 (step S106 in FIG. 3). By reattaching the device terminal block 43 to the temporary adapter 55 as described above, the device terminal block 43 and the old PLC 21 can be connected via the connection tool 50 as in FIG. 5, so that the verification of the new PLC 31 can be interrupted midway and the plant can be quickly switched to control by the old PLC 21.

It is desirable to complete the verification of the new PLC 31 without interruption midway, but as PLC functions improve and plants become more complex, the verification work of the newly introduced new PLC 31 becomes more complicated and the verification time tends to increase. Therefore, for example, as shown in FIG. 10, one possible method is to verify the new PLC 31 during daytime hours when workers are available to work, and suspend the verification of the new PLC 31 during nighttime hours when workers are unable to work, and continue control of the plant using the old PLC 21.

In FIG. 10, after starting the verification of the new sequence controller 31, during the daytime hours when the worker can perform the verification work (YES in step S201 in FIG. 10), as shown in FIG. 8, the device terminal block 43 is connected to the new sequence controller I/O module 32 of the new sequence controller 31, and the new sequence controller 31 is verified (step S205 in FIG. 10). This step S205 corresponds to step S105 in FIG. 3.

In this way, during the daytime, step S201 is YES, and verification of the new PLC 31 continues. Then, when verification of the new PLC 31 is completed (step S207 in FIG. 10 is YES), the connection state in FIG. 8 is maintained, and the operation of controlling the plant by the new PLC 31 continues. In this case, the temporary rack 20, old PLC 21, and connection tool 50 in FIG. 8 may be removed.

On the other hand, if verification of the new PLC 31 has not been completed in step S207 of FIG. 10 (NO in step S207 of FIG. 10) and it is not the verification time period in step S201, i.e., it is the middle of the night (NO in step S201 of FIG. 10), the connection state is switched to that of FIG. 9, and the plant is controlled by the old PLC 21 (step S206 of FIG. 10). This step S206 corresponds to step S106 in FIG. 3.

When the midnight period that is not a verification period ends (YES in step S201 in FIG. 10), the connection state is switched back to that of FIG. 8, and verification of the new sequencer 31 is resumed (step S205 in FIG. 10). Steps S205 and S206 are repeated until verification of the new sequencer 31 is completed (until YES is returned in step S207 in FIG. 10).

As described above, this embodiment is a verification method for replacing an old sequence controller 21 with a new sequence controller 31 in a plant control system 100 that operates a plant using a sequence controller. The plant control system 100 includes an old sequence controller 21 that connects to a controlled device (relay 45) via an old sequence controller input/output module 22, a new sequence controller 31 that connects to a controlled device via a new sequence controller input/output module 32, a temporary rack 20 that houses the old sequence controller 21, and a new sequence controller 31 that connects to a controlled device via a new sequence controller input/output module 32. The connection tool 50 has a temporary terminal block 53 that is detachably connected to the old sequencer input/output module 22, a temporary adapter 55 that detachably connects to a device terminal block 43 that is connected to the device to be controlled, and a connection cable 51 that electrically connects the temporary terminal block 53 and the temporary adapter 55 to each other, and the device terminal block 43 is connected to the old sequencer input/output module 22, the temporary The new PLC can be detachably connected to either the adapter 55 or the new PLC input/output module 32, and the verification method is configured to include an initial operation confirmation step of connecting the equipment terminal block 43 to the old PLC input/output module 22 and controlling the plant using the old PLC 21 in the PLC board 30, a relocation step of moving the old PLC 21 installed in the PLC board 30 to the temporary rack 20 and installing it there, a post-relocation operation confirmation step of connecting the equipment terminal block 43 to the temporary adapter 55 and connecting the temporary terminal block 53 to the old PLC input/output module 22 and controlling the plant using the old PLC 21, an installation step of installing the new PLC 31 on the PLC board 30, a verification step of connecting the equipment terminal block 43 to the new PLC input/output module 32 and verifying the new PLC 31, and a stable control step of removing the equipment terminal block 43 from the new PLC input/output module 32 and connecting it to the temporary adapter 55, and controlling the plant using the old PLC 21. By adopting this configuration, a verification step for the new sequence controller 31 and a stable control step using the old sequence controller 21 are provided, and by performing the relatively simple switching operation of replacing the device terminal block 43, it is possible to achieve both stable and continuous operation of the plant and reliable verification of the new sequence controller.

In addition, in this embodiment, the verification step and the stable control step are configured to be executed alternately for each predefined time period. By adopting such a configuration, the verification step of the new sequence controller 31 can be executed during the time period when the workers can perform the verification work of the new sequence controller 31, and the stable control step using the old sequence controller 21 can be executed during the time period when the workers cannot perform the verification work of the new sequence controller 31. This makes it possible to perform reliable verification work of the new sequence controller 31 and stable and continuous operation of the plant with a limited number of workers.

In addition, in this embodiment, a connection tool 50 is configured for use in any of the above-mentioned verification methods. By adopting such a configuration, a stable control step can be executed by the old sequencer 21 by connecting the old sequencer 21 to the device terminal block 43 with the connection tool 50, so that it is possible to easily switch between the verification step of the new sequencer 31 described above and the stable control step by the old sequencer 21, thereby achieving both stable and continuous operation of the plant and reliable verification of the new sequencer.

In addition, in this embodiment, in a plant operated by an old sequence controller 21 or a new sequence controller 31, a connection tool 50 that connects the old sequence controller 21 to a device terminal block 43 connected to a controlled device includes a temporary terminal block 53 that connects to an old sequence controller input/output module 22 capable of inputting and outputting signals to the old sequence controller 21, a temporary adapter 55 that detachably connects the device terminal block 43, and a connection cable 51 that electrically connects the temporary terminal block 53 and the temporary adapter 55 to each other, and the temporary adapter 55 is configured to have the same connection interface 55a as the connection interface 32a that can connect the device terminal block 43 in the new sequence controller input/output module 32 that can input and output signals to the new sequence controller 31. By adopting such a configuration, the above-mentioned verification step of the new sequence controller 31 and the stable control step by the old sequence controller 21 are provided, and by the relatively easy switching operation of replacing the device terminal block 43, it is possible to achieve both stable and continuous operation of the plant and reliable verification of the new sequence controller.

Although the present disclosure has been described based on various drawings and examples, it should be noted that a person skilled in the art would be able to easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present invention. For example, the functions contained in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined into one or divided. It should be understood that these are also included in the scope of the present invention.

For example, in this embodiment, the new sequencer 31 or the old sequencer 21 is configured to control other controlled devices via the relay 45, which is a controlled device, but this is not limited to this aspect. The new sequencer 31 or the old sequencer 21 may be configured to directly control controlled devices other than the relay 45 without going through the relay 45.

In addition, in this embodiment, the new sequence controller 31 is verified during daytime hours when workers are available to work, and the old sequence controller 21 controls the plant during the night, but this is not limited to the above. It is possible to switch between verifying the new sequence controller 31 and controlling the plant with the old sequence controller 21 at any time. For example, the new sequence controller 31 can be verified during a first time period during the day, and the old sequence controller 21 controls the plant during a second time period during the day, allowing for flexible switching in accordance with the working hours of workers, etc.

This disclosure makes it possible to propose a verification method for replacing an old sequence controller 21 with a new sequence controller 31, which can achieve both stable and continuous operation of the plant and reliable verification of the new sequence controller.

10 Control computer 15, 17 Communication means 20 Temporary rack 21 Old sequencer 22 Old sequencer input/output module 22a Connection interface 30 Sequencer board 30s Storage section 31 New sequencer 31a Control section 31b Memory section 31c Input section 31d Output section 31e Communication section 32 New sequencer input/output module 32a Connection interface 40 Relay board 43 Device terminal block 45 Relay 45a Neon lamp 45b Resistor 46 Relay connection wiring 50 Connection tool 51 Connection cable 53 Temporary terminal block 55 Temporary adapter 55a Connection interface 56 Connector 100 Plant control system

Claims (4)

A verification method for replacing an old sequence controller with a new sequence controller in a plant control system that operates a plant using a sequence controller, comprising:
The plant control system includes:
An old sequence controller that connects to the controlled device via the old sequence controller I/O module,
A new PLC that connects to the controlled equipment via a new PLC I/O module,
A temporary rack for accommodating the old sequencer;
a sequencer board housing either the old sequencer or the new sequencer;
a connection tool for connecting the old sequence controller to a control target device,
the connection tool includes a temporary terminal block that is detachably connected to the old sequence controller input/output module, a temporary adapter that detachably connects an equipment terminal block that is connected to a controlled equipment, and a connection cable that electrically connects the temporary terminal block and the temporary adapter to each other;
the device terminal block is detachably connectable to any one of the old sequence controller input/output module, the temporary adapter, or the new sequence controller input/output module;
The verification method includes:
an initial operation confirmation step of connecting the device terminal block to the old sequencer input/output module and controlling the plant by the old sequencer in the sequencer board;
a relocation step of moving and installing the old sequence controller installed on the sequence controller board on the temporary rack;
a post-relocation operation confirmation step of connecting the device terminal block and the temporary adapter, and also connecting the temporary terminal block and the old sequence controller input/output module, and controlling the plant by the old sequence controller;
a verification step of connecting the device terminal block and the new sequence controller input/output module to verify the new sequence controller;
A verification method characterized by including a stable control step of removing the equipment terminal block from the new sequence controller input/output module and connecting it to the temporary adapter, and controlling the plant using the old sequence controller. The verification method according to claim 1, wherein the verification step and the stability control step are performed alternately for each predefined time period. A connection tool for use in the verification method according to claim 1 or 2. In a plant operated by an old or new PLC, a connection tool is provided for connecting an old PLC to a device terminal block connected to a controlled device,
a temporary terminal block for connecting to an old sequence controller input/output module capable of inputting and outputting signals to and from the old sequence controller, a temporary adapter for detachably connecting an equipment terminal block, and a connection cable for electrically connecting the temporary terminal block and the temporary adapter to each other;
A connection tool characterized in that the temporary adapter has a connection interface that is the same as a connection interface that can connect to the device terminal block in a new sequencer input/output module that can input and output signals to and from the new sequencer.

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