JP2014016947A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a programmable controller capable of easily rewriting a program in a short time.SOLUTION: There is provided a programmable controller including a first storage part 17 which stores a sequence program defining the operation of a controlled system, an arithmetic processing part 10 which executes the sequence program so as to control the operation of the controlled system, and an interface 30 which can make a communication connection with the outside. The arithmetic processing part is set in one of a normal mode in which the operation of the controlled system is controlled using the sequence program, a rewrite mode in which the sequence program stored in the first storage part is permitted to be rewritten, and an output mode in which the sequence program stored in the first storage part is output from the interface so as to rewrite a sequence program of another programmable controller.

Description

  Embodiments according to the present invention relate to a programmable controller, for example, a programmable controller that stores a program for sequence control.

  A programmable controller (hereinafter also referred to as a PLC (Programmable Logic Controller)) automatically performs sequence control on a control target connected to the PLC by executing an application program (sequence program) created by a user.

  A sequence program executed by the PLC is usually created using a programming device, converted into machine code, and then transferred to the PLC. The PLC operates with the system program as a base layer program, and executes the sequence program transferred from the programming device. As a result, the PLC can perform automatic sequence control of the controlled object.

  Such a PLC sequence program may be rewritten as necessary. In the case of rewriting the sequence program, the PLC sequence program has been conventionally rewritten using a rewriting tool such as a personal computer.

Japanese Patent Laid-Open No. 2005-100028 JP-A-6-95719

  However, when rewriting a sequence program of a plurality of PLCs, the user needs to rewrite the sequence program repeatedly by connecting a rewriting tool to each PLC.

  It is also conceivable to simultaneously rewrite a plurality of PLC programs via a network. However, in this case, the PLCs to be rewritten must be connected to each other via a network, and at the time of rewriting, the rewriting tool must be connected in parallel to all the PLCs. For an independent PLC that is not connected to the network, the user needs to connect to the network at the time of rewriting the program, or to rewrite the program by connecting a rewriting tool to each independent PLC. Therefore, conventionally, rewriting the sequence program has taken time and effort.

  Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a programmable controller that can rewrite a program easily and in a short time.

  The programmable controller according to the present embodiment includes a first storage unit that stores a sequence program that defines an operation to be controlled, an arithmetic processing unit that executes the sequence program to control the operation to be controlled, and an external communication connection A programmable controller having a possible interface, wherein the arithmetic processing unit rewrites the normal mode for controlling the operation of the control target using the sequence program, and rewrites the sequence program stored in the first storage unit In order to rewrite the mode or the sequence program of another programmable controller, the sequence program stored in the first storage unit is set to either the output mode for outputting from the interface.

  The programmable controller may further include a switch that sets the mode of the arithmetic processing unit to any one of a normal mode, a rewrite mode, and an output mode.

  The programmable controller and other programmable controllers may have the same configuration.

  In the output mode, the interface is communicably connected to another programmable controller set to the rewrite mode, and the arithmetic processing unit outputs the sequence program in the first storage unit to the other programmable controller via the interface. Also good.

  In the output mode, the interface may be communicably connected to a plurality of other programmable controllers, and the arithmetic processing unit may output the sequence program in the first storage unit to the plurality of other programmable controllers via the interface. .

  In the output mode, the interface is communicably connected to another programmable controller set to the rewrite mode, and the arithmetic processing unit transfers the sequence program of the first storage unit to the storage unit of the other programmable controller via the interface. You may write.

  The programmable controller further includes a second storage unit that is faster in writing speed than the first storage unit, and in the rewrite mode, the arithmetic processing unit temporarily stores the sequence program received from the outside in the second storage unit. Thereafter, the sequence program may be written from the second storage unit to the first storage unit.

  The interface may be communicably connected to another programmable controller by serial communication, parallel communication, or network communication.

The figure which shows the structural example of PLC by 1st Embodiment. The figure which shows the connection relation of PLC100 and PLC200 at the time of rewriting of a sequence program. The flowchart which shows operation | movement of PLC100,200. The flowchart which shows operation | movement of PLC100,200.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration example of a PLC according to the first embodiment. The PLC 100 includes a CPU (Central Processing Unit) module 10, a communication module 20, interfaces 30 and 50, and an I / O module 40. The I / O module 40 is communicably connected to the control target, and the CPU module 10 performs sequence control of the control target (not shown) via the I / O module 40.

  The CPU module 10 includes constituent elements 11 to 18 connected to each other via an internal system bus 19. The CPU 11 executes a system program stored in the system memory 15 and controls the operation of each component in the CPU module 10. At the same time, the CPU 11 executes the sequence program stored in the sequence memory 17 as the first storage unit to perform the sequence control of the control target.

  The system memory 15 stores a system program. The system program functions as an OS (Operating System) for executing a user application program such as a sequence program. The system memory 15 is configured using a flash memory, for example.

  The sequence memory 17 as a first storage unit stores a user sequence program received from the interface 30. The sequence program is a user application executed on the system program and defines the operation to be controlled. Usually, the sequence program is created by the user to arbitrarily operate the control target, and is stored in the sequence memory 17 via the interface 30. When changing the operation to be controlled, the user may rewrite the sequence program in the sequence memory 17. The sequence memory 17 is configured using, for example, a flash memory.

  The work memory 16 as the second storage unit is a memory that temporarily stores data related to control processing executed by the CPU 11 based on the system program and the sequence program. The work memory 16 is configured using, for example, an SRAM.

  The driver / receiver 13 transmits / receives a sequence program and the like from the outside via the interface 30.

  The bus interface 14 is connected between the I / O module 40 and the system bus 19, and inputs or outputs information related to control in order to perform sequence control on the control target.

  The mode switch 18 is a switch for switching the operation mode of the CPU module 10. The operation mode of the CPU module 10 includes, for example, a normal mode, a rewrite mode, and an output mode. The normal mode is a mode in which a control target is sequence controlled using a sequence program. The rewrite mode is a mode that permits rewriting of the sequence program stored in the sequence memory 17. The output mode is a mode in which the sequence program stored in the sequence memory 17 is output from the interface 30 in order to rewrite the sequence program of another programmable controller.

  The mode switch 18 can set the CPU module 10 to any one of a normal mode, a rewrite mode, and an output mode. The mode switch 18 is configured using, for example, a dip switch. In this case, the mode can be switched by the user operating the dip switch ON / OFF.

  In the rewrite mode, the PLC 100 outputs an output request signal or a mode signal indicating the rewrite mode. Thereby, other PLCs or rewriting tools connected to the PLC 100 can know that the PLC 100 is in the rewriting mode and the sequence program in the sequence memory 17 can be rewritten.

  In the output mode, the PLC 100 outputs a rewrite request signal or a mode signal indicating the output mode. Thereby, the other PLCs connected to the PLC 100 can know that the PLC 100 is in the output mode and is in a state where the sequence program in the sequence memory 17 can be output.

  The communication module 20 can be connected to a network (for example, the Internet, LAN, etc.) via the interface 50.

  FIG. 2 is a diagram showing a connection relationship between the PLC 100 and the PLC 200 when the sequence program is rewritten. The PLC 200 has the same configuration as the PLC 100. However, in order to distinguish each component of PLC100 and PLC200, in FIG. 2, "a" is added to the reference number of the component of PLC100, and "b" is added to the reference number of the component of PLC200. doing.

  The interface 30a of the PLC 100 and the interface 30b of the PLC 200 are communicably connected via a communication line 300. The communication line 300 may be any of serial communication, parallel communication, or network communication. The communication line 300 may be either wired or wireless, for example, any of a telephone line, the Internet, a LAN, and the like.

  For example, it is assumed that the PLC 100 is set to the rewrite mode and the PLC 200 is set to the output mode. In this case, the PLC 200 outputs the sequence program stored in the sequence memory 17b from the interface 30b in order to rewrite the sequence program of the PLC 100.

  Since the PLC 100 is set to the rewrite mode, when receiving a new sequence program from the PLC 200, the CPU 11a rewrites the sequence program in the sequence memory 17a with the new sequence program.

  Conversely, when the PLC 200 is set to the rewrite mode and the PLC 100 is set to the output mode, the PLC 100 interfaces the sequence program stored in the sequence memory 17a in order to rewrite the sequence program of the programmable controller of the PLC 200. Output from 30a.

  Since the PLC 200 is set to the rewrite mode, when receiving a new sequence program from the PLC 100, the CPU 11b rewrites the sequence program in the sequence memory 17b with the new sequence program.

  Thus, the PLCs 100 and 200 according to the present embodiment have a rewrite mode and an output mode in addition to the normal mode. Thus, although the PLCs 100 and 200 have the same configuration, one of them can rewrite the other sequence program.

  Of course, in order to rewrite the sequence program between the PLC 100 and the PLC 200, it is first necessary for either the PLC 100 or 200 to store a new sequence program. First, a rewriting tool 400 such as a personal computer is used to write a new sequence program to either the PLC 100 or 200.

  3 and 4 are flowcharts showing the operation of the PLCs 100 and 200. FIG. The operation of the PLCs 100 and 200 will be described in more detail with reference to FIGS. FIG. 3 shows the operation of the PLCs 100 and 200 in the rewrite mode. FIG. 4 shows the operation of the PLCs 100 and 200 in the output mode.

[Normal mode]
In the normal mode, the PLC 100 performs sequence control on the control target via the control bus interface 14a and the I / O module 40a based on the sequence program in the sequence memory 17a. That is, the PLC 100 performs a normal operation (S2).

[Rewrite mode (Fig. 3)]
When the user switches the mode switch 18a to the rewrite mode in order to rewrite the sequence program of the PLC 100, the PLC 100 enters the rewrite mode (S3). In the rewrite mode, the CPU 11a allows the sequence program in the sequence memory 17a to be rewritten. In addition, the PLC 100 waits for an external sequence program rewrite request signal.

  Next, the other PLC 200 or the rewriting tool 400 set in the output mode is connected to the interface 30a (see FIG. 2) (S20).

  When the PLC 200 or the rewrite tool 400 outputs a rewrite request signal or an output mode signal for the sequence program (S30), the PLC 100 receives the rewrite request signal or the output mode signal via the interface 30a and the driver / receiver 13a. The PLC 100 returns the output request signal or the rewrite mode signal in response to the rewrite request signal or the output mode signal (S40). Note that the rewrite request signal or output mode signal and the output request signal or rewrite mode signal include identifiers (for example, addresses) of the transmission source and the transmission destination.

  When the PLC 200 or the rewriting tool 400 receives the output request signal or the rewriting mode signal, the PLC 200 or the rewriting tool 400 transmits a new sequence program stored in its own memory (for example, the sequence memory 17b) one by one (S50).

  Note that either the timing at which the PLC 200 or the rewrite tool 400 outputs the rewrite request signal or the output mode signal and the timing at which the PLC 100 outputs the output request signal or the rewrite mode signal may be first. That is, it is only necessary to know that the PLC 100 and the PLC 200 (or the rewriting tool 400) are set to the rewriting mode and the output mode, respectively, and that they are ready to output and rewrite the sequence program.

  When the PLC 100 receives the new sequence program, the CPU 11a stores the new sequence program in the sequence memory 17a, and rewrites the existing sequence program in the sequence memory 17a with the new sequence program (S60). At this time, the PLC 100 may temporarily store the received new sequence program in the work memory 16a as the second storage unit, and then store the new sequence program from the work memory 16a to the sequence memory 17a.

  Thereafter, the PLC 100, the PLC 200, or the rewriting tool 400 performs verification of the new sequence program stored in the PLC 100 (S70). After confirming that the sequence program has been rewritten normally, the communication between the PLC 100 and the PLC 200 or the rewriting tool 400 ends.

  Furthermore, when the user returns the mode switches 18a and 18b to the normal mode, the PLCs 100 and 200 return to the normal mode, respectively.

[Output mode (Fig. 4)]
In order to output the PLC 100 sequence program to another PLC 200, the user switches the mode switch 18a of the PLC 100 to the output mode (S11).

  Next, another PLC 200 set in the rewrite mode is connected to the interface 30a of the PLC 100 (S21).

  When the PLC 100 outputs a sequence program rewrite request signal or output mode signal (S31), the PLC 200 receives the rewrite request signal or output mode signal via the interface 30b and the driver / receiver 13b. The PLC 200 returns an output request signal or a rewrite mode signal in response to the rewrite request signal or the output mode signal (S41).

  When the PLC 100 receives the output request signal or the rewrite mode signal, the CPU module 10a of the PLC 100 transmits a new sequence program stored in its own sequence memory 17a one by one (S51).

  When the PLC 200 receives the new sequence program, the CPU 11b rewrites the existing sequence program in the sequence memory 17b with the new sequence program (S61).

  Thereafter, the PLC 100 or PLC 200 verifies the new sequence program stored in the PLC 200 (S71). After confirming that the sequence program has been rewritten normally, the communication between the PLC 100 and the PLC 200 ends.

  Furthermore, when the user returns the mode switches 18a and 18b to the normal mode, the PLCs 100 and 200 return to the normal mode, respectively.

  When the PLCs 100 and 200 are connected in steps S20 and S21, and one of them is in the normal mode, the rewrite request signal (or output mode signal) and output request signal (or rewrite) required when rewriting the sequence program. Mode signal) is not output. Therefore, the PLCs 100 and 200 do not erroneously output the sequence program or rewrite the sequence program.

  According to the present embodiment, in rewriting the sequence program of the PLCs 100 and 200, the rewriting tool 400 is performed only once. Thereafter, the rewriting of the sequence program is executed by exchanging the sequence program between the PLCs 100 and 200. Therefore, according to the present embodiment, the rewriting tool 400 is used as little as possible, and it is not necessary to connect the rewriting tool 400 to each of the plurality of PLCs 100 and 200. The number of rewriting tools 400 may be as small as possible.

  Further, the rewriting tool 400 does not need to be connected to the plurality of PLCs 100 and 200 in parallel. For example, when the PLC 100 and the PLC 200 are connected to each other via a network such as a LAN, the rewriting tool 400 may write a new sequence program into one of the PLCs 100 or 200 via the Internet or the like. Thereafter, PLCs connected to the LAN can rewrite the sequence program with each other. Thereby, the use time of the rewriting tool 400 can be shortened, and the rewriting time of the sequence program can be shortened. As a result, the PLC according to the present embodiment can rewrite the sequence program easily and in a short time.

  Further, as described above, in the rewrite mode, the PLC 100 temporarily stores the received new sequence program in the work memory 16a as the second storage unit, and then stores the new sequence program from the work memory 16a to the sequence memory 17a. May be. The work memory 16a is, for example, an SRAM, and has a higher writing speed than the sequence memory 17a configured by a flash memory. Therefore, once the sequence program is stored in the work memory 16a, the communication time between the PLC 100 and the PLC 200 (or the rewriting tool) is shortened. That is, the time for writing the sequence program to the PLC 100 is apparently shortened.

  In the above embodiment, the PLC 100 is connected to one PLC 200. However, the PLC 100 may be connected to a plurality of PLCs 200. By setting the PLC 100 to the output mode and all the plurality of PLCs 200 to the rewrite mode, the CPU 11a of one PLC 100 can output the sequence program in the sequence memory 17a to the other PLCs 200. . Thereby, one PLC100 can rewrite the sequence program of several PLC200 simultaneously.

  The mode switch 18b of the PLC 200 that does not require rewriting of the sequence program among the plurality of PLCs 200 connected to the PLC 100 may be set to the normal mode. As described above, when the PLC 100 is in the normal mode when the PLC 100 is connected, the PLC 200 does not output an output request signal or a rewrite mode signal. Since the PLC 200 that needs to be rewritten is in the rewrite mode, it outputs an output request signal or a rewrite mode signal. At this time, the output request signal or the rewrite mode signal includes the identifier of the PLC 200 that is the transmission source and the identifier of the PLC 100 that is the transmission destination. Therefore, the PLC 100 can accurately output the sequence program to the PLC 200 that needs to be rewritten in response to the output request signal or the rewrite mode signal. At this time, the PLC 200 sequence program that does not require rewriting is not rewritten.

(Second Embodiment)
In the first embodiment, when the PLC 100 set in the rewrite mode receives a new sequence program, the CPU 11a temporarily stores the new sequence program in the work memory 16a, and then stores the sequence program from the work memory 16a to the sequence memory 17a. I am writing.

  In the second embodiment, the PLC 200 set to the output mode directly writes the sequence program to the sequence memory 17a of the PLC 100 via the interface 30a. In this case, since the CPU 11b of the PLC 200 writes the sequence program to the sequence memory 17a of the PLC 100, the load applied to the CPU 1a of the PLC 100 set in the rewrite mode is reduced.

  Of course, when the PLC 100 is in the output mode and the PLC 200 is in the rewrite mode, the CPU 11a of the PLC 100 directly writes the sequence program into the sequence memory 17b of the PLC 200.

  Thus, according to the second embodiment, the PLC CPU on the output mode side may rewrite the PLC sequence program on the rewrite mode side in consideration of the load on the PLC CPU.

(Third embodiment)
In the third embodiment, the mode switch 18 is a software switch. That is, the mode switch 18 may be a program incorporated in a system program such as BIOS (Basic Input / Output System).

  In this case, for example, when nothing is connected to the interface 30a of the PLC 100, the PLC 100 operates as being in the normal mode.

  When the PLC 200 is connected to the interface 30a of the PLC 100, the PLC 100 detects the connection and transmits the version information of the sequence program stored in the sequence memory 17a to the PLC 200. At this time, the PLC 200 also detects the connection of the PLC 100 and transmits the version information of the sequence program stored in the sequence memory 17b to the PLC 100. The CPUs 11a and 11b of the PLC 100 and the PLC 200 compare the version information of each sequence program. The sequence program is configured to execute such an operation. Then, the PLC having the old sequence program becomes the rewrite mode, and the PLC having the new sequence program becomes the output mode. For example, when the sequence program stored in the PLC 100 is an older version than the sequence program stored in the PLC 200, the PLC 100 enters the rewrite mode and the PLC 200 enters the output mode. Then, the PLC 200 outputs its own sequence program, and the PLC 100 rewrites the sequence program in the sequence memory 17a with the sequence program received from the PLC 200.

  After each mode of the PLCs 100 and 200 is determined, the PLCs 100 and 200 may execute the steps after step S30 shown in FIG. 3 or the steps after step S31 shown in FIG. As a result, the PLC 100 sequence program is rewritten to a new version of the sequence program.

  According to the third embodiment, the PLC automatically compares the versions of the sequence programs with each other when connected to another PLC. Therefore, when rewriting the sequence program, the user only needs to connect the PLC to another PLC, and does not need to switch the mode switches 18a and 18b. That is, the user does not need to be aware of the PLC mode. Furthermore, the third embodiment can also obtain the effects of the first embodiment.

100 ... PLC, 10 ... CPU module, 20 ... communication module, 30 ... interface, 40 ... I / O module, 11 ... CPU, 13 ... driver / receiver, 14 ... Bus interface, 15 ... System memory, 16 ... Work memory, 17 ... Sequence memory, 18 ... Mode switch

Claims (8)

A first storage unit that stores a sequence program that defines an operation to be controlled;
An arithmetic processing unit that executes the sequence program to control the operation of the control target;
A programmable controller having an interface capable of communication connection with the outside,
The arithmetic processing unit may be a normal mode for controlling the operation of the control target using the sequence program, a rewrite mode for permitting rewriting of the sequence program stored in the first storage unit, or another programmable controller. In order to rewrite the sequence program, the programmable controller is set to one of output modes in which the sequence program stored in the first storage unit is output from the interface.   The programmable controller according to claim 1, further comprising a switch that sets a mode of the arithmetic processing unit to any one of the normal mode, the rewrite mode, and the output mode.   The programmable controller according to claim 1, wherein the programmable controller and the other programmable controller have the same configuration. In the output mode,
The interface is communicably connected to another programmable controller set to the rewrite mode,
The said arithmetic processing part outputs the said sequence program of the said 1st memory | storage part to said other programmable controller via the said interface, The Claim 1 characterized by the above-mentioned. Programmable controller. In the output mode,
The interface is communicatively connected to a plurality of other programmable controllers,
The said arithmetic processing part outputs the said sequence program of the said 1st memory | storage part to several said other programmable controller via the said interface, The Claim 1 characterized by the above-mentioned. The programmable controller described. In the output mode,
The interface is communicably connected to another programmable controller set to the rewrite mode,
The said arithmetic processing part writes the said sequence program of the said 1st memory | storage part to the memory | storage part of said other programmable controller via the said interface, The Claim 1 characterized by the above-mentioned. The programmable controller described. A second storage unit having a writing speed faster than that of the first storage unit;
In the rewrite mode,
The arithmetic processing unit temporarily stores a sequence program received from the outside in the second storage unit, and then writes the sequence program from the second storage unit to the first storage unit. The programmable controller as described in any one of Claims 1-6.   8. The programmable controller according to claim 1, wherein the interface is communicably connected to the other programmable controller by serial communication, parallel communication, or network communication. .

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