JP6538510B2 - Programmable controller - Google Patents

Description

  The present invention relates to a programmable controller (also called a programmable logic controller) used to control various machines.

  FIG. 2 shows a block diagram of a general programmable logic controller (hereinafter referred to as PLC) called a building block type. In the following, unless otherwise noted, PLC in this document refers to the building block type.

  Connectors are attached to the base unit (basic) 1, base unit (extension) 10, power supply module 2, CPU module 3, I / O module 4, expansion control module 5 etc. so that each module can be attached to the base unit It has become. The base unit (basic) 1 and the base unit (extension) 10 are connected by the extension connection cable 6 via the extension control module 5. The user implements I / O modules having functions to realize a desired control system, and implements a control system by programming a program for controlling those I / O modules to the CPU module 3. .

  Power is supplied from the power supply module 2 to the CPU module 3 and the I / O module 4 through the base unit (basic) 1 and the base unit (extension) 10. In the CPU module 3, a program programmed by the user using the PLC is arithmetically processed. The program in the CPU module 3 receives an input signal from the I / O module 4 and performs arithmetic processing, or, conversely, outputs the result of arithmetic processing in the CPU module 3 from the I / O module 4 Perform the desired control action.

  For example, in Patent Document 1, “a programmable controller board module that executes a special function in a programmable controller configured by connecting a plurality of input / output units to a central processing unit that executes a predetermined program via a base unit is disclosed. A programmable controller characterized in that the programmable controller board module is attachable to the central processing unit.

JP-A-6-324722

  As described above, the building block type PLC is suitable for freely combining units of equipment called modules having various functions to construct a control system required by the user.

  Not only PLCs, but also general products have the concept of a series, and it is rare for the product series to be delivered to the market for an indefinite period of time. In particular, in products such as PLCs that are composed of electronic components such as ICs, the product lineup tends to be renewed in several years because the speed of technological innovation in electronic components is fast. Also, in general, product specifications between the new and old series are often different, for example, there are many cases in which the size of the product is several-fold for the purpose of improving processing speed or reducing the installation area of the product. .

  On the other hand, I think that I will be in the position of using PLC. If the user is building a control system with the "Series X" PLC product group, and if the PLC product group has to be renewed for some reason, the "Series X" has already been discontinued and its successor It is possible that "series Y" is supplied to the market as a product. While there are many cases where functional compatibility such as ladder program is maintained between both "Series X" and "Series Y" series, internal processings that differ in product dimensions and realize the arithmetic function of PLC The speed has been greatly speeded up. Therefore, there is a problem that the module of "series Y" can not be used as it is to the PLC system built by "series X". This problem imposes a large cost burden on the user due to the renewal to the new series, and sometimes the production facilities can not be used for a long time during the renewal work period. Therefore, there is a possibility that the user may lose the opportunity.

  Patent Document 1 does not consider combining and using different modules in a series.

  The present invention has been made in view of the above, and an object thereof is to make it possible to use an old series module in combination with a new series product as it is in different series programmable controllers.

  In the present invention, in order to solve this problem, the base unit of the new series has the same dimensions as the old series and the I / O modules of the new and old series are mounted on the base unit so that the installation area is not different between the new and old series. It enables the CPU module to control those I / O modules even if new and old series of I / O modules are mixed and attached to the base unit.

Although the present application includes a plurality of means for solving the above problems, an example of the programmable controller according to the present invention includes an expansion control module connected to a CPU module or a basic unit, and an I / O module as a base unit. Programmable controller connected to the CPU module and the I / O module for transmitting signals, wherein each slot to which the I / O module is connected is a connector for one series and the other It has a connector for series and one series of I / O modules or another series of I / O modules can be selected and connected in the slot, and one series connected with the connector for one series For the other series connected with the data bus for the other series and the connector for the other series A data bus and a data bus direction control circuit, and under control of the data bus direction control circuit, switching between the data bus for the one series and the data bus for the other series, the one connected to the slot Select a series of I / O modules or another series of I / O modules to exchange signals with the CPU module, and one of the series of I / O modules and the other series of I / O modules is And outputting a module select response signal in response to a module select request signal, and the data bus direction control circuit is responsive to the presence or absence of the module select response signal to output the data bus for the one series and the other. And the data bus for the series .

  In addition, another example of the programmable controller of the present invention is a programmable controller in which a CPU module and an I / O module are connected to a base substrate, and the base substrate includes one terminal and the other. The I / O module is connected to one of the one terminal or the other terminal, and the CPU module transmits a signal to the one terminal, and the transmitted When there is a response to the signal, it communicates with the I / O module connected to the one terminal, and when there is no response to the signal transmitted, it is connected to the other terminal It communicates with the I / O module.

  According to the present invention, in a different series of programmable controllers, an old series module can be used as it is in combination with a new series product.

It is an explanatory view of a programmable controller which is an embodiment of the present invention. It is an explanatory view showing composition of PLC of a general building block type. It is explanatory drawing which shows the external appearance of the new and old series I / O module product. It is explanatory drawing which shows the external appearance of PLC with which the I / O module of new and old series was mixed and mounted to the base unit which is embodiment of this invention. It is a time chart which shows the access specification of old series PLC.

  Before describing the mode for carrying out the present invention, a general procedure for using a PLC and a product configuration will be described.

  FIG. 2 shows the configuration of a building block type PLC system, and the PLC system is configured by devices called a basic base unit 1, a power supply module 2, a CPU module 3, and an I / O module 4. The basic base unit 1 fixes and mounts the power supply module 2, the CPU module 3 and the I / O module 4, and supplies the power supplied from the power supply module 2 to the CPU module 3 and the I / O module 4. The main role is to transmit control signals between the CPU module 3 and the I / O module 4.

  While at least one power supply module 2 and at least one CPU module 3 are mounted on the basic base unit 1, one to a plurality of I / O modules 4 are mounted according to the scale of the equipment to be controlled. The basic base unit 1 on which the CPU module 3 is mounted is called a basic unit.

  The number of I / O modules 4 that can be attached to the basic base unit 1 is generally about ten. If the number of I / O modules 4 mounted to the basic base unit 1 exceeds the number that can be mounted to the basic base unit 1, add the expansion base unit 10 and mount the expansion control module 5 instead of the CPU module 3; By connecting the basic base unit 1 of the basic unit and the expansion control module 5 with the expansion connection cable 6, the number of installed I / O modules 4 on the expansion base unit 10 can generally be expanded. is there. The expansion base unit 10 expanded is called an expansion unit.

  The PLC system configured according to the control scale operates by the program registered in the CPU module 3. The PLC user performs an operation to determine the next operation of the control target based on the input information taken from the input terminal of the I / O module 4, and conversely, the operation result of the I / O module 4 The equipment to be controlled is controlled by transmitting as a control signal from the output terminal. These input / output control signals are exchanged with the I / O module 4 via an I / O memory provided in the CPU module 3. It is necessary to assign the layout in the I / O memory according to the mounting position of the I / O module mounted on the basic base unit 1 and the information of the number of input / output signals that the I / O module can handle. It is called O-allocation, and the PLC user registers before programming.

  FIG. 3 is a view showing a dimensional comparison of I / O modules having equivalent functions in the new and old series of PLC product groups, as described in the problem to be solved by the present invention. The left figure shows the old series I / O module 7 and the right figure shows the new series I / O module 8. Due to the miniaturization of electronic components and the improvement of high-density mounting technology, PLC products are downsized year by year, and there are many that realize 50% or less in volume ratio between new and old series.

  Hereinafter, embodiments of the present invention will be described using the drawings.

  Figure 4 shows the power supply module 2, CPU module 3, old series I / O module 7, new series I / O module 8 to the basic base unit 1 of the type that can install a total of three new or old series I / O modules. It is a figure which shows a mode that was mounted. As shown in this figure, the slot in which the I / O module is installed has a slot in which either the old series I / O module 7 or the new series I / O module 8 is installed, and either series I There is a slot in which the / O module is not installed.

  FIG. 1 is a block diagram illustrating connectors, signal lines and the like constituting the basic base unit 1 of the present embodiment, and a broken line indicates a slot in which any one of new and old I / O modules is mounted.

A connector 21 for mounting the power supply module 2, a connector 22 for mounting the CPU module 3, a connector 23 for mounting the old series I / O module, and a new series I / O module are mounted on the base substrate 20. Connector 24 is provided. Also, the old series I / O data bus 25 for exchanging information between the old series I / O module and the CPU module 3, and the new series I for exchanging information between the new series I / O module and the CPU module 3. Data bus direction control circuit 27 which switches the input / output direction of old series data bus 25 and new series data bus 26 based on control of / O data bus 26 and CPU module 3, between CPU module 3 and new series I / O module Address data mixed data bus 28 for transmitting and receiving information, and a module select request signal (decoding an address signal designated when the CPU module 3 exchanges information with the I / O module) to indicate whether access to each slot is A decoder 29 is provided to generate the MS signal) 30-32. There. Reference numeral 33 denotes a module select response signal (MSACK signal) used between the old series I / O module and the CPU module 3.

  FIG. 5 is a time chart showing an access specification between the CPU module and the I / O module in the old series PLC. When the CPU module receives the information of the I / O module, it is read access, and conversely, when the CPU module passes the information to the I / O module, it is the write access. In the figure, the left side shows read access and the right side shows write access.

  When performing read / write access to an I / O module, the old series CPU module outputs a predetermined address in the I / O memory to the address bus while making the request signal MS_N signal corresponding to the slot to be accessed Low active. . If the I / O module attached to the corresponding MS_N signal determines that it is an access to itself, it outputs a response signal MSACK_N signal to the CPU module. By such a procedure, the CPU module and the I / O module exchange information while confirming each other's state.

  On the other hand, between the CPU module and I / O module of the new series, the control signal corresponding to the response signal MSACK_N used in the old series is not implemented, and information is transmitted using a general means of asynchronous access. I am exchanging.

  In this embodiment, a method for absorbing the difference in handshake means between the new and old series, and enabling the new series of CPU modules to exchange information in a state where the new and old series of I / O modules are mixed It demonstrates using FIG. 1 and FIG.

  The old series I / O module 7 is installed in the first slot from the left where the I / O module is installed, the new series I / O module 8 is installed in the second slot, and the I / O module is installed in the third slot The operation on the basic base unit 1 will be described in a situation where it is not performed.

  When the CPU module 3 receives information from the I / O module installed in the first slot (slot 0), the CPU module 3 outputs the I / O address to the address bus and further activates the MS signal 30 of the slot 0 Make it Since the old series I / O module 7 is mounted in the slot 0, the MSACK signal 33 is activated from the old series I / O module 7 after a certain period of time. When the data bus direction control circuit 27 detects that the MSACK signal 33 has become active, it determines that the old series I / O module is attached to the slot 0, and outputs it to the old series I / O data bus 25. The control data is controlled to be connected to the address data mixing data bus 28, and the data of the old series I / O module 7 is transmitted to the CPU module 3.

  On the other hand, when the CPU module 3 receives information from the I / O module installed in the second slot (slot 1), the CPU module 3 outputs the I / O address to the address bus, and further the MS signal 31 of slot 1 Activate Since the MSACK signal 31 does not become active even if a certain time passes, the data bus direction control circuit 27 determines that the new series I / O module is installed in the slot 1, and the new series I / O The data output to the data bus 26 is controlled to be connected to the address data mixing data bus 28, and the data of the new series I / O module 8 is transmitted to the CPU module 3.

  Although the basic base unit provided with the CPU module has been described in FIG. 1, the present invention can be similarly applied to an extension base unit provided with an extension control module.

  In this embodiment, a CPU module and an I / O module are connected to a base unit, and the CPU module and the I / O module are programmable controllers that transmit signals, and the I / O module is connected. Each slot has a connector for one series and a connector for the other series, and select and connect one series of I / O modules or another series of I / O modules to the slots It was possible. Therefore, in different series of programmable controllers, old series modules can be used in combination with new series products.

  Also, according to the presence or absence of the module select response signal, the data bus direction control circuit switches between the data bus for one series and the data bus for the other series, and one series of I / O connected to the slot. Since modules or other series of I / O modules are selected to exchange signals with the CPU module, it is easy to detect which series of I / O modules are connected.

  The first embodiment detects whether the new series of I / O modules is connected or the old series of I / O modules is connected depending on the presence or absence of the response signal MSACK signal. The connector provided is provided with connection detection means for detecting connection of the I / O module.

  A connection detection means is provided for detecting whether or not the I / O module is connected to one or both of the connector 24 for the new series and the connector 23 for the old series. As the connection detection means, any means such as an electrical switch means or an optical detection means may be used.

  The data bus direction control circuit determines which of the new series of I / O modules and the old series of I / O modules is connected by the detection signal from the connection detection means, and as in the first embodiment, The data bus 26 for series and the data bus 25 for old series are switched and connected to the address data mixed data bus 28.

  According to this embodiment, since the connector provided in the slot is provided with the connection detection means for detecting the connection of the I / O module, it is possible to use in combination the two series, all of which do not have the response signal MSACK signal. it can.

1 Basic base unit 2 Power supply module 3 CPU module 4 I / O module 5 Expansion control module 6 Expansion connection cable 7 Old series I / O module 8 New series I / O module 10 Expansion base unit 20 Base board 21 Power module connector 22 CPU Module connector 23 old series I / O module connector 24 new series I / O module connector 25 old series I / O data bus 26 new series I / O data bus 27 data bus direction control circuit 28 address / data mixed bus 29 decoder 30, 31, 32 Module select request signal (MS signal)
33 Module select response signal (MSACK signal)

Claims (4)

A programmable controller in which an expansion control module connected to a CPU module or a basic unit, and an I / O module are connected to a base unit, and the CPU module and the I / O module transmit signals.
Each slot to which the I / O module is connected has a connector for one series and a connector for the other series,
Select and connect one series of I / O modules or another series of I / O modules to the slot,
A data bus for one series connected with a connector for the one series;
A data bus for another series connected with a connector for the other series;
Equipped with a data bus direction control circuit,
Under the control of the data bus direction control circuit, the data bus for one series and the data bus for the other series are switched, and one series of I / O modules or other series connected to the slot is selected. Select an I / O module and exchange signals with the CPU module,
One of the one series of I / O modules and one of the other series of I / O modules outputs a module select response signal in response to a module select request signal,
The programmable controller, wherein the data bus direction control circuit switches between the data bus for one series and the data bus for the other series according to the presence or absence of the module select response signal. A programmable controller in which an expansion control module connected to a CPU module or a basic unit, and an I / O module are connected to a base unit, and the CPU module and the I / O module transmit signals.
Each slot to which the I / O module is connected has a connector for one series and a connector for the other series,
Select and connect one series of I / O modules or another series of I / O modules to the slot,
A data bus for one series connected with a connector for the one series;
A data bus for another series connected with a connector for the other series;
Equipped with a data bus direction control circuit,
Under the control of the data bus direction control circuit, the data bus for one series and the data bus for the other series are switched, and one series of I / O modules or other series connected to the slot is selected. Select an I / O module and exchange signals with the CPU module,
One or both of the connector for one series and the connector for the other series have connection detection means for detecting whether or not the I / O module is connected,
The data bus direction control circuit controls the data bus for the one series and the other series according to which one of the one series of I / O modules and the other series of I / O modules is connected. A programmable controller characterized by switching between a data bus and a data bus. The programmable controller according to claim 1 or 2
A programmable controller characterized in that the one series of I / O modules is a new series of I / O modules, and the other series of I / O modules is an old series of I / O modules. A programmable controller in which a CPU module and an I / O module are connected to a base substrate,
The base substrate has one terminal and another terminal,
The I / O module is connected to either the one terminal or the other terminal,
The CPU module transmits a signal to the one terminal,
If there is a response to the transmitted signal, it communicates with the I / O module connected to the one terminal,
A programmable controller characterized in that it communicates with the I / O module connected to the other terminal when there is no response to the transmitted signal.

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