JP2000207373A - Process input-output device and method for controlling it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further improve reliability of a process control system. SOLUTION: In a remote process input-output device 61 connected to control MPUs 4a and 4b through IO links 5a and 5b, the coexistence of single/duplex in the same shelf 61 is made possible by providing an IO module doubling system which does not require any operation/standby switching signal between paired IO modules and the operation/standby switching between the paired IO modules is performed by means of a duplex IO bus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly reliable distributed control system, and more particularly, to a dual process input / output device that directly interfaces with a process in a controller and a control method thereof.

[0002]

2. Description of the Related Art FIG. 7 shows an example of the configuration of a distributed control system.

[0003] 1 is a man-machine interface device, 2 is a control LAN, and 31 to n are controllers.

[0004] In a distributed control system, a plurality of controllers (several tens in the case of a large scale) which are distributed and installed are connected by a control LAN, and these are managed by one to several man-machine interface devices. Such a system.

FIG. 8 shows a configuration example of the controller 31 shown in FIG.

[0006] 4 is a control MPU, 5 is an IO link, 61 to 61
n is a process input / output device.

The control MPU 4 includes a process input / output device 61
To n via the IO link 5.
Such a controller 31 is generally required to have high reliability.

FIG. 9 shows an example of increasing the reliability of the controller 31.

4a and 4b are control MPUs, and 5a and 5b are I
O links 61 to n are process input / output devices.

In this example, the control MP
U4a, 4b and IO links 5a, 5b are duplicated. Process input / output devices 61 to n are connected to the IO links 5a and 5b, respectively.

FIG. 10 shows the control MPU 4 of FIG.
1 shows an example of the configuration of a process input / output device that supports duplication of IO links 5a and 5b with IO links 5a and 5b.

Reference numerals 5a and 5b denote IO links, 7a and 7b denote transmission control modules, 8 denotes an IO bus, and 91 to n denote IO modules.

The transmission control modules 7a and 7b interface with the IO links 5a and 5b and the IO bus 8,
It relays data exchange between the control MPUs 4a and 4b and the IO modules 91 to n. On the other hand, IO module 9
1 to n interface directly with the process and convert between analog and digital quantities.

In this example, control MPUs 4a, 4b and IO
The transmission control modules 7a and 7b are duplicated corresponding to the duplication of the links 5a and 5b. Accordingly, the transmission control modules 7a, 7b are controlled in response to the switching between the operation / standby of the control MPUs 4a, 4b and the IO links 5a, 5b.
b is switched.

FIG. 11 shows not only the transmission control modules 7a and 7b shown in FIG.
4 shows a configuration example of a process input / output device when the O bus is duplicated.

Reference numeral 61 denotes an IO shelf of a process input / output device, which has mounting slots for two transmission control modules 7a and 7b and 16 IO modules. This I
One O-shelf constitutes one process input / output device. 8a and 8b are IO buses and 91a and 9
1b to 98a and 98b are IO modules, which are duplicated.

Slot numbers 00 and 01, 02 and 03,...
14 and 15 each have the same type of IO module 9
., 98 are duplicated with pairs a and b, respectively. The pair a and b have one running and the other waiting, and both are connected to a process. The input signal from the process is input to both the operation and the standby, and the signal output to the process is performed only by the operation side.

[0018]

As shown in FIG. 11, the control MPUs 4a and 4b, the IO links 5a and 5b, the transmission control modules 7a and 7b, IO module 91-
n, and the IO buses 8a and 8b are duplicated.

However, a conventional process input / output device (FIG. 1)
1) has the following problems.

(1) The operating / standby IO module pair must be mounted in an adjacent slot of the IO shelf, and the duplexing slot must be fixed in advance.
As a result, single and duplex cannot be freely mixed and mounted in the same IO shell, and the mounting slots of the IO shelf cannot be used efficiently.

(2) There is an operation / standby switching signal between the operation / standby IO module pair, and this portion is not duplicated. As a result, if that part breaks down, duplication becomes meaningless and reliability is lacking.

(3) The IO bus is a so-called single master bus in which only the transmission control module is used as a master and a plurality of IO modules are used as slaves. The load on the transmission control module is heavy. As a result, when trying to improve the performance of the IO link or the IO bus, the performance of the transmission control module may be a bottleneck.

(4) For the same reason as in (3), when equalizing the data of the duplexed output module pair, the transmission control module must intervene to equalize the data, and the data between the module pair must be equalized. Time lag, and perfect synchronization cannot be achieved. As a result, this out-of-sync is a serious problem in processes where the active module fails and the standby needs to recover immediately.

Accordingly, an object of the present invention is to provide a process input / output device and a process input / output device capable of further improving the reliability of a process control system by using a multi-master serial bus in multiplexed remote process input / output control. It is to provide a control method.

[0025]

SUMMARY OF THE INVENTION The present invention is a process input / output device for exchanging data with a control unit accompanying multiplexing process control, and is connected to the control unit via an input / output link. A transmission control module, a plurality of input / output modules on which process control is performed, an input / output bus connecting the transmission control module and the plurality of input / output modules as a multi-master configuration, the transmission control module and the plurality of Storing means for storing the input / output modules, and multiplexing status information indicating a mode related to the multiplexing process from each of the input / output modules at a fixed period;
Means for notifying the transmission control module, means for aggregating the respective multiplexing status information notified to the transmission control module to create aggregated information, means for sending the aggregated information to the control unit, Means for creating multiplexing operation designation information indicating a mode related to a multiplexing process of each of the input / output modules, based on the process control information transferred from the control unit to the transmission control module; Means for transferring from the transmission control module to each of the input / output modules, and a process input / output device is constituted by performing a multiplexing process in one storage means.

The present invention also relates to a process input / output control method for exchanging data accompanying a multiplexing process control with a control unit, the multiplexing process showing a mode relating to a multiplexing process from a plurality of input / output modules. A step of notifying the transmission control module of the status information at regular intervals, a step of aggregating the multiplexed status information notified to the transmission control module to create aggregated information, and transmitting the aggregated information to the control unit. Sending, and creating process control information for multiplexing process control of the input / output module in the control unit, based on the process control information transferred from the control unit to the transmission control module, Creating multiplexing operation designation information indicating a multiplexing process of each input / output module; To provide a process input-output control method for performing a multiplexing process by comprising the step of transferring the constant information from the transmission control module to each output module.

Here, the multiplex status information is information indicating operation / standby and single / duplex processing, and the multiplex operation designation information is a pair in the case of single / duplex designation and duplex. And information indicating designation of operation / standby of the duplex pair.

In the case where the input / output modules are duplicated, each duplicated input / output module is connected not only to the transmission control module but also to a paired input / output module via the input / output bus. Means for notifying the multiplexing status information indicating operation / standby and single / duplex at regular intervals, and detecting that the multiplexing status information of the operating side input / output module is interrupted by the input / output module on the standby side. Means for determining that the input / output module on the operating side is faulty and taking over the operation processing, and the input / output module on the operating side notifies the input / output module on the standby side of the multiplexing status information. When the multiplexing status information cannot be notified to the standby input / output module, It may comprise a means for stopping the output of the process by.

When the input / output bus is duplicated and the multiplex status information is notified from the active input / output module to the standby input / output module, the standby input / output module transmits the multiplex status information. If the reception is not confirmed, the means for notifying the multiplexing status information using another duplicated I / O bus, and the standby I / O module being connected to the multiplexed I / O bus from either of the duplicated I / O buses Means for determining that the active input / output module has failed when the activation status information cannot be received.

In the case where the input / output module is duplicated, the transmission control module transfers output data via the input / output bus only to the active input / output module of the paired input / output modules. When,
The operating-side input / output module transfers the output data to a standby-side input / output module, and after receiving a response from the standby-side input / output module, processes the output data. Data processing makes it possible to equalize data between active / standby input / output modules.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

(First Example) First, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a configuration example of a process control system according to the present invention. The same parts as those in FIGS. 7 to 11 are denoted by the same reference numerals.

In the controller 31 connected to the control LAN 2, a process input / output control device 61 is connected to the control MPUs 4a and 4b via IO links 5a and 5b. The process input / output control device 61 shown in FIG. 1 shows a state before the setting of duplexing by the control MPUs 4a and 4b.

The control MPUs 4a and 4b perform calculations for process control, and perform a plurality of distributed control (for example, n
= 32) process input / output devices 61 and IO links 5
Data exchange is performed via a and 5b. The transmission control modules 7a and 7b are connected to IO modules 91 to 105 via IO buses 8a and 8b. In these IO modules 91 to 105, there is no fixed connection for determining operation / standby between the duplicated IO module pairs as shown in FIG. Also, I
The O buses 8a and 8b are serial buses capable of a multi-master configuration as represented by a backplane environment of IEEE 1394 to 1995.

The process input / output device 61 is connected to various sensors and actuators of the process via input / output terminals 111 to 125, and converts the analog value of the process into a digital value that can be calculated by the control MPUs 4a and 4b. Convert.

(Process Control) Next, the process control of the present system will be described.

In FIG. 1, each I0 module 91-1
When the initial processing is completed after the reset start, status information as shown in FIG.
transmission control modules 7a, 7b at regular intervals via
b. Note that all the IO modules 91 to 1
05, after the reset start, the transmission control module 7
Until designated by a and 7b, the single and standby state is maintained, and the output IO module does not output to the process.

Here, the status information will be described. This status information is configured as one word information of 0 to 15 bits. The ID (8 bits) indicates a module identification number. D (1 bit) indicates single / duplex (0: single, 1: duplex). M
(1 bit) indicates standby / operation (0: standby,
1: operation). SLOT (4 bits) indicates the mounting slot number.

Next, the transmission control modules 7a and 7b
The slot mounting information 1 as shown in FIG. 4 is created based on the status information of each of the IO modules 91 to 105. The basic configuration of the slot mounting information 1 is as follows.
This is the same as the status information in FIG.

The control MPUs 4a, 4b
a, 5b, the slot mounting information 1 is collected, and
The mounting state of each of the IO modules 91 to 105 in the 0 shelf is grasped.

The control MPUs 4a and 4b transmit the transmission control modules 7a and 7b via the IO links 5a and 5b.
IO modules 91 to 1 in one IO shelf
05, the single / duplex designation, the duplex pair designation, and the operation / standby designation information in the case of the duplex are notified.

Thus, the transmission control modules 7a, 7
b generates slot mounting information 2 as shown in FIG. 5 based on the notified specification information. In the example of FIG.
Slot (SLOT) numbers 01 and 02 and 14 and 15
Of IO modules are designated as a duplex pair. The basic configuration of the slot mounting information 2 is the same as the status information of FIG.

Each of the IO modules 91 to 105 has an IO
When the module is designated for single operation, information of one word in slot units of FIG. 5 to which M and D bits are added as operation designation information of the slot is transmitted from the transmission control modules 7a and 7b to the IO buses 8a and 8b. Sent via

When the IO module operates in duplicate,
In addition to the operation setting information of the slot, operation setting information of the slot number of the partner of the duplex pair is also transmitted to the IO module. For example, in the example of FIG.
, The operation designation information of the slot numbers 01 and 02 is transmitted.

In the case of a single operation, each of the I0 modules 91 to 105 immediately shifts to an operating state after operation setting, and in a case of a duplex operation, shifts to an operating or standby state according to operation setting information.

FIG. 2 shows a connection state after the duplex setting by the control MPUs 4a and 4b.

The IO module 92 in the slots 01 and 02
a, 92b and the IO modules 104a, 104b of the slots 14, 15 are duplicated. Due to this duplication, the input / output terminals 112 and 124 are each short-circuited. In the case of duplexing, output to the process is performed only by the IO module on the operating side.

In this example, the duplex pair is specified in the adjacent slot because the input / output terminal can be short-circuited by using a metal fitting or the like. No need to be.

(Second Example) Next, a second embodiment of the present invention will be described with reference to FIG. The description of the same parts as those in the above-described example is omitted, and the same parts are denoted by the same reference numerals.

FIG. 6 shows a configuration example of the output stop circuit 200 of the operating IO module.

The output stop circuit 200 includes a one-chip microcomputer 201, a 4-bit counter 202, and an inverter 20.
3 and output FET (Field Effect Transistor) 2
04. 4-bit counter 20
2 constitutes a watchdog timer.

Thus, the one-chip microcomputer 201 has one
If the load (L0) signal of the counter is set to Low within 0 ms, no overflow occurs. If it cannot be made low, the ripple carry (RCO) signal becomes valid, the counter stops, and the output FET 204 stops outputting. Thus, the output stop circuit 200 stops the output due to the overflow of the watchdog timer.

In the present embodiment, the following control is performed using such an output stop circuit 200.

The IO module designated for single operation transmits the status information shown in FIG. 2 only to the transmission control modules 7a and 7b at regular intervals via the IO buses 8a and 8b. On the other hand, the IO module specified for duplication also has the IO module of the other
Via the IO buses 8a and 8b, a fixed period (for example, 10 m
Send in s).

The IO module on the standby side always monitors the status information, and if the IO module on the active side does not transmit the status information for a predetermined period or more, the IO module on the active side is regarded as a failure and Becomes active and takes over the processing.

On the other hand, the operating-side IO module clears the watchdog timer in synchronization with the transmission of the status information, and when the watchdog timer overflows, when the IO module is the output module,
Stop output to the process by hardware.

(Third Example) Next, a third embodiment of the present invention will be described. The description of the same parts as those in the above-described example is omitted, and the same parts are denoted by the same reference numerals.

When the active IO module transmits status information to the standby IO module via the IO bus at a constant period, if only one IO bus is used, the IO
If the bus breaks down, even if the working side is normal, the status information cannot be received, so that the inconvenience that the standby side regards the failure as the working side occurs.

Therefore, in this example, the IO buses 8a and 8b are duplicated, and the standby IO module is connected to the active IO bus.
If you no longer receive module status information,
Waiting for status information from the other bus, control is performed such that when reception from either of the two buses becomes impossible, the IO module on the operating side is regarded as a failure.

When the IO module on the operating side cannot receive the acknowledgment of the status information transmitted by itself on the IO module on the standby side, it immediately transmits the status information using the other bus.

According to such a method, the probability that two duplicated buses simultaneously fail becomes very small.
The above disadvantage can be solved.

It is to be noted that IO noise is caused by transient noise or the like.
In order to save the case where the communication of the bus temporarily becomes an error, there is a method in which the IO module on the standby side detects the interruption of the status information a plurality of times and regards it as the failure on the active side only in this case. Since it takes several tens of milliseconds from the failure of the active IO module until the standby IO module takes over the process, this method is limited to applications where it is permissible.

(Fourth Example) Next, a fourth embodiment of the present invention will be described. The description of the same parts as those in the above-described example is omitted, and the same parts are denoted by the same reference numerals.

The transmission control modules 7a and 7b grasp the mounting state of the IO modules 91 to 105 in one IO shelf, and whether the IO modules 91 to 105 are single or duplicated, , The output data received from the control MPUs 4a and 4b via the IO links 8a and 8b is transmitted.

If the IO module is single, the output operation is started immediately. If the IO module is duplexed, the output data is transmitted to the IO module on the standby side, and the output operation is performed after waiting for the reception confirmation response. Start.

According to such a method, the IO of the duplex pair
The modules can start the output operation almost in synchronization with each other. If the IO module on the operating side fails, the same output data is created in the IO module on the standby side almost at the same time. . In addition, I on the standby side
The O module creates the same output data as the operating IO module, but does not output to the process.

In each of the above examples, the duplexing method is described as an example of the multiplexing process. However, the present invention is not limited to this duplexing, and is applicable to other multiplexing methods. It is possible.

[0069]

As described above, according to the present invention,
In a remote process input / output device connected to a control MPU via an IO link, a single / duplex mixture in the same shelf is provided by providing a duplicated IO module system in which an operation / standby switching signal between IO module pairs is unnecessary. , The IO shelf can be used efficiently.

According to the present invention, the operation / standby switching signal is eliminated, and the operation / standby switching between the IO module pairs is performed using the duplicated IO bus, so that the reliability of the system is further improved. Can be done.

Further, according to the present invention, the IO bus is a multi-master serial bus, and the IO module itself performs data equalization between the duplicated IO modules and collects the mounting status of the IO modules. As a result, the load on the transmission control module can be reduced, and the IO link and I
The performance of the O bus can be improved.

Further, according to the present invention, the equalization of the data between the duplicated output modules is performed between the output modules, and the active module confirms the reception of the equalized data of the standby module. Since the processing of the data received from the transmission control module is started, the data can be synchronized between operation and standby.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a process control system before a duplex setting according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a process control system after duplex setting according to the first embodiment of this invention;

FIG. 3 is an explanatory diagram showing status information of each IO module.

FIG. 4 is an explanatory diagram showing slot mounting information 1.

FIG. 5 is an explanatory diagram showing slot mounting information 2.

FIG. 6 is a block diagram illustrating a configuration example of an output stop circuit according to a second embodiment of the present invention;

FIG. 7 is a block diagram illustrating a configuration example of a distributed control system.

FIG. 8 is a block diagram illustrating a configuration example of a controller.

FIG. 9 is a block diagram illustrating an example of increasing the reliability of a controller.

FIG. 10 is a block diagram showing a configuration example of a process input / output device corresponding to a duplex control MPU and IO link.

FIG. 11 is a block diagram illustrating a configuration example of a process input / output device in which an IO module and an IO bus are also duplicated.

[Explanation of symbols]

 4a, 4b Control MPU 5a, 5b IO link 7a, 7b Transmission control module 8a, 8b IO bus 31 Controller 61 Process input / output device (IO shelf) 91-105 IO module

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 13/00 301 G06F 13/00 301P 13/12 310 13/12 310B F term (Reference) 5B014 EA04 EA05 EB05 EB01 GA08 GA60 GD04 GD19 GD25 GD32 HC03 5B034 BB02 CC01 CC05 CC06 DD01 DD06 5B045 AA05 JJ24 JJ25 JJ28 5B083 AA05 BB03 CC09 CD11 DD11 EE07 5H209 CC01 CC09 CC13 DD11 DD16 EE11 GG16 HH04 HH33 SS01

Claims (10)

[Claims] 1. A process input / output device for performing data exchange accompanying a multiplexing process control with a control unit, comprising: a transmission control module connected to the control unit via an input / output link; A plurality of input / output modules to be executed; an input / output bus for connecting the transmission control module and the plurality of input / output modules as a multi-master configuration; and a storage unit for storing the transmission control module and the plurality of input / output modules. Means for notifying the transmission control module of multiplexing status information indicating a mode related to a multiplexing process from each of the input / output modules at regular intervals, and the respective multiplexing status information notified to the transmission control module. Means for aggregating to create aggregated information; means for sending the aggregated information to the control unit; Means for creating multiplexing operation designation information indicating a mode related to a multiplexing process of each of the input / output modules based on the process control information transferred from the communication control module to the transmission control module; and Means for transferring data from a module to each of the input / output modules, and performing a multiplexing process in one storage means. 2. The multiplexing status information is information indicating operation / standby and single / duplex processing, and the multiplex operation designation information is single / duplex designation,
2. The process input / output device according to claim 1, wherein the information is information indicating designation of a pair in the case of duplexing and designation of operation / standby of the duplexing pair. 3. When the input / output module is duplicated, each duplicated input / output module is connected not only to the transmission control module but also to a paired input / output module via the input / output bus. Means for notifying the multiplexing status information indicating operation / standby and single / duplex at regular intervals, and that the multiplexing status information of the operating side input / output module is interrupted by the standby side input / output module. When detecting, the operation side input / output module is determined to be faulty and means for taking over the operation process, and the operation side input / output module is the multiplexing status information to the standby side input / output module. When the notification of the multiplexing status information to the input / output module on the standby side is impossible, the timer 3. The process input / output device according to claim 1, further comprising means for stopping output to a process by an imager. 4. In a case where the input / output bus is duplicated and the multiplexing status information is notified from an input / output module on the working side to an input / output module on the standby side, the input / output module on the standby side sets the multiplexing status If the reception of the information cannot be confirmed, means for notifying the multiplexing status information using another duplicated I / O bus, and the standby-side I / O module may be connected to either of the duplicated I / O buses. 2. A means for judging a failure of the input / output module on the operation side when the multiplexing status information cannot be received.
Or the process input / output device according to 2. 5. In a case where the input / output module is duplicated, the transmission control module transfers output data via the input / output bus only to an operating input / output module of the paired input / output modules. Means for performing, the operating-side input / output module transfers the output data to a standby-side input / output module, and after confirming a reception response from the standby-side input / output module, processing the output data. 3. The process input / output device according to claim 1, wherein data equalization between active / standby input / output modules is performed by processing the output data. 6. A process input / output control method for exchanging data accompanying control of a multiplexing process with a control unit, wherein multiplexing status information indicating a mode related to a multiplexing process from a plurality of input / output modules is defined. A step of notifying the transmission control module in a cycle, a step of aggregating the multiplexed status information notified to the transmission control module to create aggregated information, and a step of sending the aggregated information to the control unit. Generating a process control information for performing multiplexing process control of the input / output module in the control unit; and executing the input / output module based on the process control information transferred from the control unit to the transmission control module. Creating multiplexing operation designation information indicating a mode related to a module multiplexing process; Transferring from the transmission control module to each of the input / output modules to perform a multiplexing process. 7. The multiplexing status information is information indicating operation / standby and single / duplex processing, and the multiplexing operation designation information is single / duplex designation,
7. The process input / output control method according to claim 6, further comprising information indicating designation of a pair in the case of duplexing and designation of operation / standby of the duplexing pair. 8. When the input / output module is duplicated, each duplicated input / output module is connected not only to the transmission control module but also to a paired input / output module via the input / output bus. Also, the step of notifying the multiplexing status information indicating the operation / standby and the single / duplex at regular intervals, and the fact that the multiplexing status information of the operating side input / output module is interrupted by the standby side input / output module. When detecting, the step of taking over the operation processing by determining that the input / output module on the operation side is faulty, and the input / output module on the operation side, the multiplexing status information to the input / output module on the standby side When the notification of the multiplexing status information to the input / output module on the standby side is impossible, the timer 8. The process input / output control method according to claim 6, further comprising a step of stopping output to a process by an image. 9. In a case where the input / output bus is duplicated and the multiplexing status information is notified from an active input / output module to a standby input / output module, the standby input / output module is configured to receive the multiplex status. If the reception of the information cannot be confirmed, a step of notifying the multiplexing status information by using another duplicated I / O bus, and the standby-side I / O module is connected to either of the duplicated I / O buses. 7. A step of determining that the input / output module on the operation side has failed when the multiplexing status information cannot be received.
Or the process input / output control method according to 7. 10. When the input / output module is duplexed, the transmission control module transfers output data via the input / output bus only to the active input / output module of the paired input / output modules. Performing the step of transferring the output data to the input / output module on the standby side, and processing the output data after confirming the reception response from the input / output module on the standby side. 8. The process input / output control method according to claim 6, wherein data equalization between active / standby input / output modules is performed by processing the output data.