JP2002232439A - Data communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the intelligence of a driver itself and to simultaneously process requested access from a plurality of APs in data communication from a field control station to an I/O module. SOLUTION: A distribution type control system is provided with the field control station communicating with an information command station through a control bus, the I/O module communicating with the field control station through an I/O bus and a driver means which communicates data between one of a plurality of applications and the I/O module by connecting a line and is arranged in the field control station. The driver means is provided with a means for managing connection request information from the applications and the use state information of the line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information and command station (ICS) via a control bus.
Field Control Station (FC)
S) and an I / O that communicates with the FCS via an I / O bus.
In a distributed control system including an O module (IOM), the present invention relates to data communication by request-type access between a plurality of applications in the FCS and the IOM.

[0002]

2. Description of the Related Art FIG. 7 is a system configuration diagram of a distributed control system (hereinafter, DCS) comprising general components. 1 is an information / command station (hereinafter referred to as IC) having a human interface function.
S), 2 is a control bus called Vnet, 3 is this Vn
It is a field control station (hereinafter, FCS) that communicates with the ICS 1 via the E.

[0003] Reference numeral 4 denotes an I / O bus, and reference numeral 5 denotes an I / O module (hereinafter referred to as IO) for communicating with the FCS 3 via the I / O bus.
M) and 6 are field buses, and 7 is a field device that communicates with the IOM 5 via the field bus.

In the FCS 3, reference numeral 8 denotes a request receiving unit of an upper station (ICS), AP1, AP2,.
Is a plurality of applications (hereinafter referred to as APs) to be requested by the upper station, and 9 is a driver means for securing a line for data communication with a specific IOM 5 in response to a request from these APs.

[0005] One AP of FCS by request type access
A procedure for downloading data from a to a specific IOM will be described with reference to FIG. In order to perform request-type access, the AP first issues a connection request for securing a communication line to the driver 9.

[0006] The driver 9 returns the result of the connection processing to the IOM 5 to the higher-level AP. When it is confirmed that the line has been connected, the upper AP sequentially processes data transmission and reception, and when all processes are completed, issues a line disconnection request to the driver 9 and ends a series of operations. .

[0007]

In the conventional IOM, F
Since there is no function to identify multiple higher-level APs in the CS, once one line is secured, that line must be used exclusively by that AP until the data communication processing of the AP is completed and disconnected. Thus, request-type access is realized.

Therefore, the upper AP needs to perform exclusive processing of the request before making its own connection request to the driver, or to restrict the operation for the user.

[0009] There is provided an IOM of a type in which the IOM standard is open and unified, and the IOM recognizes a higher-order AP, and can process several processes in parallel unless requested by the same AP. When a type of IOM is adopted, an architecture is required that monitors the line usage state, receives a plurality of AP requests simultaneously, and performs data communication.

An object of the present invention is to realize a data communication device capable of simultaneously processing requests from a plurality of APs by enhancing the intelligence of the driver means.

[0011]

In order to achieve the above object, a feature of the first aspect of the present invention is that a field control station which communicates with an information / command station via a control bus; An I / O module that communicates with the field control station via an I / O bus; and a line connection between one of the plurality of applications and the I / O module to execute data communication between the two. In the distributed control system including the driver provided in the above, the driver is provided with means for managing connection request information from the plurality of applications and use status information of the line.

According to a second aspect of the present invention, when the data communication between one of the application and the I / O module is terminated based on the connection request information and the line use state information, When there is a connection request from another application, the connection of the line is maintained, the data communication between the other application and the I / O module is continued, and the connection waits when this data communication is completed. If there is no request application, the point is to execute the processing for disconnecting the line connection.

A feature of the present invention is that the line use state information indicates a transition state of line not used, line connection waiting, connection confirmation waiting, line connection, line disconnection waiting, disconnection confirmation waiting. It is in the point comprised.

According to a fourth aspect of the present invention, the connection request information is incremented each time a connection request from the application is generated, and is decremented each time data communication of the application in use of the line is terminated. In the configured point.

According to a fifth aspect of the present invention, when the data communication between one of the application and the I / O module is terminated based on the connection request information and the line use state information, If there is a connection request from another application to the application, apparent line disconnection information is returned to the application for which data communication has been completed, and the other application and the I / O are maintained while maintaining the line connection state. If the data communication process between the O modules is continued and there is no connection request application to wait when the data communication is completed, the process of disconnecting the line connection between the I / O modules is executed. .

A feature of the present invention is that the I / O module has a function of identifying a plurality of applications in the field control station.

A feature of the present invention is that a line connection between the driver means and the I / O module is a plurality of channels.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram of a distributed control system to which the present invention is applied. The same components as those described with reference to FIG. The feature of the present invention lies in the configuration of the driver means 9, which enhances the intelligence of the driver itself and enables simultaneous processing of requests from a plurality of APs.

In the driver means 9, reference numeral 10 denotes an IOM from a plurality of applications AP1, AP2,.
5 is a request access receiving unit, 11 is a driver 9 and IOM
5 is an IOM access interface (I / F) processing unit that performs the access processing of No. 5.

Reference numeral 12 denotes a request-specific processing unit, and 1 according to the priority order of the APs received by the request access receiving unit 10.
When one access process is completed, the access of the new AP is changed to the IOM access interface (I / F) processing unit 11.
Pass to. Reference numeral 13 denotes a periodic processing unit, which performs periodic data communication with the IOM 5 not based on the access requested by the AP.
This is executed via the M access interface (I / F) processing unit 11.

Reference numeral 14 denotes a resource management table for each request, and 15 denotes a resource management table for each line. Both of these management tables are management means for realizing the functions of the present invention. FIG.
This is information in a card provided for each OM, and is indicated by a table in which the resource management table for each request and the resource management table for each line are integrated.

The IOM of the card is specified by the node number and the slot number of the node. This IOM
Has a line connection capability of four channels, and the connection state of each channel line is reflected in the upper area (A) of the table. In the lower area (B) of the table, the number of resources (AP) used for each channel line is reflected.

FIG. 3 is a state transition diagram for reflecting the connection state of each channel in the table of FIG. (A) to (F) show state names, and FIG. 4 shows the correspondence between each state name and its meaning.

The line connection waiting state (A) indicates a state from when the line connection processing is performed to when the confirmation processing is performed. The connection confirmation waiting state (B) indicates a state from when the connection confirmation processing is performed to when the result is obtained. Line connection status (C)
Indicates a state during transmission or reception request. The line disconnection wait state (D) indicates a state from when the line disconnection process is performed to when the confirmation process is performed. The disconnection confirmation waiting state (E) indicates a state from when the disconnection confirmation processing is performed to when the result is obtained. The line unused state (F) indicates a steady state in which the line is not used by the driver.

FIG. 5 is a flowchart showing a signal processing procedure for managing a table reflecting the number of resources using the line for each channel. FIG. 5A shows a request access from a new upper AP. (B) is a processing flow when the data communication of the connected AP ends and a line disconnection request occurs.

In the processing flow (A), the line status management table of the connection destination IOM is referred to by the access request from the upper AP, and if the line is not used, the connection process for the IOM is executed and then the line use state is changed. Then, the counter indicating the use state is incremented, the connection completion is notified to the upper AP, and the line connection request processing is terminated. If the line is in use, the connection processing jumps to increment the counter, and the upper AP is incremented. And notifies the connection completion to end the line connection request processing.

In the processing flow (B), the line status management table of the IOM to be disconnected is referred to by the disconnection request from the upper AP. Is executed, the line use state is changed, the counter indicating the use state is decremented, the disconnection completion is notified to the upper-level AP, and the line disconnection request processing is terminated. When the content of the use state counter is 1 or more, In the disconnection processing, the counter jumps and decrements the counter, notifies the upper AP of the connection completion, and ends the line connection request processing.

Further, in the processing flow (B), the upper AP
In response to the disconnection request, the line state management table of the disconnection destination IOM is referred to. If the line is in an unused state, the counter decrement is jumped, the connection completion is notified to the upper AP, and the line connection request processing is terminated. .

As described above, according to the present invention, when there is a line connection request from a plurality of APs for one line, the driver executes a connection process to the IOM according to the line connection request generated first. Thereafter, when a connection request is issued from another AP, the use state is checked with the line management information, and if the line is already connected, the apparent line connection completion is immediately returned to the upper AP.

Conversely, when the driver receives the line disconnection request, the driver checks the use state with the line management information and
If P is using the line (counter value is 2 or more), the counter is decremented and the upper AP is immediately notified of the apparent disconnection of the line to the upper AP.
If no other AP is used (counter value is 1) I
A circuit disconnection process is performed on the OM.

FIG. 6 is an explanatory diagram showing a communication procedure diagram for downloading data from the FCS to a specific IOM for a plurality of simultaneous request type accesses A and B.
First, the line connection processing of A is completed, and data is being transmitted (A2)
When a connection request for B (B1) is generated, the connection confirmation is immediately returned to B without performing a new line connection process.

In response to A's line disconnection request (A4), I
Immediately returns the apparent disconnection confirmation to A without performing the line disconnection process to the OM. B line disconnection request (B
For 3), a line disconnection process with the IOM is executed and B
Reply to disconnection confirmation.

[0033]

As is apparent from the above description,
According to the present invention, a higher-level AP can issue a line connection / line disconnection request at an arbitrary timing irrespective of the use state of the line of the IOM, so that the creation of the AP can be simplified.

Further, when the AP issues a connection request, the connection state can be checked with the line management information, so that a quick response can be returned to an already connected state. On the other hand, in the case of a line disconnection request, it is possible to prevent the line disconnection process from being executed by mistake when another AP is using the line.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a distributed control system to which the present invention is applied.

FIG. 2 is a table showing information in a card provided for each IOM in the present invention.

FIG. 3 is a state transition diagram for reflecting a connection state for each channel in the present invention.

FIG. 4 is an explanatory diagram showing a correspondence relationship between each state name and its meaning in the table of FIG. 2;

FIG. 5 is a flowchart illustrating a signal processing procedure for managing a table reflecting the number of resources using a line for each channel in the present invention.

FIG. 6 is an explanatory diagram showing a communication procedure diagram in a case where data is downloaded from the FCS to a specific IOM for a plurality of simultaneous request type accesses in the present invention.

FIG. 7 is a system configuration diagram of a conventional distributed control system.

FIG. 8 is an explanatory diagram showing a communication procedure when data is downloaded from one AP of the FCS to a specific IOM by request-type access of the system of the conventional distributed control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ICS 2 Control bus 3 FCS 4 I / O bus 5 IOM 6 Field bus 7 Field device 8 Upper station request receiving unit AP1, AP2, ... APn application 9 Driver 10 Requested access receiving unit 11 IOM access I / F processing unit 12 Requested Separate processing unit 13 Periodic processing unit 14 Resource management unit by request 15 Resource management unit by line

Claims (7)

[Claims] A field control station communicating with the information command station via a control bus; an I / O module communicating with the field control station via an I / O bus; one of the plurality of applications; In a distributed control system including a driver unit provided in the field control station for connecting a line between I / O modules and executing data communication between the two, the driver unit includes a connection request from the plurality of applications. A data communication device comprising: information and means for managing the line use state information. 2. The data processing apparatus according to claim 1, wherein the driver requests a connection request from another application when data communication between the one application and the I / O module ends based on the connection request information and the line use state information. Exists, the line connection is maintained, the data communication between the other application and the I / O module is continued, and if there is no connection request application to wait when the data communication is completed, 2. The data communication apparatus according to claim 1, wherein the processing for disconnecting the line connection is executed. 3. The line use state information is constituted by table means indicating transition states of line not in use, line connection wait, connection confirmation wait, line connection, line disconnection wait, disconnection confirmation wait. 3. The data communication device according to any one of claims 1 and 2. 4. The communication apparatus according to claim 1, wherein the connection request information is incremented each time a connection request from the application is generated, and is decremented each time data communication of the application using the line is completed.
3. The data communication device according to any one of claims 1 and 2. 5. A connection request from another application when data communication between one application and the I / O module ends based on the connection request information and the line use state information. If there is a data communication, apparent line disconnection information is returned to the application for which data communication has been completed, and data communication processing between the other application and the I / O module while maintaining the line connection state. Continue,
5. A process for disconnecting a line connection between the I / O modules when there is no connection request application to be standby when the data communication is completed.
The data communication device according to any one of the above. 6. The data communication device according to claim 1, wherein said I / O module has a function of identifying a plurality of applications in said field control station. 7. A line connection between said driver means and said I / O module is a plurality of channels.
The data communication device according to any one of the above.