JPH06131274A - Communication control system - Google Patents

Abstract

PURPOSE:To prevent the communication efficient of the communication control system from decreasing even when a processing cell which is connected to a communication line can not be accessed owing to a power break, a fault, etc. CONSTITUTION:A wait time T is counted up by one (S1) and it is decided whether or not the wait time T exceeds a timeout time Tc; when the wait time T exceeds the timeout time Tc, the wait time T is cleared to '0' and a communication abnormality frequency R(n) is counted up by one (S3 and S4). Then it is decided (S5) whether or not the communication abnormality frequency R(n) exceeds a maximum communication abnormality frequency Rc, and when the communication abnormality frequency R(n) exceeds the maximum communication abnormality frequency Rc, the data link (n) of the corresponding processing cell is logically cut off (S6). Therefore, polling to a processing cell which can not be accessed is not performed, so the communication efficiency is prevented from decreasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network communication control system, and more particularly to an FA system (Factory Automation S
and a communication control method of a cell network in the ystem).

[0002]

2. Description of the Related Art Conventionally, in a factory where a large number of numerically controlled (hereinafter referred to as "NC") machine tools are installed, a pallet for supplying workpieces (hereinafter referred to as "workpieces") to the NC machine tools is included. An FA system including a plurality of processing cells, a cell controller that controls these processing cells, and a host computer that issues a production plan in the processing cells to the cell controller is introduced.

In the cell controller, a plurality of machining programs are stored for each product, and a predetermined machining program is edited in a predetermined order to control the NC machine tool of each machining cell. When a new production plan is instructed by the host computer, the cell controller not only replaces the tools used in each processing cell based on the request for line setup change, but also the jigs according to the workpiece to be processed. Send a command to each processing cell to replace the with the pallet.
These instructions have been issued via a communication line connected between the cell controller and each processing cell called a "cell network".

[0004]

However, when a machining cell is inaccessible due to a power cut or a failure, the cell controller repeatedly polls the machining cell within a predetermined time. During this time, no commands can be issued to other processing cells. Therefore, for example, when two processing cells are connected to the cell controller via a communication line and one processing cell becomes inaccessible due to a power cut or a failure, the cell controller causes the processing cells to become inaccessible. However, since the polling is continuously performed, the communication efficiency is reduced to 1/5 or less. Therefore, if at least one processing cell connected by a communication line becomes inaccessible due to factors such as power failure or failure, there is a problem that communication efficiency is significantly reduced.

The present invention has been made in view of the above circumstances, and it is possible to reduce the communication efficiency even when the processing cell connected to the communication line is inaccessible due to a power failure or a failure. An object is to provide a communication control method to prevent.

[0006]

In order to solve the above problems, the present invention provides a communication control system for controlling data communication performed between a cell controller and at least one processing cell, wherein When a time-out occurs when polling one, the number of communication abnormalities is counted, and when the number of communication abnormalities exceeds a predetermined number, the data link of the processing cell is logically cut off. There is provided a communication control method characterized by the above.

[0007]

When a time-out occurs when polling one of the processing cells from the cell controller, the number of communication abnormalities is counted. That is, when one time-out occurs, the communication error count is incremented by one. Then, when the number of communication abnormalities exceeds a predetermined number, the data link of the corresponding processing cell is logically cut off. As a result, the cell controller does not poll the processed cells that are inaccessible due to factors such as power failure or failure, and it is possible to prevent a decrease in communication efficiency.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an outline of an FA system configured by a cell network.

In the FA system constituted by the cell network, the cell controller 10 serves as a primary station, and the processing cells 20, 30, 40, 50 serve as secondary stations to form an FA system. In addition, these processing cells 20, 30, 4
0, 50 are CNCs (Numerical Control Unit) 21, 31, 4
1, 51 and other robots and work loaders (not shown).

The cell controller 10 is connected to a node 61 of the communication line 60 in a bus type via an interface (not shown). The processing cell 20 is connected to the node 6 of the communication line 60 via an interface (not shown).
2 is connected to the bus type. Similarly, the processing cell 30,
40 and 50 are connected to nodes 63, 64 and 65 of the communication line 60 in a bus type via interfaces not shown.

In response to the production command sent from the host computer 1, the cell controller 10 sends various data such as the machining program and the number of workpieces to the machining cells 20, 30, 40 and 50 of the secondary station via a communication line. 60 for transmission.

Further, the cell controller 10 transmits various data to the processing cell of the secondary station, and at the same time transmits the operating state of the processing cell of the secondary station to the host computer 1.
That is, the cell controller 10 monitors the operating state of each of the processing cells 20, 30, 40, 50, which are the secondary stations, and when the operation is stopped or an abnormal state occurs, the host controller 1 determines the state. And the status is displayed on the display screen. Further, the cell controller 10 transmits necessary diagnostic data to the secondary station in an abnormal state, or an abnormal state cancellation program for canceling the abnormal state.

Next, the operation when the present invention is implemented in the above-mentioned structure will be described. First, the cell controller 10 sequentially polls the processed cells 20, 30, 40, 50 connected to the communication line 60 as a cell network. That is, the processing cell 20 is first polled, and then the processing cell 30 is polled, so that the processing cell having the lower node number is sequentially polled to the processing cell having the higher node number. If a response signal is transmitted from the polled machining cell, the cell controller 10 sends various data such as the machining program and the number of workpieces to the machining cell, and receives the operating state of the machining cell. .

Here, for example, when the processing cell 20 is inaccessible due to factors such as power failure or failure, the cell controller 10 polls a predetermined number of times. If no response signal is transmitted from the processing cell 20 during this polling, the cell controller 10 thereafter determines that the processing cell 20
, The data link is logically cut off and polling is not performed. Therefore, the cell controller 10 continues data communication with the processing cells 30, 40, 50 excluding the processing cell 20. For this reason, polling is not performed for the processing cell 20 that is inaccessible due to a power cut, a failure, or the like, so that the time for polling the processing cell 20 is not required, and a decrease in communication efficiency can be prevented. .

Next, the configuration of the cell controller 10 which performs the above-mentioned various processes will be described. FIG. 3 is a hardware block diagram of the cell controller 10. In the figure, the cell controller 10 is a main CPU board 101.
It is composed mainly of. The main CPU 101 is a single board on which a processor, a ROM, a RAM and the like are mounted, and controls the entire cell controller 10. Further, the following various elements are coupled to the main CPU 101 via the bus 100.

The hard disk device 103 is a dedicated interface for SCSI (Small Computer System Interface).
rface) 102 and is connected to the bus 100,
NC in addition to production planning data that determines the processing schedule
A machining program, a program number list, etc. are stored. The shared RAM 104 is composed of DRAM. INT
The (interface) 105 outputs output information such as a work arrangement list to the printer 108 via a communication line 108a such as RS232C. The I / O board 106 exchanges input / output signals with a processing cell connected to the communication line 60.

The INT (interface) 107 is a LAN
It is connected to the host computer 1 by a communication line 1a such as (Local Area Network), receives commands from the host computer 1, and transmits the operating state of the processing cell to the host computer 1. Also, INT10
7 is a node 6 to a communication line 60 as a cell network
1 is connected.

Next, the hardware for implementing the present invention will be described. FIG. 4 is a block diagram of the interface (INT107) shown in FIG. In the figure, INT 107 is a CPU (processor) 1071, R
OM1072, RAM1073, communication control circuit 1074
And a component of the communication control circuit 1075. Note that these respective elements are connected to each other by a local bus 1076, and the local bus 1076 is connected to the bus 100 of the cell controller 10.

The CPU 1071 controls the entire INT 107 according to the communication control program stored in the ROM 1072. ROM1072 has EPROM or EEP
A ROM or the like is used to store data such as the maximum number of communication failures Rc in addition to the communication control program. RAM1
An SRAM or the like is used for 073, and input / output data or various data for communication is stored. The host computer 1 shown in FIGS. 2 and 3 is connected to the communication control circuit 1074, and performs operation control for performing communication with the host computer 1. In addition, the communication control circuit 10
75 is connected to the communication line 60 shown in FIGS. 2 and 3,
Processing cells 20, 30, 40, 50 via communication line 60
Controls the input and output of data to and from.

Next, a processing procedure for implementing the communication control method of the present invention will be described. FIG. 1 is a flowchart showing a processing procedure for implementing the present invention. This flowchart shows a processing procedure in which the CPU 1071 executes the communication control program stored in the ROM 1072 of FIG. In the figure, the number following S indicates a step number. In this flowchart, the node number of the processing cell in which the timeout has occurred is "n". [S1] The waiting time T is incremented by 1. [S2] It is determined whether a timeout has occurred. That is, it is determined whether or not the waiting time T processed in step S1 exceeds the timeout time Tc. If the waiting time T exceeds the timeout time Tc (YES), the process proceeds to step S3, and if not (NO), this processing procedure is ended. [S3] The waiting time T is cleared to "0". [S4] The communication error count R (n) of the processing cell in which the time-out has occurred is incremented by one. [S5] It is determined whether the number of communication abnormalities exceeds a predetermined number. That is, it is determined whether or not the communication abnormality count R (n) processed in step S4 exceeds the maximum communication abnormality count Rc stored in the ROM 1072 of FIG. If the communication error count R (n) exceeds the maximum communication error count Rc (YE
If S), the process proceeds to step S6, and if not (NO), the process proceeds to step S7. [S6] The data link (n) of the processing cell, which has been generated when the timeout exceeds the predetermined number, is logically cut off (off).
The data link (n) of the processing cell that is logically cut off
Are automatically and logically connected after a lapse of a predetermined time. [S7] The communication error count R (n) is cleared to "0".

Therefore, by the measure of step S6, the cell controller 10 does not poll the machining cell in which the timeout has exceeded the predetermined number of times, so that the time for polling becomes unnecessary,
It is possible to prevent a decrease in communication efficiency.

Further, since the predetermined number of times, that is, the maximum number of communication abnormalities Rc is rewritably stored in the ROM 1072 of FIG. 4, in consideration of the communication efficiency of the communication line 60 as a cell network, each FA is considered. It can be optimally set according to the system.

Further, since the data link (n) of the processing cell which is logically cut off is automatically connected logically after the lapse of a predetermined time, the processing cell which is logically cut off is If it becomes accessible immediately after that, it can be logically connected without any special measures.

In the above description, the maximum number of communication abnormalities Rc as a predetermined number of times is stored in the ROM shown in FIG.
Although it is stored in the memory 1072, it may be stored in the RAM 1073 or a non-volatile memory by parameter setting.

Further, step S4 shown in FIG.
The CPU 1071 is a part of the communication control program stored in 072, but it may be executed by the main CPU board of the cell controller 10 shown in FIG.

[0026]

As described above, in the present invention, the number of communication abnormalities is counted when a time-out occurs when the cell controller polls one of the processing cells, and the communication abnormal frequency is set to a predetermined value. When the number of times is exceeded, the data link of the corresponding processing cell is logically cut off, so the cell controller polls the processing cell that is inaccessible due to power failure or failure. Since it is eliminated, the time for polling becomes unnecessary and the deterioration of communication efficiency can be prevented.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing procedure of a communication control system of the present invention.

FIG. 2 is a diagram showing an outline of an FA system configured by a cell network.

FIG. 3 is a block diagram of hardware of a cell controller.

FIG. 4 is a block diagram of an interface.

[Explanation of symbols]

 1 Host Computer 10 Cell Controller 20, 30, 40, 50 Processing Cell 107 INT (Interface) 1071 CPU (Processor) 1072 ROM 1073 RAM 1074, 1075 Communication Control Circuit

Claims (3)

[Claims] 1. A cell controller
In the communication control method that controls the data communication performed between the processing cell and at least one processing cell, if a time-out occurs when polling one of the processing cells from the cell controller, the number of communication errors is counted. The communication control method is characterized in that the data link of the processing cell is logically cut off when the number of abnormal communication exceeds a predetermined number. 2. The communication control system according to claim 1, wherein the predetermined number of times is rewritably stored in a storage means. 3. The communication control method according to claim 1, wherein the data link of the processing cell that is logically cut off is logically connected after a predetermined time has elapsed.