JPS59158152A - Polling control system - Google Patents

Abstract

PURPOSE:To design a communication controller with good processing efficiency by delaying the transmission of a polling sequence according to the number of consumer station equipments in polling operation and controlling the equipment to prevent the overload. CONSTITUTION:A coomand sent from a central processor is written in a section C in an area 141 corresponding to a corresponding communication circuit number in a channel correspondence memory 13. If the command indicates polling at this time, a microprogram checks a counter 21, and when its value is 0, a delay inhibition bit E in an area of the channel correspondence memory 13 corresponding to a communication circuit is set to ''1'' to advance the contents of the counter 21. Every time the polling command is sent out, the counter increases in its contents and then decreases the contents by one when the polling sequence transmission is completed. Thus, the number of other circuits in polling operation is grasped and a delay time corresponding to the number of circuits is found by using a delay time table 18 provided in a control memory 16 and set in a delay circuit 27 to adjust the transmission time of the polling sequence, preventing overload.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention provides a method for connecting a plurality of data home devices to each other by communication times mk.
This reduces the load related to communication control on the communication control device, which connects via the network and queries each data home device for the presence or absence of transferable information (hereinafter referred to as polling), and then transfers data. Regarding technology for

(2) Prior art and problems Figure 1 is a block diagram for explaining data transfer by polling method, in which 1 is a central processing unit, 2 is a communication control unit, and sl- and -sn are line support units. , <1 to 4n represent communication lines, and 51 to 5n represent data home devices. - Fig. 2 is a diagram showing the time relationship of signals on each communication line in the conventional polling method, where 61 to 6n are the timings for issuing ball commands, 71 to 7n are the polling sequence, and 81 to 8n are the read commands. Issuance timings 91 to 9n represent transfer data.

In FIG. 1, when the central processing unit 1 is instructed by a bird ball command to poll a data home device (for example, a data home device 51), the communication control device 2 performs communication via the line support unit 51. A polling sequence (a fixed format signal sequence for polling) is sent to the line 41. At this time, the data home device 51 transfers
If f-event exists, the data is sent to the communication line 41. The communication control device 2 converts the data (binary serial data) into characters, and the central processing unit 1 stores this in the storage device with a read command. When the data home device 51 receives a polling sequence, if there is no data to be transferred, communication must be terminated.

T signal).

As shown in Figure 2, when ball commands are sent to each communication line one after another, in the conventional control system, the communication control device simultaneously sends out a polling sequence to each communication line, and Since data from the devices must be processed in parallel, the processing time for each line overlaps, temporarily placing an excessive load on the communication control device. Therefore, the communication control device has the disadvantage that it must have a large processing capacity in order to withstand the load. In addition, in a device designed to execute other processes other than communication control, there is a drawback that other processes may become stagnant during the overload state.

(3) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional technology, the present invention provides a method for controlling polling that does not cause overload even when poll commands are issued intensively, and thus designs a communication control device that has high processing efficiency. The purpose is to provide a method.

(4) Structure and object of the invention According to the present invention, as described in the claims, data is transferred after polling a plurality of data home devices each connected via a communication line. In the communication control device that performs
A means for monitoring the number of communication lines that are currently performing processing related to polling is provided, and when an opportunity for polling occurs, the number of communication lines that are currently performing processing related to polling is determined by the means, and the value thereof is determined. This is achieved by a polling control method that is characterized by adjusting the start time of polling for the next data home device according to the time.

(5) Embodiment of the invention FIG. 6 is a block diagram illustrating an embodiment of the invention, in which 10 is a central processing unit, 11 is a storage device, 12 is a communication control device, 15 is a channel corresponding memory, 141 ~14n
and 151-1 sn is the area corresponding to the communication line, 1
6 is a control memory, 17 is a microprogram load area, 18 is a delay time table, 19 is a processing register, 20 is a trap register, 21 is a counter, 22 is a scan control register, 23 is a step circuit, 24 is a line number register, 25 is a receiving character buffer, 26 is a transmitting character buffer, and 27 is a delay circuit. Channel correspondence memory Areas 141 to Ian or 151 to 15n corresponding to communication lines of 15 yen are displayed as follows: 1 to n are communication line numbers, A is a data address, B is a byte count, and C
is the command, D is the transmitted/received data, and E is the position of the delay prohibition bit. Further, A', B', and C' displayed in the processing register 19 are the same as AX BX C, and t represents a communication line number.

In FIG. 5, a command sent from the central processing unit 10 is written in a 14% section C of the channel corresponding memory 15 corresponding to the corresponding communication line number (for example, No. 1). At this time, the address on the storage device it of the transmitted and received data is folded into A, and the data length of the transmitted and received data is folded into B. The data in the areas 141 to 14n corresponding to each communication line omitted in this way is read out to the processing register 19 in a time-sharing manner, an interrupt code is created based on the contents, and the data is stored in the trap register 20. is set, thereby passing processing to the microprogram.

At that time, if the command is a poll, the microprogram checks the counter 21 and if the value is 0,
The area corresponding to the communication line in the channel corresponding memory 15 (
For example, set the delay prohibition pin (151) E to 11" and increment the counter 21. When the aforementioned microprogram reads the counter 21, if the value is 0, the delay prohibition pin) E is set to XX1". The counter 21 is simply incremented. With this operation, counter 2
1 holds the number of communication lines to which ball commands were issued at the same time.

On the other hand, the data to be sent to the communication line as a polling sequence is read from the storage device 11 and written to the section of the area corresponding to each communication line in the channel corresponding memory 15, and then sent to the 100-character buffer 26. is sent to the communication line via. At this time, if the delay prohibition bit E of the area is 91'', the data is directly sent to the character buffer 2.
6 and send it, but if the delay prohibition pin is set to E
When is CN, the delay time table 18 in the control memory 16 is referred to, and the counter 21 at that time is
A delay time corresponding to the value of is set in the delay circuit 27,
Delays the time it takes to set the data to the send character path. Since there is no need to delay the transmission of the second and subsequent characters of the polling sequence data, the delay prohibition bit E is set to XX1'' when the transmission of the first character is completed.

When the sending of the polling sequence data to the communication line is completed, the corresponding delay prohibition bit is set to 10'' and the value of the counter 21 is decremented by 1.

The scan control register 22, step circuit 25, rotation number register 24, etc. in FIG. 5 share the processing related to scanning of each communication line during the above operation. Control is passed between the two.

As explained above, in this embodiment, by providing the counter 21 which increments each time a ball command is issued and which decrement the value by 1 when the polling sequence is completed, the counter 21 is provided so that when polling is performed, the counter The number of lines is determined, the delay time corresponding to the number of lines is determined from the delay time table 18 provided in the control memory 16, and this is set in the delay circuit 27 to adjust the polling sequence issuing time. This prevents overload.

FIG. 4 is a diagram showing the time relationship of signals on each communication line in the embodiment, 6'1 to 6'n17'1 to 7'n
18'l~a'n, q'1~9In are 61 in Figure 2
~6n171~7n181~8n191~9n! ', to is the time from when the ball command is issued until the polling sequence is sent, and tl-tn is the delay time given by the method of the present invention.

As shown in Figure 4, even if the ball commands are issued one after another, the data transmission of the polling sequence to the Tanimitoshi line is delayed, so the data transfer process is not completed at the same time. There is no overlap and the load is balanced.

(6) Effects of the Invention According to the polling control method according to the present invention, in a communication control device that transfers data by a polling method to a plurality of data home devices each connected via a communication line, the data can be transferred at the same time. Even if ball commands are issued intensively to each data home device, the sending of the polling sequence is delayed according to the number of data home devices that are executing polling, and control is performed to prevent overload. The effect is great because it is possible to perform efficient processing using a low-cost communication control device. In addition, the communication control device is designed to perform other processes in addition to communication control, so it is effective because it eliminates the effect of other processes being stuck due to the intensive issuance of t1 polling commands. is big.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining data transfer by the polling method, FIG. 2 is a diagram showing the time relationship of signals on each communication line in the conventional polling method, and FIG. 3 is a diagram showing one embodiment of the present invention. A block diagram to be described, FIG. 4, shows the time/quantity relationship of signals on each communication line for the embodiment. 1... Central processing unit, 2... Communication control device, 31-
3n...Line support department, 41-4n...Communication recollection, 5
1~5n...Data delivery device, 61~6fi, 6'l
~6'n...pole command issuance timing, 71
~7n, 7'l~7K,,・Polling sequence,
Bl, 81 N''~8'n... Read command issuing timing, 91~9i, 9'l~9'n...
- Transfer data, 10...Central processing unit, 11...Storage device, 12...Communication control device, 15...Channel compatible memory, 141-14n, 151-15n...Corresponding to communication line Area, 16... Control memory, 17... Microprogram load area, 1 day...
Delay time table, 19...Processing register, 20...
・Trap register, 21... Counter, 22...
Front control register, 23... Step circuit, 24... Line number register, 25... Reception character buffer, 26...
...Transmission character buffer, 27...Delay circuit

Claims (1)

[Claims] A communication control device that polls multiple data home devices connected via communication lines and then transfers data, monitors the number of communication lines that are performing all polling-related processes in parallel. A means is provided, and when an opportunity for polling occurs, the number of communication lines currently undergoing processing related to polling is determined by the means, and the start time of polling for the next data home device is adjusted according to that value. A polling control method featuring: