JPS6332298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling communication between a device that controls a group of terminal devices (hereinafter referred to as a terminal control device) and a terminal device (hereinafter referred to as a terminal).

Generally, when communicating between a terminal control device and a terminal, the terminal control device sends a polling command (hereinafter referred to as polling) to the terminal in order to report various states occurring in the terminal, and the terminal A method is adopted in which a response is returned according to the status of the message. That is, the terminal control device side always has the initiative to start communication. For this reason, even if something that is not in a steady state occurs on the terminal side (for example, a transmission request from the terminal, the termination of operation of the terminal, the occurrence of an abnormal state of the terminal, etc.), the situation cannot be immediately reported. This results in a wait until polling is sent from the terminal control device. By the way, when multiple terminals are connected to a terminal control device, this type of polling is performed sequentially and sequentially in a predetermined order (for example, starting with the lowest terminal number) in order to equalize the service frequency of each terminal. Sent repeatedly. This order is managed and executed by the terminal control device without being changed even if an output sequence or an input sequence is executed with a certain terminal. This is called a cyclic fixed polling method. on the other hand,
The output sequence for outputting a message from the terminal control device to the terminal is started from the terminal control device, but in this case as well, when the polling order managed by the terminal control device comes to the terminal in question, instead of polling, The output sequence is started by sending an output sequence start command.

In this manner, in the conventional cyclic fixed polling method, the polling order is fixed, so that a wait for the polling order occurs during communication between the terminal control device and the terminal. That is, one is waiting on the terminal side from the occurrence of an unsteady state at the terminal until polling is issued to the relevant terminal, and the other is the start of the output sequence from the occurrence of an output factor in the terminal control device. The terminal control device side waits until then. This waiting time for waiting for polling order increases according to the number of terminals connected to the terminal control device.
This caused a decrease in communication efficiency between the terminal control device and the terminal.

The present invention has been made in view of the above-mentioned circumstances, and is a terminal communication control method that makes it possible to improve communication efficiency by reducing the waiting time for polling order that occurs in communication between a terminal control device and a terminal. Our goal is to provide the following.

Simply put, the present invention, when a terminal control device program requests polling priority service for a certain terminal, inserts polling to the terminal at fixed intervals during normal cyclic polling, and adjusts the polling frequency of the terminal. raise. Furthermore, when a terminal control device program requests data output from a certain terminal, the cyclic polling is temporarily stopped and an output sequence to the terminal is started. In this manner, the present invention dynamically changes the polling order in response to a request from the program side, thereby reducing the waiting time for waiting for the polling order that occurs in the terminal and terminal control device. Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, particularly showing the hardware configuration of a portion of a terminal control device related to the present invention. In Figure 1, 1 is a terminal address register that holds the terminal number of the terminal currently communicating, and 2 is composed of multiple indicators provided corresponding to terminal numbers, which display whether or not a terminal with the corresponding terminal number is connected. Similarly, 3 is an output request flag register that indicates the presence or absence of a data output request to the terminal corresponding to the terminal number, and 4 similarly indicates the presence or absence of a polling priority service request to the terminal corresponding to the terminal number. This is the priority service flag register. The indicators provided for each terminal number in these polling flag registers 2, output request flag registers 3, and priority service flag registers 4 are controlled by a control circuit 7 controlled by instructions of a program in the terminal control device. It can be set or reset through. Reference numeral 5 indicates a pointer register that holds the terminal number corresponding to the currently referenced indicator in the polling flag register 2 indicators, and 6 similarly indicates the currently referenced terminal number in the output request flag register 3 and priority service flag register 4 indicators. It is a pointer register that holds the terminal number corresponding to the indicator.
These registers are updated by the microprogram controller 8 through the pointer update line 11. The terminal address register 1 is rewritten by sending the contents of the pointer register 5 or 6 through the transfer line 13 according to instructions from the microprogram controller 8. Transfer instructions are given via a transfer instruction line 12. Reference numeral 10 denotes a read line for checking whether or not indicators of the polling flag register 2, output request flag register 3, and priority service flag register 4 are set in the microprogram control device 8.

Figure 2 shows that the program of the terminal control device is polling flag register 2 and output request flag register 3.
The table also shows at what point each indicator of the priority service flag register 4 is set or reset. As shown in FIG. 2, before the terminal control device starts polling the terminal group, the program sets an indicator corresponding to the corresponding terminal number in the polling flag register 2 according to the connection state of the terminal. Also, after polling has started, when data output to a certain terminal is ready, the program sets indicators corresponding to the corresponding terminal numbers in the output request flag register 3 and priority service flag register 4, and outputs the data at the end of the output sequence. The corresponding indicator in the request flag register 3 is reset. Furthermore, if it is desired to increase the polling frequency and provide polling priority service to a specific terminal, the indicator of the corresponding terminal number in the priority service flag register 4 is set, and if it is desired to stop the priority service, it is reset.

FIG. 3 is a control flowchart of the microprogram controller 8, where TNR is the terminal address register 1,
PFR is polling flag register 2, WFR is output request flag register 3, SFR is priority service flag register 4, PR5 is pointer register 5,
PR6 corresponds to pointer register 6, respectively.
Also, pf (PR5) is the indicator in polling flag register 2 corresponding to the terminal number indicated by pointer register 5, and wf (PR6) is the indicator in output request flag register 3 corresponding to the terminal number indicated by pointer register 6. Similarly, sf (PR6) represents an indicator in the priority service flag register 4 corresponding to the terminal number indicated by the pointer register 6.

Next, the operation shown in FIG. 1 will be explained. Now, eight terminals from terminal number 0 to terminal number 7 are connected to the terminal control device, and therefore the indicators corresponding to terminal numbers 0 to 7 in polling register 2 are set to "1" by the program. Assume that it is set. In this state, first consider the case where the priority service flag register 4 and the output request flag register 3 are not set by the program.
At this time, the processing steps of the microprogram control device 8 are 14→15→16→17→18→ in FIG.
It will change like 19 → 15 → 16 → 17 → 18 → 19 → 15 →...19 → 14 →..., and this will be repeated. That is,
In this case, polling is sent out sequentially and repeatedly for terminal numbers 0 to 7.

Next, consider a case where a program requests a polling priority service to a certain terminal and sets the corresponding indicator of the priority service flag register 4 to "1". At this time, the microprogram control device 8
The processing steps are 14→20→21→ in Figure 3.
22→20→…20→23→24→25→21→22→20→…22→
The transition is as follows: 15→… That is, during cyclic polling, when the terminal number of the terminal to which the next polling should be issued becomes an even number, the presence or absence of a polling priority service request is checked, and if there is a priority request, polling is sent to that terminal, and the priority request is processed. When the polling sequence ends, cyclic polling is restarted again.

Next, consider the case where a program requests data output to a certain terminal and sets the corresponding indicators of the output request flag register 3 and priority service flag register 4 to "1". At this time, the microprogram processing steps in Figure 3 are 14→20→21→22→20.
→…20→23→24→26→21→22→20→…22→15→…
The transition is as follows. That is, like the polling priority service, when the terminal number becomes an even number, the presence or absence of an output request is checked, and if there is an output request, an output sequence to the terminal is started, and when the output sequence is completed, cyclic polling is restarted. In this case, the program resets the corresponding indicator of the output request flag register 3 when the output sequence is completed.

In Figure 3, the polling priority service and the output request service are performed in accordance with the program's request every time polling by circular polling is issued twice. This can be easily changed by providing a . Further, in the embodiment, polling control is performed using a microprogram using a microprogram control device, but it is also possible to perform polling control using hardware logic.

As explained above, according to the present invention, by dynamically changing the polling order based on a request from the program side, it is possible to reduce the waiting time for waiting for the polling order that occurs in the terminal and the terminal control device. I can do it. Therefore, the program performs cyclic polling for terminals that are not in use, provides polling priority service for terminals that are in use, and provides data output priority service for terminals that require data output. By freely controlling polling frequency and data output according to the status and type of the terminal managed by the program, the system improves communication efficiency with the terminal, shortens terminal response time and processing time, and improves system performance. This has the advantage that the overall processing capacity can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
This figure is a diagram for explaining the point in time when the indicators of each flag register in FIG. 1 are set and reset, and FIG. 3 is a flowchart for explaining the operation of FIG. 1. 1...Terminal address register, 2...Polling flag register, 3...Output request flag register, 4...Priority service flag register, 5, 6
...Pointer register, 7...Control circuit, 8...
Microprogram controller.

Claims (1)

[Scope of Claims] 1. In a terminal communication control method that controls communication between a terminal control device and a plurality of terminal devices controlled by the terminal control device, the terminal control device is configured to a first register for registering a polling order, a second register for registering a terminal device requiring priority polling, and a third register for registering a terminal device requiring data output;
and the contents of the first, second, and third registers can be rewritten by a program, and cyclic polling is performed on the plurality of terminal devices in the order indicated by the first register, and the cyclic polling The second
and the third register, and if a terminal device is registered in the second register, sends polling to the terminal device, and when it is finished, restarts the circular polling indicated in the first register. If a terminal device is registered in the third register, a data output sequence to the terminal device is started, and when the data output sequence is completed, the circular polling indicated by the first register is restarted. terminal communication control method.