JPS63227146A - Transmission block number control system in polling system - Google Patents

Abstract

PURPOSE:To attain a control which can inquire whether a transmission from a terminal equipment exists in a prescribed segment or not, by suspending the transmission at the time when a continuous transmission block number reaches a prescribed value, and executing a control so as to execute the transmission to the terminal equipment which has suspended the transmission, after a transmission processing of once is brought to a reception processing. CONSTITUTION:In a branching line connecting plural terminal equipments, as for a transmission which exceeds the number of blocks of a continuous transmission of once, which is regulated at every line, a terminal controller suspends its transmission. After this suspension, the transmission processing or the reception processing of at least once is executed to all terminal equipments including the terminal equipment which has suspended the transmission, thereafter, a control is executed so as to execute the transmission to the terminal equipment which has suspended the transmission. Accordingly, at every prescribed breakpoint, polling can be executed, and such an inconvenience as an emergency transmission cannot be executed readily due to long continuous blocks is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the number of transmission blocks in a polling method, and particularly to a method for controlling the number of transmission blocks in a polling method when transmitting blocks are continuously transmitted from a control device.

[Conventional technology]

Conventionally, as shown in the system configuration shown in Figure 2, in a line in which multiple terminal devices are connected to a control device such as a computer or terminal control device in a separate manner, the control device sequentially sends transmission requests to the terminal devices. Transmission control methods that adjust the presence/absence are often used.

This method is generally referred to as a polling method, and for example, a terminal device number is specified and a time is made, and if there is a transmission request, data is transmitted, and if there is no transmission request, an EOT (end of transmission) is transmitted. There is.

[Problem that the invention seeks to solve]

However, in the conventional polling method described above, priority is given to data transmission from the control device to the terminal device, and when this transmission request disappears, the control device inquires of the terminal device as to whether there is a transmission request. Therefore, if data transmission requests are issued continuously from the control device, it becomes impossible to make inquiries to the terminal device, and data transmission from the terminal device to the control device becomes impossible.

The purpose of the present invention is to
The control device divides the number of consecutive transmission blocks to be transmitted to this line into a predetermined fixed number, and controls the number of transmission blocks using a polling method that can determine whether or not there is transmission from the terminal device at the division interval. The goal is to provide a method.

[Means for solving problems]

The transmission block number control method in the polling method of the present invention counts the number of consecutive transmission blocks from the control device in transmission control of a control device in which a plurality of terminal devices are connected via a branch line. Transmission is interrupted when the number of consecutive transmission blocks specified for the line is reached,
After this interruption, transmission processing is performed at least once for all terminal devices including the terminal device that interrupted the transmission, and then the transmission is performed to the terminal device that interrupted the transmission. be done.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, showing a case where the terminal control device shown in FIG. 2 communicates with a plurality of terminal devices via one branch line.

FIG. 1 is composed of an I10 selection processing section 1, a termination processing section 2, a data transmission processing section 3, and a data reception processing section 4.

Tables 1 and 2 are a line control table provided in the storage device in the terminal control device and a device control table provided corresponding to the line.

Table 1 Table 2 Figures 3, 4 and 5 are I10 of Figure 1, respectively.
Selection processing unit 1. Data transmission processing unit 2. 3, 4 and 5 below, and using the field names in Tables 1 and 2,
The operation of the diagram will be explained.

First, in the I10 selection processing unit 1, it is determined whether there is data to be transmitted for one terminal device (UCB) (step 2), and if there is data to be transmitted, the L of that line is
The CBC is compared with the value of the UCB and the UCBA (step ■). Therefore, if the values of LCBC and UCBA are equal, it means that the previous transmission is the next transmission request in which the number of blocks has reached the specified value due to continuous transmission.
Steps ■ and ■ have been checked for all UCBs compatible with this line, and 72: Check (step ■)
. Here steps ■ and ■ are unchecked
If there is an eB, specify the next UCB and return to step (2) (step (2)). By the way, if there is no data to be transmitted in step (2), the process advances to the data reception processing section 4. If UCBA is different from the value of LCj3C (normally LCBA is 101) at step (1), the process proceeds to data transmission processing section 3. In addition, if the LICB check completes in step ■, check whether the jisebu is finished or not.
), if the process has been completed, the process proceeds to the completion processing section 2; if not, the process proceeds to the data reception processing section 4.

Next, in the data reception processing section 3, when the 5 UCB is specified and a transmission request is given in step I10 selection processing section 1, first, the transmission data in the storage device is selected (step 2). , then transmits l blocks (step ■), and adds 1 to LCBB (step ■). Next, the value of LCBB and the value of LCBAO are compared to check whether the number of consecutive transmission blocks has reached the specified value of the number of transmissions (step 2). The value of LCBB is LCB
If it is smaller than the value of A, check whether the next transmitted block is the final transmission block (step [phase]), and if it is the final block, perform EOT transmission processing (step ■).
. Next, compare the values of LCBA and LCBB to check whether the EOT transmission process is the one following the last block. If the value of LCBA is larger, then L
The value of CBB is set to "0" (step @), and one series of data transmission processing is completed.By the way, in step ■, LCBA and L
If the values are equal to CBB, it is assumed that the number of consecutive transmission blocks has reached the specified value, and the UC of the UCB that transmitted the LCBC value.
Record it in BA (step ■) and proceed to step ■. Also, if step @ is not the last sending block, step ■
Return to and continue transmitting the next transmission block. Furthermore, if the values of LCBA and LCBB are equal in step (2), it means that the transmission has already been interrupted seven times from step (2) to step (2), so the one-delay data transmission process is immediately terminated.

Next, in the data reception processing unit 4, in step 1 of the selection processing unit 1, if there is no transmission request for one UCB, and even if there is a transmission request for that UCH, the number of consecutive transmission blocks has reached the specified value. When it is started after steps ■, ■, and ■, in either case, first
Set the value of BA to "0°' (step [phase]). This usually means that from step (2), it is already UCBA for this UCB.

The value is '0゛°, but from step ■, LeB
Since the value of C has been entered, it is a temporary item that enables the next transmission. Next, normal block reception processing, that is, UCBK polling, is performed, and if necessary, processing is performed to have the block transmitted and received by the control device (step [Yes]).
, return to I10 selection processing section.

〔Effect of the invention〕

As explained above, according to the present invention, in a branch line connecting a plurality of terminal devices, the number of consecutive transmission blocks is defined for each line, and transmissions exceeding this number of blocks are sent to the plurality of terminal devices. Since the next transmission block can be transmitted after polling is performed at least once, it is possible to eliminate the problem of long transmission blocks from the control device preventing terminal devices from transmitting, especially emergency transmissions. effective.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a system configuration diagram to which the present invention is applied, FIG. 3 is a flowchart of I10 selection processing, which is a component of the present invention, and FIG. FIG. 5 is a flowchart of block transmission processing, which is a component of the invention. FIG. 5 is a flowchart of block reception processing, which is a component of the invention. 1... I10 selection processing section, 2... Termination processing section, 3... Data transmission processing section, 4...
...Data reception processing unit. fi3 figure 4 times 5000

Claims (1)

[Claims] In transmission control of a control device that connects multiple terminal devices via a branch line, when the number of consecutive transmission blocks from the control device is counted and this count reaches the number of consecutive transmission blocks specified for line support. After interrupting the transmission, performing at least one transmission process or reception process on all terminal devices including the terminal device that interrupted the transmission, and then transmitting to the terminal device that interrupted the transmission. A transmission block number control method in a polling method characterized by the following.