JPS62111546A - Serial number managing system of decentralized type loop transmission system - Google Patents

Abstract

PURPOSE:To prevent mis-discrimination of duplicated reception and to attain accurate reception by making differ a serial number of a transmission data at rising of equipment from a serial number of a succeeding data. CONSTITUTION:A count means managing a serial number is provided respectively to transmission controllers 10-13 and in raising each equipment, zero is set to each count means. Thus, zero is set to a serial number 303 of a transmission data 300. IN sending the data 300 next, the serial number is read from the count means and 1 is added to the number and the result is set again to the count means. Then whether or not the said serial number is a maximum serial number is discriminated. When the serial number 303 is maximum, 1 is set to the count means to send the data 300.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a serial number management method for a distributed loop transmission system, and in particular, to a transmission control method for a distributed loop transmission system of a transmission control type that determines double incoming calls based on serial numbers. This invention relates to a serial number management method that is effective in preventing erroneous judgments when starting up a device.

[Background of the invention]

In this type of distributed loop transmission system, multiple stations are each connected to a loop-shaped transmission path (hereinafter referred to as a loop transmission path) via a transmission control device, and the transmission data transmitted on the loop transmission path is The transmission control device that took in the data was configured to monitor the serial number in the transmitted data and determine whether there was a duplicate call.

According to such a distributed loop transmission system, the transmission control device determines double incoming calls by comparing the serial number in the previously received and imported transmission data with the serial number in the currently received and imported transmission data. This was done based on the fact that these did not match. However, as described above, since the transmission control device has determined whether there is a double call, when the transmission control device is started up, the serial number in the transmission data is
There is a problem in that if the serial number matches the serial number in the transmission data that was sent the previous time, the determination of double incoming call may be mistaken.

[Purpose of the invention]

The object of the present invention is to provide a distributed loop that always accurately determines double call arrival by preventing false calls that occur when starting up a transmission control device in systems where double call reception is determined based on serial numbers. The object of the present invention is to provide a serial number management method for a transmission system.

[Summary of the invention]

The present invention achieves the above-mentioned purpose by making the serial number at startup different from the serial number of subsequent transmission data in order to prevent the serial number from matching the serial number of the previously received transmission data when starting up the transmission control device. This is what we tried to achieve.

According to the present invention, since the serial number is sent only at startup, there will be no false determination of double incoming calls.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 4 is a block diagram showing a distributed loop transmission system to which an embodiment of the serial number management method according to the present invention is applied.

In FIG. 4, each transmission control device 10 to.

13 are connected by a loop transmission path 30, and each transmission control device 10 to 13 is connected to a station 20.
The stations 20 to 23 are connected to each other, and the exchange of transmission data between the stations 20 to 23 is controlled by each transmission control device 10 to 13.

The operation of the distributed loop transmission system configured as described above will be explained below with reference to FIGS. 1 to 3.

FIG. 3 is an explanatory diagram showing the format of transmission data transmitted on a loop transmission path. To briefly explain the format of transmission data using this diagram, transmission data 300 transmitted from the transmission control devices 10 to 13 on the transmission path 30 is divided into synchronization data 301 and allocated for each data source transmission device. It consists of a source address 302, a serial number 303 for determining double incoming calls, and transmission information 304.

Loop transmission will be performed using the transmission data 300 having such a configuration.

FIG. 2 is a flow chart shown to explain the operation for determining the arrival of received data.

Here, an example will be described in which the transmission control device 10 receives transmission data 300 from the transmission control device 12.

Upon receiving the transmission data 300 sent from the transmission control device 12, the transmission control device 10 immediately
The serial number 303' in the received transmission data 300' sent from 2 and the serial number 3 in the transmission data 300 received this time.
03 (step 200). Here 1 serial number 3
When 03 and 303' match, the received data is processed as double received data (step 201).
). However, in step 200, if the serial number 303 and the serial number 303' are different, it is determined that the data is unreceived, and the unreceived data is processed (step 202).
).

In the above, although it was explained as an example, each transmission control device 1
0 to 13 act similarly.

FIGS. 1(T) and (II) are diagrams shown for explaining an embodiment of the serial number management method.

Here, it is assumed that each of the transmission control devices 10 to 13 is provided with a counting means such as a counter for managing serial numbers.

First, when starting up the transmission devices 10 to 13, it is assumed that the counting means is set to zero. As a result, the serial number 303 of the transmission data 300 is set to zero (step 100). The cold state is the part indicated by rt On in FIG. 1 (II).

Next, when the transmission data 300 is sent out, the serial number from the counting means is read out, 1 is added to it, and the serial number is set in the counting means again (step 101).

As a result, the serial number 303 of the transmission data 300 is .

It will no longer be ``0''.

Then, it is determined whether the current serial number is the maximum serial number (step 102). This is done depending on whether the value of the counting means matches the maximum value. If it is not the maximum in step 102, the process returns to step 101 without performing any processing. By repeating these steps, the serial number 303 changes to a larger value one by one, as shown in FIG. 1 (II).

In step 102, if the serial number 303 becomes the maximum, the process moves to step 103, where the counting means receives y I
II is set and processing for sending out the transmission data 300 is performed (step 103). This step 102, 103
As shown in Figure 1 (II), "maximum serial number" → 11
This means that we took 117 routes. Then, when the process returns to step 101 again, the serial number 303 is incremented by LL 1 and l from the H2II portion of FIG. 1 (II).

In this way, according to the present embodiment, the communication control devices 10 to 1
3, a corresponding serial number is sent out, which eliminates the possibility of erroneously determining double reception.

〔Effect of the invention〕

As described above, according to the present invention, since the serial number at the start of transmission is set to a specific number, there is an effect that accurate reception can be performed without erroneously determining double reception.

[Brief explanation of drawings]

1 (I) and (II) are explanatory diagrams showing an embodiment of the present invention, FIG. 2 is a flowchart shown to explain the incoming call determination operation, and FIG. 3 is an explanatory diagram showing the format of transmission data, FIG. 4 is a block diagram showing a distributed loop transmission system for realizing the same embodiment. Figure 1 (Eno (M)

Claims (1)

[Claims] 1. A distributed loop transmission system in which multiple stations are connected to a loop-shaped transmission line via transmission control devices that control data transmission, and double incoming calls are determined by monitoring serial numbers in transmitted data. A serial number management method for a distributed loop transmission system, characterized in that a specific serial number can be set when transmission is started by the transmission control device.