JPS5933953A - Communication control system in communication network system - Google Patents

Abstract

PURPOSE:To improve the performance of a decentralized system and to simplify the constitution, by including information designating a node returning a transmission confirming response to a broadcast message and returning a transmission confirming message from one of nodes receiving the transmission message to the transmission node. CONSTITUTION:A broadcast transmitting station 1, a representative station 5, and plural stations 11-14 are connected to a transmission loop 10 of a communication network system. The transmission message 8 is transmitted simultaneously from the station 1 of the system to other stations 5, 11-14 and the transmission confirming response message 9 acknowledge the receiving of the message 8 is returned from the station 5 to the station 1. The station 1 is provided with a message transmission program 2, a transmission managing table 3, and a transmission request cue 4, and the station 5 is provided with a message receiving response program 6 and a response managing table 7. Further, the performance of the decentralized system is improved with a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication control method that can efficiently confirm the delivery of simultaneous data transmission in a communication network system, and particularly to a communication control method that can be applied to a microcomputer distributed system and a real-time process control system. .

In a communication network system, if you try to confirm the delivery of data during a broadcast using responses from all the nodes, the procedure is complicated and the overhead is large, so it is better not to confirm the delivery of the data sent simultaneously. This is the current situation. As a result, the reception status is not known at all, and not only is it necessary to retransmit the current data, but it is also unclear whether the next data will be sent or not, and even the timing of the transmission.
It has the disadvantage that it cannot be applied to systems that require real-time performance and reliability, such as process control systems.

An object of the present invention is to provide a communication control system that allows confirmation of delivery of broadcast data according to the degree of necessity.

” In order to achieve such an objective, the present invention provides the above-mentioned information specifying a node that returns a transmission acknowledgment when a broadcast message is transmitted from a specific node to at least some other nodes. - The feature is that the delivery confirmation response message is included in the broadcast message and based on this information, only one of the nodes that received the message sends the delivery confirmation response message back to the sending node.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.
7 Explain.

FIG. 1 shows a system configuration of an embodiment of a communication network system according to the present invention. Computers called stations 1, 5.11-14 are connected by a transmission loop 10, and stations 1, 5.11-14 are connected by a transmission loop 10.
14 is exchanged using messages 8 and 9. In response to the transmission message 8 that transmits data, a delivery confirmation response (
Hereinafter, it will be referred to as ACK. ) Message 9 is returned from the receiving station to the sending station. The data can be sent to any station (referred to as the broadcast source station).

) 1 can also simultaneously send outgoing messages 8 to other stations 5.11-14. In this embodiment, explanation will be given on the assumption that only the representative station j (=5) returns an ACK message 9 for reception confirmation in response to the -broadcast message 8. The station 1 has a message sending program 2, a sending management table 3, and a sending request queue 4 for sending messages.

Station 5°11 for receiving/replying messages.
14 have a message reception response program 6 and a response management table 7. Generally, each station 1,5.1
1 to 14 have both transmitting and receiving functions. That is, although it has all of the message sending program 2, sending management table 3, sending request queue 4, message receiving response program 6, and response management table 7, only a simple model is shown in FIG.

FIG. 2 is an example of the message format of the transmitted message 8. The transmitted message 8 includes a destination address 81, which is the address of the station to which the message is to be transmitted;
It has a transmission source address 82 which is the address of the station that is the transmission source of the message, a transmission message serial number 83 which is used as an identification number of the transmission message, and transmission data 84 which is the transmission content. Addresses 81.82 do not need to match the station's physical address. for example,
It does not matter if the destination address 81 addresses multiple stations. In particular, in this embodiment, when the destination address 81 is equal to the source address 82, it is assumed that the transmitted message 8 is a broadcast message addressed to all stations other than the source station.

FIG. 83 is an example of the format of the ACK message 9. The ACK message 9 consists of a destination address 91 which is the address of the station to which the response is to be returned, a response message serial number 92 which indicates which message the reception confirmation response is for, and ACK data 93 which indicates that it is a confirmation response.

FIG. 4 is a configuration diagram of an example of the transmission request queue 4. As shown in FIG. The transmission data 84 is assembled into a transmission message format, has a transmission request queue chain pointer 41 attached to its head, and is connected to the transmission request queue 4 as transmission request control blocks 42 to 44. The address of the transmission control block 42 at the head of the transmission request queue 4 is set to the transmission request queue head address 31 of the transmission management table 3. The address of the subsequent transmission control block 43 is set in the transmission request queue chain pointer 41. It is assumed that the transmission request queue chain pointer 45 of the last transmission control block 44 in the queue is zero. Send request queue head address 31
When is O, the queue is empty. When a transmission request is taken in, the transmission control block 42 at the head of the transmission request queue is removed, and the transmission control block 43 becomes the head.

FIG. 5 is a configuration diagram of an example of the transmission management table 3.

The transmission management table 3 contains the above-mentioned transmission request queue head address 31 and the serial number (80) of the transmission message currently being processed for transmission.
A serial number counter 32 stores the serial number (used as a message identification number), a monitoring timer 33 monitors the time until an acknowledgment is returned, and an ACK message 9 with the same serial number as the transmitted message does not return within a specified time. At the same time, there is a transmission failure recording area 34 for keeping an error log, and - the total number of stations for which broadcast transmission is to be performed and the total number of stations of the own station, - a broadcast transmission group that is set for each station group capable of broadcast transmission. Station number table 35
(In this embodiment, -broadcast transmission is limited to transmission to all stations on the loop, so the number is the total number of stations.)
It consists of

FIG. 6 is a configuration diagram of an example of the (confirmation) response management table 7. The response management table 7 includes the representative station number 1 which stores the in-group relative number of the representative station derived from the received (sent) message serial number 83, the above-mentioned simultaneous transmission group station number table 72, and -the simultaneous transmission group ( - consists of a station number table 73 within a broadcast group, which is a table of values for each group of the relative station number of its own station within the broadcast station station (consisting of a broadcast source station and a broadcast source station). As already mentioned, in this embodiment, the simultaneous transmission was limited to transmission to all stations on the loop, so 7
3 counterclockwise to all stations on the loop from 0 to n(
n: total number of stations) is sequentially added to the number of the own station.

The operation of this embodiment will be explained below. First, an overview of the operation will be explained.

FIG. 7 is a time chart of data simultaneous transmission and 80 minutes in an embodiment of the present invention. - Even if the broadcast message with serial number 1 from the broadcast source station STO is successfully received by all stations STI to ST3, the ACK message 9 is sent only from station ST1 (at this time, ST1 is designated as the representative station). ). For the broadcast message with serial number 2, only station ST2 ACKs as the representative station.
Return message 9. For serial number 3, station 8
If T3 is serial number 4, station STI ACKs
Return message 9.

FIG. 8 shows the relationship between serial numbers and representative stations for messages broadcast from station STO in a broadcast transmission group where the number of stations is n. A circle indicates the correspondence between the serial number and the representative station. Furthermore, consider a simultaneous transmission group as shown in FIG. 1. Assume that station numbers within the broadcast group are assigned from 0 to n-1 in ascending order counterclockwise, and that broadcast transmission is performed from station 1 with number i. At this time, station No. Ti of the representative station for the broadcast message sent to the serial number J14, k-1on-1
If the remainder after dividing by is r, then when i<j, j = i + r + 1...
... (1) When i>j, j = i + r
+1-n... (2).

FIG. 9 shows the control flow of the message sending program 2. FIG. 10 shows the control flow of the message reception response program 6. A detailed explanation of the operation of this embodiment will be given below using both figures.

- The message transmission program 2 of the broadcast source station 1 executes the transmission control block 4 from the head of the transmission request queue 4.
Take out 2. When the transmission request queue head address 31 is 0, the queue is empty, that is, there is no transmission request (block 101 in FIG. 9). Next, a transmission message 8 is composed and transmitted from the transmission control plotter 42. At this time, the transmission message serial number 83 is set in the oil phase counter 32. Serial number counter 3
2id is a 16-bit counter whose initial value is 0 and increases by 1 each time a new message is sent. Set the monitoring timer 33 to wait for the transmission data ACK (
Block 102 of FIG. 9).

- The broadcast message 8 is received by each station 5 11 to 14 other than the source station 1 in the broadcast group. That is, first, message 8 is received,
Depending on whether the destination address 81 is O, it is checked whether it is a broadcast message (block 201 in FIG. 10). - Set equal to the sent message sequence number 83 to confirm the receipt (block 204 in FIG. 10). If the received message is a -broadcast message, it is checked whether it should be ACKed, that is, whether the own station is the representative station or not.Block 203 in FIG.
), Maki, which is not the representative station, does not return ACK message 9. In order to check whether the station is a representative station, first, the representative station number 71 for the received message is obtained. Already in the general explanation of the operation (
7 and 8), in general, in the simultaneous transmission shown in FIG. No. 71 (block 2 in Figure 10).
02). Equation (1) already mentioned.

As is clear from (2), for the station number j in the broadcast group of the own station, the station number j−i in the group of the own station based on the source station (when j>i) or j-r +
n (when J < i) and representative station number 71
It can be determined whether or not the own station is a representative station by comparing the two (block 203 in FIG. 10). - The message sending program of station 1, which is the source of the message, is A.
Upon receiving the CK message 9 (block 10 in FIG.
3) Check whether the serial number 92 is equal to the serial number counter 32, that is, whether it is an ACK to the message sent. If so, increase the value of the serial number counter by 1 and proceed to the next Preparations are made to send the message (block 105 in FIG. 9).

If the ACK for the sent message is not received, it is ignored and times out (the monitoring timer 33 is set to 0).
Waits for an ACK message confirming receipt of the transmitted message until (Block 103 in Figure 9). If a timeout occurs, the destination address 81 and serial number 83 of the transmitted message 8 are recorded in the transmission failure recording area 34 (block 106 in Figure 9), and preparations are made to transmit the next message (block 106 in Figure 9). Block 105).

The embodiment of the present invention described above has the following effects.

(1) All you need to do is add a simple process to the receiving program to determine whether or not an acknowledgment should be made.

(2) Like loading a large number of programs at once,
When messages are sent all at once, the stations that return acknowledgments change in order, so the reception status of all stations can be known.

(3) Although the algorithm is somewhat complicated, - A dedicated serial number is provided for broadcast messages, and missed serial numbers are used as ACK data 93.
Setting it to , is also effective in improving the efficiency of recovery from transmission failures.

In addition, instead of providing a dedicated serial number for broadcast messages,
-Retransmission efficiency can be improved by recording the broadcast serial number on the transmitting side.

(4) - The broadcast transmitter can confirm delivery using the same process as when transmitting to a single station.

(5) Continuous large number of messages - In the case of simultaneous transmission, AC
By using the reception of the K message as the timing for broadcasting the next message, simple flow rate control is possible even in broadcast transmission.

In the above example, the representative station changes depending on the serial number of the transmitted message, but the representative station may be fixed to one of the relative station numbers within the group, such as the first or last station number. In that case, the first
The representative station number operation in block 2020 of Figure 0 is no longer necessary, simplifying the process.

Furthermore, if the farthest station in the group is designated as the representative station and the reception of the ACK message is set as the next simultaneous transmission timing, the transmission path will not be unnecessarily congested and moreover, a large amount of data can be transmitted with less idle time.

Further, in the above-described embodiment, a case is shown in which simultaneous delivery is performed to all stations within a group, but simultaneous delivery may be performed to some stations within a group as described below.

Simultaneous transmission to some groups is possible by setting the most significant bit of the destination address 81 to 1 and setting the group number in the LSD 4 bits.

In order to perform ACK in this case efficiently and with high reliability, the number of stations in a group is shown in the simultaneous transmission group station number table 35 in the transmission management table and the simultaneous transmission group station number table 72 in the response management table. In the simultaneous transmission group station number table 73, the relative station numbers in the counterclockwise direction within the group are shown.
Each of these three tables uses the group number as a key,
Set it. At this time, the check in block 203 of FIG. 10 as to whether the station is a representative station is performed using the in-group relative station number obtained by searching table 73 using the group number as a key. Determination as to whether the block 201 in FIG. 10 is a mass transmission destination message is made based on whether the highest order of the transmission destination address 81 is 1 or not. Also,
The destination group number is obtained from the L8D4 bit of the destination address 81.

Each node in the destination group sends an ACK on behalf of each node in turn. This makes it possible to efficiently send data to some groups at once (data can be sent after receiving an ACK. In other words, simultaneous transmissions to some groups can be performed with high reliability and efficiency. Moreover, by obtaining a representative ACK response, Since the next data transmission timing can be known, a large amount of data can be transmitted without needlessly congesting the transmission line and without having to spend a lot of free time.

As described above, according to the present invention, it is possible to confirm the delivery of simultaneous transmission data according to the degree of necessity depending on the system and the contents of the transmission data. The present invention has an effect that can be easily realized to the extent that it can be applied to microcomputer distributed systems without sacrificing accuracy.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an embodiment of a communication network system according to the present invention, FIG. 2 is a configuration diagram of an example of a transmission message format, FIG. 3 is a configuration diagram of an example of an acknowledgment message format, and FIG. 4 5 is a configuration diagram of an example of a transmission request queue, FIG. 5 is a configuration diagram of an example of a transmission management table, FIG. 6 is a configuration diagram of an example of a response management table, and FIG. 7 is a diagram of an example of a simultaneous transmission of an embodiment of the present invention. 8 is a diagram showing the relationship between representative stations and message serial numbers in an embodiment of the present invention, FIG. 9 is a flowchart of an example of a message sending program, and FIG. 10 is an example of a message receiving response program. This is a flowchart. 1... - Broadcast source station, 5... Representative station, 2... Message sending program, 3...
Transmission management table, 4... Transmission request queue, 6...
Message reception response program, 7... Response management table, 8...- Broadcast message, 9... Response message, 10... Transmission loop, 81... Destination address, 83... Transmission message Serial number, 84...Transmission data, 92...Response message serial number, 93...A
CK data, 32...Serial number counter, 7-1...Representative station number, 35...-Broadcast group number table, 73...-Broadcast 1st redundancy 2nd part 3rd lox 4 Figure Fan 5 Figure t 3 Yu 5 6 Figure χ 7I2] No. 312] No. 912] No. 10

Claims (1)

[Claims] 1. In a communication network system that communicates between a plurality of nodes, a delivery confirmation response is returned when a specific node sends a broadcast message to at least some other nodes. A communication control system characterized in that information specifying a node is added, and a delivery confirmation response message is sent back to the node that transmitted the transmission message from only one of the nodes that received the transmission message. 2. The communication control system according to claim 1, wherein a delivery confirmation response message is returned from a node determined by the serial number of the transmitted message. 3. The communication control system according to claim 1, wherein the node that returns the delivery confirmation response message is fixed in advance.