JPH0568037A - Communication controller for control network - Google Patents

Abstract

PURPOSE:To provide the communication controller for the control network in which multiple address communication is implemented at a high speed with high reliability. CONSTITUTION:A communication control section 22 generates data by putting transmission sequence numbers allocated uniquely to each of slave stations together with transmission data stored in a transmission buffer 21A the number of the slave stations for objects of multiple address communication and outputs simultaneously the resulting data from a transmission reception section 25. A data reception section of each slave station receives the data and fetches only the transmission data and returns the relevant transmission sequence number relating to itself to a reception reply decoding section 23A as a reception sequence number. The reception reply decoding section 23A converts the reception sequence number into a reception end number, the transmission control section 22A collates the reception end number with the transmission sequence number, output succeeding transmission data similarly when they are matched and sends again the transmission data not received when unmatched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device for a control network, and more particularly to a communication control device capable of relatively reliable and high-speed broadcast communication.

[0002]

2. Description of the Related Art In recent years, the network structure of computers has come to have a complicated appearance as computers are online. The control networks used in factories are becoming more complex as usual. In this control network, one master station provides transmission data to each of a plurality of slave stations individually or simultaneously, and the slave station drives a control device connected to it based on the transmission data. It has become. For example,
As shown in FIG. 3, when the master station A communicates with one slave station B connected to the master station A, first, the master station A inputs the transmission data, and the slave station B is unique to the slave station B. Is added to the slave station B and is output as a signal to the slave station B. The slave station B inputs this transmitted signal, fetches only the transmission data, converts the transmission sequence number into the reception sequence number, and returns it to the master station A. The master station A collates the returned reception sequence number with the transmission sequence number added when transmitting the transmission data, and if they match, it transmits the next transmission data in the same way, and the transmission sequence number matches. If not, it retransmits the sent data. The above process is repeated until all the transmission data has been transmitted. As a result, the transmission data to be sent to one child station will be transmitted with high reliability.

[0003]

However, in such a conventional communication control device, it is possible to perform highly reliable transmission in the communication between the master station and one slave station as described above. However, there are the following problems in the broadcast communication between the master station and two or more slave stations. In the case of broadcast communication, it is not considered to assign a serial number to a slave station, so in general, as in the case of communication with a single slave station described above, the transmission sequence number for each slave station Cannot be given. Therefore, in order to perform broadcast communication by the conventional communication control device, 1. 1. Perform broadcast communication except for the function of matching transmission sequence numbers and retransmitting when there is a mismatch. 2. Confirm the delivery of the broadcast using a command dedicated to the broadcast, or 3. It depends on whether the same transmission data is repeatedly transmitted to each slave station, or the like. For this reason, when the broadcast communication is performed as in the first method, the reliability of the communication system deteriorates, and it cannot be used in an environment in which an error is induced. Further, when the broadcast communication is performed as in the second method, the delivery confirmation needs to be performed by the host, so that the process only by the communication control device is no longer necessary. Finally, if the broadcast communication is performed as in the third method, the reliability can be maintained, but since the broadcast communication is not strictly speaking, it takes a long time for the communication, and the control that requires the simultaneity is performed. Can not be used for.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a communication control device of a control network capable of relatively high reliability and high speed broadcast communication. And

[0005]

The present invention for achieving the above object provides a communication control device used in a control network and having a function of performing broadcast communication to a plurality of slave stations. When the transmission data to be communicated is input, a unique transmission sequence number assigned to each slave station is added to the transmission data in a sequence of slave stations to be broadcast-communicated. , The transmitting means for transmitting the data created by the data creating means to the slave stations to be broadcast, and the data provided by each slave station, and assigned to itself among the data sent from the sending means. Receiving means for taking out the transmission sequence number and the transmission data, converting the transmission sequence number into a reception sequence number, and taking the transmission data into its own station,
The reception sequence number from each slave station converted by the reception means is input and collated with the transmission sequence number at the time of transmission, and if they match, a transmission command for the next transmission data is output to the transmission means. If they do not match, a communication control means for outputting a retransmission command for the current transmission data is provided.

[0006]

When the transmission data to be broadcasted is input, the data creating means links the transmission order numbers unique to the respective slave stations for the slave stations to be broadcasted. Added to. The transmitting means transmits the data created by the data creating means to the slave stations to be broadcast. The receiving means is provided in each slave station, takes out the transmission order number and the transmission data assigned to itself from the data transmitted from the transmitting means, and converts the transmission order number into the reception order number. At the same time, the transmission data is taken into the own station. This allows each slave station to receive the same transmission data at the same time. The communication control means inputs the reception order numbers from the respective slave stations converted by the reception means, collates them with the transmission order numbers at the time of transmission, and if they match, transmits the next transmission data to the transmission means. A command is output, and if they do not match, a command for resending the current transmission data is output. Therefore, it becomes possible to confirm whether or not each slave station has received the predetermined transmission data, and the reliability of the broadcast communication can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration block diagram of a communication control device of a control network according to the present invention, and FIG. 2 is a schematic explanatory diagram showing communication control performed by this communication control device. As shown in FIG. 1, the communication control apparatus according to the present invention includes one master station 10 and a plurality of slave stations 3 connected thereto.
It consists of 0 and. The master station 10 is provided with the same number of data generation units 20A, 20B, ..., 20N as the connected slave stations. The data generation unit 20A includes a transmission buffer 21A for temporarily storing transmission data to be transmitted to a slave station, a transmission sequence number added to the transmission data, and output to the transmission / reception unit 25, while being output from the reception response interpretation unit 23A. The transmission control unit 22A that determines the retransmission of the transmission data according to the received completion number, and the retransmission buffer 24A that temporarily stores the data with the transmission sequence number added, which is output to the transmission / reception unit 25, for retransmission. And a reception response interpretation unit that extracts only the reception sequence number from the slave station corresponding to the data generation unit 20A from the reception sequence numbers received from the slave units by the transmission / reception unit 25 and outputs the reception sequence number to the transmission control unit 22A. 23A and 23A are provided. The other data generation units 20B, ..., 20N and the like have the same configuration as above. The transmission control unit and the reception response control unit of each of these data generation units are respectively connected to the transmission / reception unit 25 provided in the master station. Further, the parent station 10 includes slave stations 30A, 30B, ..., 30.
N are connected to each other. This slave station 30A receives the transmission data sent from the transmission / reception unit 25 to which the transmission sequence number is added and separates the transmission data and the transmission sequence number from each other by the data reception unit 31A and the data reception unit 31A. A reception response transmission unit 32A that outputs the transmission sequence number to the transmission / reception unit 25 as the reception sequence number is provided. The other slave stations 30B, ..., 30N have the same configuration as above.

The communication control device of the present invention having the above-mentioned configuration operates as follows. This operation will be described with reference to FIG. In the figure, node A of the control network is the master station, node B,
C and D are child stations. Therefore, the master station A is provided with the same number of data generating units as the slave stations, that is, three units. Since the transmission between the master station and the single slave station is exactly the same as the conventional one, the description thereof will be omitted in this embodiment, and only the broadcast communication which is a feature of the present invention will be described. ..

First, when transmission data to be broadcasted is sent from the host computer to the master station A, all the data generating units 20A, 20B, ..., 20N of the master station A input this transmission data, and Transmission buffers 21A, ..., 2
Temporarily stored in 1N. Each transmission control unit 22A,
, 22N, the transmission sequence number uniquely set for each slave station is added to this transmission data and temporarily stored in the retransmission data buffers 24A, ..., 24N, and at the same time as the stored data. Data transmission / reception unit 2
Output to 5. The transmission sequence number is used by the master station to confirm that the transmission data has been reliably transmitted to the slave station to be transmitted. The transmission / reception unit 25 combines the data output from the transmission control units 22A, ..., 22N and outputs the combined data. As shown in the figure, this combined data is the data in which the transmission order numbers for the respective slave stations are linked and then the transmission data are linked. In the figure, the case of broadcasting to B, C, and D three slave stations is illustrated. Therefore, the data is
The transmission sequence numbers of B, C, and D are linked to the transmission data.

This data is simultaneously output to the respective slave stations 30A, ...
... will receive this data. The data receiving unit 31a takes in only the transmission data of the received data and, at the same time, converts the transmission sequence number of itself into the reception sequence number and outputs it to the reception response transmission unit 32A ,. For example, in the slave station B, the transmission sequence number B is output to the reception response transmission unit 32A as the reception sequence number B. The reception response transmission unit 32A outputs the input reception sequence number to the transmission / reception unit 25. The reception response interpretation unit 23A of each data generation unit provided in the master station outputs the reception completion number based on the received reception sequence number. The transmission control units 22A, ... Collate the reception completion number with the transmission sequence number, and if they match, transmit the next transmission data to the slave station in the same manner as above. On the other hand, if they do not match, it is determined that the transmission data has not been correctly transmitted to the slave station, and the data stored in the retransmission data buffer 24A is retransmitted in the same manner as above. These processes are performed by each data generation unit 20A, .... The above processing is performed for all the transmission data, and the broadcast communication ends. The above-mentioned transmission sequence number, reception sequence number, and reception completion number are all initialized when the network is initialized. As described above, even though the transmission data is sent to a plurality of slave stations at the same time, the reception confirmation from each slave station can be surely performed. You will be able to plan.

[0011]

As described above, according to the present invention, the broadcast communication in the control network can be performed at high speed with high reliability.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a communication control device of a control network according to the present invention.

FIG. 2 is a schematic explanatory diagram showing communication control performed by the device shown in FIG.

FIG. 3 is an explanatory diagram showing conventional communication control.

[Explanation of symbols]

 10 ... Master station 20A, ..., 20N ... Data generation unit 21A ... Transmission buffer (data creation means) 22A ... Transmission control unit (data creation means, communication control means) 23A ... Reception response interpretation section (communication control means) 24A ... Retransmission Buffer (communication control means) 25 ... Transmitting / receiving section (transmitting means) 30A, ..., 30N ... Slave station 31A ... Data receiving section (receiving means) 32A ... Reception response transmitting section (receiving means)

Claims (1)

[Claims] 1. A communication control device used in a control network and having a function of performing broadcast communication to a plurality of slave stations, when the transmission data to be broadcast is input, the respective slave stations are transmitted. The data creation means for adding the unique transmission sequence number assigned to the above to the transmission data by linking only the slave stations to be broadcast, and the data created by the data creation means are broadcast. Transmitting means for transmitting to the power station and the transmission sequence number assigned to itself and the transmission data among the data transmitted from the transmitting means provided in each slave station, and transmitting the data. While converting the sequence number into the reception sequence number, the receiving means that takes in the transmission data in its own station and the receiving sequence number from each slave station converted by the receiving means It is input and collated with the transmission sequence number at the time of transmission. If they match, a transmission command for the next transmission data is output to the transmission means, and if they do not match, a retransmission command for the current transmission data is output. A communication control device for a control network, comprising: communication control means.