JPS6285527A - Transmission control system - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency of each communication by providing an identifier into a signal frame to decide the transmitting method of an answer between a main transmitting circuit and plural secondary receiving circuits to perform the communication. CONSTITUTION:A signal frame is sent to a signal line 2 from a primary transmitting circuit 1 in accordance with the constitution of the descending signal frame and received by the secondary receiving circuits 3-5. When it is confirmed that the addresses are coincident with the discriminating information on the circuits 3-5, these information are fetched and processed at a processing part 11. While the circuits 3-5 set the answer transmission control signals 12-14 under a state where the transmission is impossible for the answer expressed by the signal of level '0' as soon as the signal frame is received. At the same time, these signals 12-14 are set under a state where the answer can be transmitted by the state of the identifier for the answer transmitting method. Then the signals 12-14 are turned into the pulse signals that decide the level '1' or the timing to decide no answer transmitting timing according to '0' or '1' of the identifier. The secondary transmitting circuits 8-10 transmit the signal frames according to the constitution of the ascending signal frame via a signal line 7 and according to the signals 12-14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transmission control system in communication between multiple points having a master-slave relationship.

(Prior Art) FIG. 5 shows a configuration example of a communication system having a master-slave relationship based on multi-drop connections. 1 is the main transmitting circuit, 2 is the signal line, 3 is the sub receiving circuit 1.4 is the sub receiving circuit 2.5 is the other sub receiving circuit, 6 is the main receiving circuit, 7 is the signal line, 8 is the sub transmitting circuit 1 .9 is a sub-transmission circuit 2; 10 is another sub-transmission circuit; and 11 is a processing circuit. In this configuration example, signal transmission is performed in the following order. The main transmitter circuit of 1 transmits the signal frame to the signal line of 2. , the signal frame includes identification information (hereinafter referred to as address) of the destination sub-receiving circuit. Each of the sub-receiving circuits 3, 4 and 5 receives the address portion of the signal frame all at once, and if the address matches the address given to the sub-receiving circuit, all the signal frames are taken in.

If they do not match, the signal frame is discarded within the corresponding slave receiving circuit. The main receiving circuit 6 waits for reception after the main transmitting circuit 1 transmits the signal frame, and is ready to receive the signal on the signal line 7. 8, 9 and 1
Among the slave transmitting circuits 0, those that received the previous signal frame perform processing such as control according to the contents of the signal frame in the processing circuit 11, and then transmit the signal frame as a response onto the signal line 7. . Otherwise, the transmission drive circuit is inactive and does not interfere with the transmission of the signal frame. Communication is performed with the main transmitting circuit, the sub-receiving circuit, the sub-transmitting circuit, and the main receiving circuit as described above.

(Problems to be Solved by the Invention) Conventionally, in communication between multiple points in a master-slave relationship with the mechanism shown in Fig. 5, signals are sent and received after establishing a transmission control procedure between the two master-slave points ( For example, by using the HDLC master/slave station master/slave mode or the hauling selective method, a circuit that becomes a slave station can be created by attaching an address to a signal frame from a circuit that will become a master station and responding to the signal frame without using complicated transmission control procedures. In the former, full-duplex mode communication is possible, and the transmission efficiency is high on both the master and slave sides, but when the number of circuits that become slave stations increases, establishing procedures becomes an overhead and the slave station is frequently used. The disadvantage is that transmission efficiency decreases when communicating by changing the transmission medium.On the other hand, the latter does not require procedures such as establishing a transmission procedure, but considering that the response times of the slave station circuits vary, it is difficult to use the transmission medium as the master station. It is necessary to perform half-duplex communication to avoid collision of signal frames from circuits serving as slave stations in response to signal frames from other circuits, which has the disadvantage that transmission efficiency cannot be improved in individual communications. In either case, the master and slave circuits are required to have equivalent performance, so the circuits that will be the slave station should be connected to each other (or should be of a frequency commensurate with the frequency), and the processing capacity for signal transmission and reception of the circuit that will be the master station will be increased and the overall performance will be improved. It is unsuitable for systems that aim to increase communication capacity efficiently.In addition, as a technology for efficiently communicating between multiple points, communication methods using buses such as those found in LAN (
For example, there are networks that use C3MA), but the transmitting and receiving circuits in these are more complex than multi-drop circuit connections, and depending on the communication purpose, the circuit size and reliability may be 2.
It may not be suitable in terms of circuit price.

The present invention is capable of sufficiently increasing transmission efficiency using conventional technology when a circuit serving as a master station and a circuit serving as a slave station share a transmission medium and are connected in a multi-drop type in communication between multiple points in a master-slave relationship. The purpose is to eliminate the drawback of not being able to

(Means for Solving the Problems) The feature of the present invention for achieving the stated purpose is that it is composed of one main receiving circuit and a plurality of slave transmitting circuits that share a transmission medium and are connected in a multi-drop configuration. In a master/slave station type communication system, the identifier of a receiving circuit that receives a signal and a signal frame are received as a response to the signal frame, and the signal frame is transmitted when the next signal frame is received, or A transmission buffer capable of continuously transmitting signals to a plurality of sub-receiving circuits using a signal frame having a response generation method controller that supports transmitting a response signal frame at the time when it is created. A main transmission circuit that has a main transmitter circuit, a reception buffer that can store multiple signal frames, and a response control circuit that generates a response generation control signal based on the identifier of the response generation method.3 circuits that can store multiple signal frames and respond The main transmitting circuit is configured by a mechanism consisting of a secondary signal transmitting circuit that transmits one signal frame in the transmitting buffer triggered by an emission control signal, and a main receiving circuit that has a receiving buffer that continuously receives multiple signal frames. The transmission control method is such that the slave transmitting circuit dynamically changes the response signal transmission method for each signal frame based on the response generation method identifier of the signal frame transmitted by the signal frame.

(Operation) The present invention introduces a response method identifier into the signal frame,
In response to the signal frame from the main transmission circuit, the slave transmission circuit transmits a response signal frame by efficiently using the shared transmission medium according to the instructions of the received signal frame.

(Embodiment) FIG. 1 shows an embodiment of the present invention, in which 1 is the main transmitting circuit, 2
is a signal line, 3 is a sub-receiving circuit 1, 4 is a sub-receiving circuit 2.5 is another sub-receiving circuit, 6 is a main receiving circuit, 7 is a signal line, 8
9 is a slave transmitting circuit 1, 9 is a slave transmitting circuit 2, 10 is another slave transmitting circuit, 11 is a processing circuit, and 12, 13 and 14 are response generation control signals.

FIG. 2 shows 2 and 7 in the embodiment of the present invention (FIG. 1).
An example of the configuration of a signal frame used on a signal line,
The downstream signal frame flowing through 2 consists of the receiving circuit identifier (destination address), information, an identifier of the response issuing method, and frame configuration signals (frame signal, error detection signal, etc.), and the upstream signal frame flowing through 3 consists of the receiving circuit identifier(
It consists of a source address), information, an identifier for the response issuing method, and frame configuration signals (frame I, signal, error detection signal, etc.). The identifier of the response issuing method is 11 Q II
Indicates that a signal frame for response may be transmitted at any timing after receiving a signal frame, and I
IIP+ indicates that at the same time as a signal frame is received, only one signal frame for a response prepared in advance in the transmitting circuit may be transmitted.

In other words, 111 II also indicates that the processing result of the received signal frame should not be transmitted immediately after processing as a response.

FIG. 3 shows that in the embodiment of the present invention (FIG. 1) two
This shows the state of the signal frame flowing on the signal lines 7 and 7. The blocks above each line indicate frames, and the alphabetic characters within the blocks indicate destination and source addresses.

Further, the number indicates the status of the response issuing method identifier. The kana characters shown on the block are for distinguishing the correspondence between frames.

This embodiment operates as follows.

A signal frame according to the configuration of the downlink signal frame shown in FIG. 2 is transmitted from the main transmitting circuit 1 to the signal line 2. Fl of the signal frame contains information indicating the beginning of the frame, the destination address contains identification information of the sub-receiving circuit to be received, the information part contains the data to be transmitted, F2 contains the method of transmitting the signal frame for response, and Information indicating the end of the frame is set in F3. The signal frame is received by all the sub-receiving circuits 3, 4, and 5. After the 6-axis receiving circuit confirms that the received signal frame has been received normally, the destination address is determined by the sub-receiving circuit. It is confirmed whether the identification information matches the identification information of , and if it matches, the information is fetched and processed in the processing section 11.

In addition, all the sub-receiving circuits are set in advance to a state in which all response generation control signals 12, 13 and 14 cannot be generated at the same time as the signal frame is received. In the secondary receiving circuit that matches the destination of the signal frame, the response control signal of the secondary receiving circuit is set to a state in which a response can be issued, depending on the state of the response issuing method identifier in the signal frame. When the response generation method identifier is 11011, the response control signal becomes a level 1 signal that does not specify the response generation timing, and when the response generation method identifier is LL I II, it becomes a pulse signal that determines the response generation timing. . In accordance with the response control signals 12, 13 and 14, the slave transmitting circuits 8, 9 and 10 transmit Iho frames according to the configuration of the upstream signal frame shown in FIG. 2 via the signal line 7. The manner in which signal frames are transmitted and received will be explained below with reference to FIG.

Fig. 3 shows that signal frames are sequentially sent from the main transmitter circuit 1 to the down signal line 2 in a sequence of ``Irohanihohetochi'', and a signal frame as a response is transmitted via the upstream signal line 7. 】Skewer 20 High Nihohe'' and 6 main receiving circuits are receiving signals. 3 sub-receiving circuits 1 and 8
The address of the secondary transmitting circuit 2 of No. 4 is A, the address of the secondary receiving circuit 2 of No. 4 and the secondary transmitting circuit 2 of No. 9 is B, and the address of the other secondary receiving circuits, secondary receiving circuits, and secondary transmitting circuits is C.

(1) “A” signal frame is at address 11 A II
.

The response issuing method LL I II is specified, and as soon as the secondary receiving circuit 1 receives the signal frame, it transmits the signal frame umbrella 1 for the response that was in the transmission buffer to the upstream signal line. The address "A" in the signal frame indicates that the signal frame was sent from the slave transmission circuit 1, and the response issuing method 111 It indicates that the response issuing method is it 1 in receiving the signal frame related to the signal frame transmission.
Indicates that it was specified as to.

(2) The signal frame of "mouth" is similarly received by the slave receiving circuit 2, and the signal frames of 11 and 21F are transmitted to the downstream signal line of 7. Frame ``I+'' on the signal line of 2
, the signal frame for the response corresponding to the 'LL mouth' is set in the transmission buffers of the sub-transmission circuit 1 and the sub-transmission circuit 2 after being processed by each processing section (11).

(3) The signal frame "C" is for a pair of slave receiving circuits 24", and the response generation method is designated as "Ott's arbitrary timing". Immediately upon receiving the signal frame, the slave receiving circuit 2 transmits the frame 7 corresponding to the already received signal frame 1' stored in the slave transmitting circuit 2.
Transmit to the signal line.

Next, when a signal frame 1 is created in response to the signal frame ``c'', the signal frame is transmitted.Since the main transmitter circuit 1 transmitted the frame ``c'' with the response generation method set to 110 II, The next signal frame is not transmitted until the main receiving circuit 6 receives a signal frame for response corresponding to the signal frame Pach''.

(4) The "second" signal frame is transmitted to the secondary receiving circuit 1 under the same conditions as the "c" signal frame, and correspondingly, the signal frame "c" is transmitted under the same conditions as the signal frame "c". Signal frame for response from slave transmitter circuit ``in, u
2″ is sent.

(5) The signal frame "E" is for another slave receiving circuit, and the response generation method is set to "1".In this case, the transmission frame is stored in the transmission buffer in the slave transmitting circuit corresponding to the slave receiving circuit. is not set, the signal frame is not transmitted on the signal line 7. After the signal frame for the response is created, it waits for transmission in the transmission buffer of the slave transmission circuit.

(6) The signal frame “8” is for the secondary receiving circuit 1, and the response generation method is set to “1”.The signal frame for the response has already been sent to the signal frame “2”. Therefore, there is no signal frame to be transmitted in the slave transmitting circuit 1, and therefore, no signal frame is transmitted to the upstream signal line 7.

(7) For the “G” signal frame, a response signal frame corresponding to the received “H” signal frame”
” is sent.

(8) For the signal frame “chi”, a signal frame for response corresponding to the received signal frame “p”
” is sent to.

FIG. 4 shows a configuration example of the 3°4 and 5 sub receiving circuits, the 8, 9 and 10 sub transmitting circuits, and the response control signal line shown in the embodiment of the present invention (Fig. 1). is a signal line, 12 is a response generation control line, 15 is a signal frame reception buffer, 1
6 is a frame reception determination circuit; 17 is a response generation control circuit;
18 is a transmission buffer, 19 is a transmission timing circuit, 20
21 is a transmission timing control circuit, and 21 is a transmission buffer drive circuit. Signal 1 is an address signal, Signal 2 is a signal frame reception completion signal, Signal 3 is a frame reception determination signal, Signal 4 is a response method identification signal, Signal 5 is a reception signal, Signal 6 is a response generation control signal, Signal 7 is a transmission request The timing chart shows the signals, signal 8 is a transmission timing signal, signal 9 is a transmission control signal, signal 10 is a transmission buffer drive signal, and signal 11 is a transmission data signal. This configuration example operates for the following purposes.

When the input of the signal to the signal frame reception buffer 15 through the downstream signal line 2 is completed, the destination address is sent to the signal ]- and one pulse is sent to the signal 2. The signals 1 and 2 are evaluated by 16 reception determination circuits, and when it is determined that the addresses match, one pulse is sent to the signal 3. 17
The response generation control circuit has the level II I TT of the signal 4.
Alternatively, the response method identification signal of 110 II, the signal 2, and the signal 3 are input.

In the response generation control circuit No. 17, the signal 2 or the signal 4
The response generation control signal of signal 6 is reset using the falling edge of the signal. At the rising edge of signal 3, signal 6 is set and output as a response generation control signal.

The signal 3 is also input to the receiving buffer 15, and is used as a trigger for fetching the received frame into the processing section. When the transmission buffer 18 completes the setting of the transmission data signal signal 11, it sends a pulse to the transmission request signal signal 7, and requests the transmission timing circuit 19 to generate a timing pulse. The transmission timing circuit 19 continuously generates timing at the rising edge of the transmission request signal, and supplies this signal as the transmission timing signal of the signal 8 to the transmission timing control circuit 20. The transmission timing circuit 19 is released at the rising point of the transmission control signal signal 9.

In the transmission timing control circuit 20, the response generation control signal 6 and the signal 8 51! The product is multiplied and the transmission control signal of signal 9 is sent to the transmission buffer drive circuit 21. 2
The transmission buffer drive circuit No. 1 supplies a transmission buffer drive signal to the No. 18 transmission buffers using the rising edge of the transmission control signal as a trigger, and the transmission buffer converts the signal in the transmission buffer No. 7 by the transmission buffer drive signal. Transmit to the downlink signal line.

With such a configuration, even if signal frames are continuously transmitted from the main transmission circuit in the communication system 11 connected in a multi-drop type with a master-slave relationship,
Communication can be performed efficiently without collision of signal frames for responses transmitted from each slave transmitting circuit.

Preferably, in order to prevent the signal frame transmitted by the slave transmitter circuit from colliding with the signal frame transmitted by another slave transmitter circuit on the transmission medium, the signal frame transmitted by the main transmitter circuit is the same as the signal frame transmitted by the slave transmitter circuit. Therefore, the length is longer than the transmission delay.

(Explanation of Effects) As explained above, in this configuration, communication is performed between the main transmitting circuit and the plurality of sub-receiving circuits by providing an identifier that determines the method of issuing a response in the signal frame, which provides the following advantages. There is.

(a) Collision of signal frames for responses does not occur even in multi-drop type connections.

(b) By transmitting signal frames to a plurality of sub-receiving circuits, the effect of multiple use of signal lines can be maximized.

(c) The load on the secondary receiving circuits can be reduced by transmitting signal frames to a plurality of secondary receiving circuits.

(d) Since the structure of the secondary receiving circuit is simple, the circuit scale can be reduced in a communication system having many secondary receiving circuits and secondary transmitting circuits.

(e) By changing the response issuing method, it is possible to select half-duplex or full-duplex communication, and it is possible to transmit a signal frame according to the reception state of the response.

Therefore, the present invention requires a large amount of unordered information to be transferred to multiple devices at high speed using a simple interface.1 For example, rewriting line setting data of a synchronous multiplex converter from a control device. It can be applied to

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an example of the configuration of a signal frame used on signal lines 2 and 7 in FIG. 1, and FIG. Fig. 4 is a configuration example and operation time chart of the sub-receiving circuit, sub-transmitting circuit, and response control signal line shown in Fig. 1, and Fig. 5 is a conventional multi-drop connection. 1 is a configuration diagram of a communication system having a master-slave relationship. DESCRIPTION OF SYMBOLS 1... Main transmitting circuit, 2... Signal line, 3... Sub-receiving circuit 1.4... Quantity I8 circuit 2, 5... Other sub-receiving circuits, 6... Main receiving Circuit 2.7... (line i,
8...Sub transmission circuit 1.9...Sub transmission circuit 2, 10...
・Other slave transmitter circuits. 11... Processing circuit, 12.13 and 14... Response issuing control signal, 15... Signal frame reception buffer,
■6... Frame reception determination circuit, 17... Response generation control circuit, 18... Transmission buffer, 19... Transmission timing circuit, 20... Transmission timing control, 21
...Transmission buffer drive circuit signal 1...Address signal, No. 43 2...Signal frame reception completion signal, signal 3.
...Frame reception determination signal, Signal 4...Response method identification signal, Signal 5...Reception signal, Signal 6...Response issue control signal, Signal 7...Transmission request signal, Signal 8...Transmission Timing signal, signal 9... Transmission control signal, signal 10
...Transmission buffer drive signal, signal 11...Transmission data signal.

Claims (1)

[Claims] In a master-slave station type communication system consisting of one main receiving circuit and a plurality of slave transmitting circuits connected in a multi-drop manner sharing a transmission medium, an identifier of a receiving circuit that receives a signal. and supports receiving a signal frame and transmitting a signal frame as a response corresponding to the signal frame when the next signal frame is received, or at the time when a signal frame for response is created. A main transmitting circuit that has a transmitting buffer that can continuously transmit signals to multiple sub-receiving circuits using a signal frame that has a controller for how to issue a response, a receiving buffer that can store multiple signal frames, and a response. A sub-receiving circuit has a response control circuit that generates a response generation control signal based on the identifier of the generation method, and a secondary reception circuit that can store a plurality of signal frames and transmits one signal frame in the transmission buffer using the response generation control signal as a trigger. The main receiving circuit includes a secondary signal transmitting circuit and a receiving buffer that continuously receives a plurality of signal frames, and the main receiving circuit receives a plurality of signal frames according to each signal frame according to an identifier of a method of issuing a response to the signal frame transmitted by the main transmitting circuit. A transmission control method characterized by a transmitter circuit dynamically changing the method of transmitting response signals.