JPS5947859A - signal transmission circuit - Google Patents

Abstract

PURPOSE:To reduce the load factor of a command section and a communication channel and to circulate correctly a transmission data through the communication channel, by providing the transmission mode transmitting the data and the repeat mode transmitting the data received from the upstream station to the downstream station. CONSTITUTION:Stations A-D have the transmission mode MT transmitting data and the repeat mode MR transmitting the data received from the upstream station to the downstream station. A managing station of right of transmission, e.g., station A detects the data circulating the communication channel over once, and changes over the mode from the MR into the MT when the number of circulations reaches a prescribed value and transmits a deleted frame DL. The circulation of the frame DL through the communication channel is detected, then the station A is changed over again into the mode MR. Thus, the unnecessary data is delected after the circulation of prescribed number of times, the load factor of the command section and the communication channel is reduced and the transmission data is transmitted to each station after circulating once through the communication channel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal transmission circuit! Loop-shaped in r pieces; fl
The present invention relates to a transmission circuit suitable for 11:m communication in a single signal path.

In a data communication network, multi-drop, roots-shaped, star-shaped, etc. are used to connect multiple stations, but from the viewpoint of high-speed response and high throughput, loop-shaped is suitable. Furthermore, in order to realize n:m communication, which enables communication between any station and any other station, 11:il1 communication is expected to be widely adopted in the future, 1:0 times. It is different from the case of Dake on the communication path; it is necessary to make only one round of the communication path and make sure that it does not exist on the communication path beyond the - round, but since it is difficult to do so, this is This was one of the reasons for inhibiting the spread of m-communications. Figure 1 is a schematic diagram of loop-like communication. 1st
In the figure, five stations A-E are connected to a loop-shaped communication path 51.
The direction of data transmitted through the 61 communication path 51 connected to is, for example, J9, sea urchin A→
■3→C-+])→E-4A is constant. Also,
A transmitting end and a receiving end of each station are connected to a communication path 51.

Each station A-Ei = 1-pan transmission circuit that performs serial-to-parallel conversion of transmitted and received data and frame control, a memory that stores take, and a -f front face section on the T-grid 7 side and controls these. It goes without saying that the command section may be a random logic or a microcomputer, and may be a 1.4 system. Note that the No. 1ij transmission circuits of stations A to E are all composed of the same circuit.

In nHm communication, each station A-E uses communication path 5 from the upstream station.
There is a repeat mode in which the data received via 1 is sent to the downstream station, and a repeat mode in which each station A to E carries data to other stations.
A transmission mode for L8 is required, and these two modes can be switched as necessary.In addition, each station A to E can send data 1 to 51; (i-i 4'f'l I
This is the time when the i'j- signal has been received and it has been confirmed that there is no designated room in the transmission right signal. This i2=; (4,
i seij, 1 bow (1, noyama 1, only 1 on ij"d51
There are only /i.

An example of borrowing serial takes to be transmitted is shown in FIG.

The serial data shown in Fig. 2 tma, ■loggbl, cvelD
ataLink (hereinafter referred to as HD I, C and 1lii-
It follows the J'o1 procedure. The division of the room in the collection of data is indicated by the start flag 52 and the end flag 57.The bit pattern of both flags 52.57 is the same, and it is decided that it is "01111110".
Destination address 53 indicating the /j131i signal received following the start flag 52.
The control section 54, the information section 55, the t-type 1 workpiece γ dress 53, the control section 54, and the information tX.
J”C8(li'r) performs error check with B55.
ameCheckSequence) 56, and a termination flag 57 at the end.

There are various types of transmission right signals, and when seven consecutive "1"s following "0" (hereinafter referred to as GA pattern) are received, the seventh 1' is changed to "θ" and There is a method of setting a start flag, and a method of setting a certain pattern frame to a position where a stake < OA pattern.

In the former method of GA Bakun only, if the γ idle data between frames is "1", it may increase to "0" due to noise, so in general, following the latter frame of qf>1 Hakun ( Use GA Bakun.

The transmission right management station that generates and transmits the transmission right signal is fixed in advance to one station so that only one station exists at the same time on the communication path 51, or it is rotated sequentially, or Each time, one game is decided from among all the games A to E.

Next, the conventional No. 13 transmission circuit and the flow of transmitted frames will be explained using FIGS. 3 and 4.

FIG. 3 is a block diagram of a conventional signal transmission circuit, and FIG. 4 is a frame flowchart in the case of FIG. 3. In FIG. 1. L D Q, a serial/parallel circuit that converts serial data into parallel data, a circuit 2, a GA detection circuit 3 that detects the GA pattern of the transmission right signal, a flag detection circuit 4 that detects the start flag 52 or the end flag 57, and Take k super 41 sent to communication path 51 in repeat mode
The signal is input to the first selection circuit 14 that selects the signal. .

After being converted into parallel take data by the serial/parallel conversion circuit 2, the data is temporarily stored in the reception)/fu register 5, and then transferred to the C memory (not shown) via the parallel data bus 20. On the other hand, GA: The fact that the GA pattern has been detected by the production circuit 3 is stored in the status register 6, and the status register 6 sends the message "JI-3'22" to the transmission control circuit 9. The flag detection circuit 4 outputs -1,
It is detected that the start flag 52 or the connection flag 57 has been received, and it is stored in the state register 6. This indicates that frame transmission has started or ended. The contents of the status register 6 are reported to a command unit (not shown) via the parallel data bus 20 as necessary.

Information for controlling the transmission and reception of data from the command section is stored in the control register 7. 'The data to be sent to the communication path 51 is stored in the 1h buffer register 8 from the memory at any time. The transmission data stored in the transmission buffer register 8 is converted from parallel data to serial data by a parallel-to-serial conversion circuit 10.
CS 56 is generated. ;Also, GA Bakoon is G
A generation circuit] 2, start flag 52 and end flag 57
is generated by the flag generation circuit 13.

The transmission data TD that can be sent out to the communication path 51 in the repeat mode or transmission mode is processed by the first selection circuit 14 as a reception data filter or by the serial/parallel conversion circuit 10. FC8 generation circuit 11. One of the outputs of the second selection circuit 15, which selects one of the outputs from the flag generation circuit 12 and the GA generation circuit 13, is selected. Note that the first selection circuit 1
A transmission control circuit 9 generates a transmission, repeat-1-switching signal 26 and a transmission switching signal 27 that select the transmission signal 4 and the second selection circuit 15, respectively.

transmission 1d, repeat switching signal 26, transmission switching No. 13 27,
Signals that control the parallel-to-serial conversion circuit 10, the PC8 generation circuit 1?1411, the flag generation circuit 12, and the GA generation circuit 13 are generated by the transmission control circuit 9,
are the transmission request signal 23 in the control register 7, the repeat signal 24, and the transmission start permission signal 2 from the status register 6.
It works according to 2.

Reception data D1 Transmission data Dt is transmitted and received in synchronization with clocks CT and K from a separately provided clock generation circuit. Since there is a repeat mode in loop communication, the receiving clock and the transmitting clock need to be in the same phase, and can be set to common clocks CT and K.

Next, the 6ft-reference of the 71/-m will be explained with reference to FIG. Now, assume that the transmission right management station is station A1, and the station requesting the transmission data is station C. It is assumed that '1' is being transmitted between Frenos that are not transmitting data.

Station A switches from repeat mode to transmission mode at time t1, transmits the transmission right frame TN and GA pattern, and thereafter transmits idle data "1" Stations B to E are in repeat mode. However, when station C receives the transmission right signal, it switches to transmission mode and prepares to transmit frame FC.

The data to be transmitted has a time delay of N[, which is the sum of the time delay caused by the communication path 51 and the time delay caused by the repeat mode and driver-receiver circuit of each station. corrected,
All stations A to E can transmit and receive correctly.

Station B transmits the received data to station C in repeat mode. Since station C has a transmission request, it has received the transmission right frame TH. When the start flag 52 of the transmission right frame TN is received, the flag detection circuit 4 stores the fact that the start flag 52 has been detected in the status register 6 and reports it to the command section. The command section receives and decodes the data received from the reception buffer register 5 via the parallel data bus 20, and when it determines that the received frame has the same pattern as the transmission right frame TN, the command section sends the data to the GA detection circuit. 3 detects a GA pattern, the control register 7 switches to the transmission mode and transmits the frame FC.
The repeat signal 24 is set to a reset state. As a result, when the station CUGA detection circuit 3 detects a GA pattern, it outputs a transmission start permission signal 22 and transmits it at time t2.The repeat switching signal 26 converts the selection signal of the first selection circuit 14 into transmission data from the reception data box. The output of the second selection circuit 15 is switched to the output of the second selection circuit 15.

Since MD and E are in repeat mode, the received data RD from the communication path 51 of the upstream station is directly transmitted to the communication path 5 of the downstream station.
Send to 1. A station that matches the contents of the destination address 53 in the frame FC transmitted by station C transfers the frame FC to the command unit.

After being transmitted from station A, the transmission right frame TN goes around the communication path 51 and returns to station A again. - Since the circulated transmission right frame TN is no longer needed in n2m communication,
It is deleted by the station A that sent it.

The first method for erasing is that after the command section recognizes that the transmitted transmission right frame TN has been received, the command section immediately requests the repeat signal 24 to enter the repeat mode, and at time t3, the command section There is a method of switching the selection circuit 14 using a transmission/repeat switching signal 26 to put station A into the repeat mode.

As a second method, after the JET command unit is notified that the termination flag 57 of the transmitted transmission right frame TN has been received, the command unit requests the repeat signal 24 to enter the repeat mode; There is a way to put station A into repeat mode.

Here, according to the method of ε1'si1, the transmission right frame'
[A part of N is erased, but because it is a repeat mode, a part of it is sent (11 frames remain TR and 17 remain,
Sent to downstream station. On the other hand, according to the second method,
If the transmission data continues after the a-right frame 'rN, it will be erased at the head 1 of the transmission data due to the processing delay from frame detection in the command section to the repeat mode instruction.

FIG. 4 shows the case of the first method, at time 1. The transmission mode is 4T from to time t3, and the repeat mode Mn is from time t3 onward.

Similarly, station Cf sends it to its own JfO75 (rJ j7 fl
ya (t:f) l/- communication path 51 to FC 75
When I7 returns to the local station, the transmitted frame i'c
Erase. This erasure method includes the first and second methods, similar to the erasure of the transmission right frame TN at station A described above. FIG. 4 shows the first method. i+! A portion of the double frame FC is sent to the communication channel 51 as a transmission frame and a remaining F frame. At station C, time 1
The period from 21jt2 to time t4 is the transmission mode MT, and the period from 21jt2 to time t4 is the repeat mode Mp.

As mentioned above, 1. In both of the second methods, there is no clear distinction between frames to be erased and frames to be reheated and sent to the downstream station, and there are drawbacks as described below. Due to the endless circulation of the transmission frame 7A9F on the communication path 51 in the evening, the flag detection circuit 4 of each station A-E is activated, and the processing in the command unit increases. This prevents the original processing operations of the command unit from collapsing. 1, the load factor of the passage 1a road 51 increases. Then, until the load on the command unit due to the circulation of unnecessary data is $t, the processing by the remaining seven rooms continues indefinitely for each Luhnow tour.

As is clear from the above explanation,
For example, the load factor of the command section is high, and the load factor of Karishin Road 51 is 1
：・The drawback is that ``I am too high, and I cannot trust the correct frame.'') It was made with lead sand in the second book, and its purpose is t'1, the load factor of the communication channel between the command center and the command center can be reduced! , 7J' decided to propose a No. 1d transmission circuit that would allow transmitted data to pass through the communication channel correctly.

The features of the present invention are a transmission mode in which data is sent 1B to each station connected to the loop-shaped path 1d, and a replay mode in which data received from the upper f) It station is transmitted to the lower vk; h'). and transmit (transmit indicating q right (selected from among the above stations that manage m signal When it detects data that circulates more than one round on the above communication channel, and when the number of rounds reaches the sufficient number of rounds, it switches its own station from repeat mode to transmission mode and sends a removed frame. The present invention is characterized in that it is provided with a means for switching the local station to repeat mode again when it is detected that the removed frame has gone around the above-mentioned communication path.

The present invention will be explained in detail below using FIG. 5.

The block 11'& configuration of the signal transmission circuit according to the present invention is the third
The frame flowchart shown in FIG.
The frame flowchart shown in FIG. 5 is constructed. FIG. 5 shows a case where the transmission right management station is station A and the number of data frame transmitting stations is six stations (see FIG. 1).

When station A switches from repeat mode to transmission mode at time t1 and transmits a frame TN and GA pattern, station Ad transmits transmission right frame 1 which has passed through communication h"351 (see Figure 1). N and the transmission frame FC transmitted by station C. Upon receiving the transmission right frame TN, the command unit of station A switches station A from the transmission mode Mτ to repeat Mn, but the transmission right frame FC is Remaining 'I'
I(, circulates through the communication channel 51.

Yes, station C also sent a transmission frame FC that went around the communication path 51f.
When i receives, the command unit of the own station sets the 0 station to transmission mode, Mr.
to switch to repeat mode MR.

However, in this case, as shown in FIG. When the number of detections reaches a certain number (two times in Fig. 5), the command unit of station A detects the remaining Li' It of the transmitted I M frame. is switched to the transmission mode MT, and the idle pattern between frames is sent as a specific pattern 1a. In this ζ, the fixed number of detection times can be set arbitrarily as long as it is two or more times. Furthermore, in a signal transmission circuit that can only transmit an idle pattern after frame superstition, the removed frame DL is transmitted and then the idle pattern is transmitted. , Figure 5 shows the case where the idle pattern is continuous "1" and the removal frame DLf is certain.

Then, when station A detects the end flag 57 (see Figure 2) of the removed frame ILL that has been cycled, the command section of station A sets the repeat signal 24 via the control register 7 (gi13 figure). , transmission (iM/repeat switching signal 26 causes the first selection circuit to switch to gold, and at time t6, station A is switched from the transmission mode Mr to the beat mode Mn.

As shown in FIG. 5, after detecting the termination flag 57 of the deleted frame DL that has been cycled, even if the processing time in the command section of the A station has elapsed, even if the IT is switched to the transmission mode and the repeat mode MR is changed, only the idle pattern remains. is transmitted to the downstream station, and unnecessary data does not circulate through the communication path 51. Therefore, the load on the command unit and the communication path 4'-
can be reduced by approximately 7% each.

Although the seven frames used in the above view had the configuration shown in FIG. 2, the same effect can be obtained by using frames with other configurations. In this case, if the patterns of the start flag 52 and the end flag 57 are different, the GA pattern will also be different. Needless to say, it needs to be changed.

Further, the idle pattern may be a specific pattern of consecutive "J"s, and the -C transmission 1N may be used to remove unnecessary data, and the effect does not change depending on the pattern.

As explained above, according to the present invention, unnecessary data can be removed after being circulated a predetermined number of times, the load factor of the command unit and the communication path can be reduced, and the transmission data can be correctly routed through the communication path. This has the effect of transmitting data to each station in one round.

[Brief explanation of the drawing]

FIG. 4 is a block diagram of a conventional transmission circuit, FIG. 4 is a frame flowchart according to FIG. 3, and FIG. 5 is a frame corresponding to FIG. 4 for explaining an embodiment of the signal transmission circuit of the present invention. This is a flowchart. 3...GA detection circuit, 4...flag detection circuit, 9.
...Transmission control circuit, 12...Flag generation circuit, 13.
...GA generation circuit, 14.15... selection circuit, 21.
... Transmission photon signal, 22... Transmission start W [Tsukasa 4g-+
Ba 23. ,, Incoming call absorption signal, 24... Repeat signal, 26... Sending 11F Rihi. 1st mouth C Figure 2 Figure 30 CLK → 13 Procedural amendment (method) u (H1115-1, , 12, , 22, 1 Special, 7'1 Office Commissioner Wakasugi No. 1's husband, If f student's Displayed in 1982, 1-De;'1 Application No. 156569 Name of the invention: Signal transmission circuit corrector 1, It J's Gate" f, 'rj'l Applicant 1:
11j Tokyo Riyo III-ku Marunouchi-1115 1υ' +4 +51+ll 44 type 2+1
[1st production place fee); Name 3 Ll] Masaru
Osamu Shigeyo Hitoi 11j Riyo 111-ku Marunouchi, Tokyo ---1
115 No. 1 Stock Company 1.1: 1.1. j/, manufactured f1 -3, 'A bundle +, + old' + -4221 + Mr. Otsu (C city ()) Bu'bu 1- high
Akira Hashi - Husband Amendment AI Ordinance Date 1981 1
January 30th amendment Nozukizo The content of the addition to the brief explanation of the drawings in the specification is corrected.

Claims (1)

[Claims] 1. In a serial data signal transmission circuit in which a plurality of stations perform n:m communication via a loop-shaped communication path, each station transmits the data (il mode and receives data from an upstream station). One transmission right management station selected from among the stations that manages a transmission right signal indicating a transmission right has a repeat mode in which the transmitted data is transmitted to a downstream station, and one transmission right management station selected from among the stations has a repeat mode in which all of the plurality of stations are in the repeat mode. , the station detects data that circulates over the communication channel more than once, and when the number of cycles reaches a predetermined value, switches the own station from repeat mode to transmission mode and sends out the removed frame.1 If the removed frame is A signal transmission circuit characterized in that the signal transmission circuit is equipped with a means for switching the own station to repeat mode again when detecting that the communication path has been completed. 2. The transmission right management station arbitrarily selects one of the plurality of stations 3. The signal transmission circuit according to claim 1, wherein the removed frame is a specific pattern of idle patterns between transmission frames. A Δ transmission circuit according to item 1 or 2.