JPS60132441A - Data transmission method - Google Patents

Abstract

PURPOSE:To improve the reliability of a data transmission system by rewriting and transferring the reception confirming signal by each station that received data in the data transmission direction of a transmission network. CONSTITUTION:A station ST3 which copies first a frame rewrites the contents of a frame status FS to FS1 from FS0 and delivers it after copying the data. In the same way, the station which copied the frame rewrites and delivers the contents of the FS when sending the frame to the next station. The contents of the FS of a frame returned to a transmission state ST1 after having a circulation along a ring are equal to an FSP obtained through successive writing. Thus the station ST1 can confirm that all addressed P units of stations have copied frames respectively.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a data transmission method of a transmission network in which a plurality of 51 computers and peripheral devices are respectively connected as stations, and these stations are connected in a ring through a transmission path. In particular, the present invention relates to something suitable for data transmission in a broadcast communication mode in a high-speed multi-computer system in which each station in the transmission network holds and processes data for the entire system.

[Background of the invention]

The IEEE (Institute of
I:1 electricals add Electron
ICS Engineers) 802 standardization proposal is known. That is, as shown in FIG. 1, ST1゜8', I"2.ST3...STN
N stations L consisting of
are connected in a shape. A transmission signal sent out from any station 1 is circulated within the ring in the same direction (in the direction of the arrow shown) and returned to the transmitting station. In this way, in a network with multiple stations, each station captures a signal called a token that circulates around the ring to determine the data transmitting station. When considering the case where the STI becomes a transmitting station and transmits data, it forms a transmission signal with the frame structure shown in Figures 1 and 32 (hereinafter referred to as a frame), and sends it to the l"it downstream of the ring. Transfer to catastrophe ST2.In Fig. 2, SD (Sta-rting IJelimite
r) is a signal indicating the beginning of a token or frame,
AC (Access (:011trO1)) is a signal containing information such as priority of transmission rights, and F C (pramme).
(:o(Itrol) is a signal containing information indicating the frame format, DA (]Je 8th nationaliofl A
ddress) is the address signal of the destination station of the frame, 5A (Source Addrcss) is the address signal of the station that transmitted the frame, INFO (Inf
or+natiOn)&j: A signal containing data transmitted from a transmitting station to a receiving station, Fe2 (Frame
Check 3equellCe) is a signal containing inspection information to perform INFO signal verification, EI)
(Ending l) e I mi ter) A signal indicating the end of the frame, pS (pram
e3tatus) is located at the end of the frame and is a reception confirmation signal containing information indicating whether or not the frame has been received by the receiving station.

Further, the transmitting station is configured to transfer data to one specific station within the ring in one transmission.

It is now assumed that STI, which is the transmitting station, has transmitted a frame addressed to ST3. In this case, the destination of the station to receive is indicated by the destination address DA in the frame.

FIG. 3 shows the state in which frames transmitted in this manner are transmitted between adjacent stations. FIG. 4(a) shows the state of a frame when it is being transmitted from STI to ST2. ST
2 is the destination address DA of the frame sent by 8T1
Since ST2 is a station that does not fall under 8T3, ST2 does not capture data from the received frame and sends the frame as it is to 8T3. In this way, when the destination address DA of the transmitted frame does not match the address of the local station and the frame is sent as it is to the next station, this will be referred to as ``6 repeats'' from now on. ST3, which received the frame repeated by ST2, imports the frame data into its own station because the destination address DA matches its own address. From now on, we will refer to the frame as "copying".In this way, ST3
When the station that copied the frame sends the frame to the next station ST4, it rewrites the contents of the frame status FS from FS1 to FS2, that is, the contents indicating that the frame has been copied.

Figures 4(a) and (b) show FSL and F82 (
An example of D content (state of bit signal) is shown. In this way, when the frame passes through station 1 in the ring, it is repeated or copied and sent back to the transmitting station 5T1t. And ST1 is frame status F
It is possible to detect that the content of S is FS2 and to confirm that the destination station ST3 has received and copied the frame sent by the local station.

However, the data transmission method described above has the following drawbacks in response to the desire to transfer data of the same content to a plurality of stations.

For example, the transmitting station STI is 8T3. ...STM,...
Assume that a frame is transmitted to P stations in the STN. In this case, by first setting the contents of the destination address Dk to include the addresses of those stations, each destination station copies the frame and sequentially transfers it to the failed station. However, the contents of the frame status FS indicating that the frame has been copied are as shown in FIG. 4(b),
In other words, since the FS2L is not defined, the frame is first rewritten to the FS2 content by Nicopi Sr3, but even if there is a station that copied the frame afterwards, it remains in the STI state of 1"82. be returned.

Therefore, although the transmitting station STI can confirm that the data has been copied at any station, it cannot confirm whether the data has been copied at all desired destination stations. In other words, even if there is a station that did not copy due to some kind of failure, it cannot be confirmed, and therefore it is not possible to take measures such as retransmitting the frame or outputting an alarm, which reduces the reliability of the system. It has the disadvantage of lowering

Therefore, the transmitting station sends - station by station to multiple receiving stations,
A method of receiving an answer back for confirmation of reception is also considered, but this method has the disadvantage that the throughput of the transmission system is reduced.

[Purpose of the invention]

An object of the present invention is to provide a one-sided data transmission system in which a plurality of stations are connected in a ring shape through a transmission path, in which a transmission signal sent from one transmitting station to one or more stations is transmitted to each destination station. An object of the present invention is to provide a data transmission method that can confirm whether or not the data has been received.

[Summary of the invention]

In the present invention, each station that receives a transmission signal rewrites the reception confirmation signal in the transmission signal to indicate that the station has received the transmission signal and transfers the signal, and the transmitting station confirms the reception of the returned transmission signal. This is intended to improve the reliability of the transmission system by checking whether each desired destination station has received the data based on the content of the data.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on embodiments. Each embodiment will be explained as being applied to the transmission network shown in FIG. are basically the same.

FIGS. 5(a) to 5(d) show changes in frame transmission status in an embodiment to which the present invention is applied. Similarly to the above, Sr3. -,
It is a time chart when frames making up the same data are transmitted to a total of P stations of STM, -, and S'rNO. As shown in the figure, after copying the data, the station 8T3 that copies the frame first changes the contents of the frame status F'S to F'S as shown in FIG. 5(C).
The frame is rewritten from SO to FSI and sent to the next station ST4.

Similarly, when the station that copied the frame sends the frame to the next station, it rewrites the contents of the frame status FS and sends it out. In this way, the contents of the FS of the frame that has gone around the ring and returned to the "C1 transmitting station STI" can be referred to as the FSP that the copied station sequentially overlaps and replaces. The transmitting station STl can check whether all the P destination stations have copied the frame.

The above frame status FS is, for example, as shown in FIG. 6(a).
As shown in (d), it is formed to have a length of 8 bits. The contents of the FS when sent from the transmitting station ST1 are all bits 0'', as shown in FIG. Since there is no frame, repeat the frame and set it to 8
Send towards T3. At this time, frame status F
The contents of 8 remain as FSO as shown in FIG. 8(b). When Sr3 captures this frame, its own station corresponds to the destination station, so it copies the frame and writes the contents of the frame status FS as shown in FIG. 6(C).
It is set to FS1 in binary 1" (hereinafter written as (1) 2) and sent to 8T4. The station that lost the frame will change the frame status F875E to the value indicated by the frame status.
1" is added and sent. Therefore,
FS returned from the P-th destination station STN to the transmitting station STI
As shown in Figure 6(d), it is confirmed that the transmitting station ST1 was able to transmit data to the desired P stations because the You will be able to do so.

Regarding a preferred embodiment device to which this embodiment is applied,
This will be explained using FIG. FIG. 7 shows the block configuration of station 1 in the ring, and all stations have the same configuration.

The station that has acquired the transmitter transmits the data to the transmitter register 25).
tt. This data is converted into serial data by the shift register 22, and the switching circuit 3
3, and is transmitted as frame 11 to the downstream adjacent station. At this time, Fe8 output from the mistranslation verification signal generation circuit 29 is added to the frame 11. Also, J”S is added to the end of the frame 11, but the FS added at the transmitting station is determined by the F8 initial value setting circuit 32.
The initial value set to ((0)2 in this example) becomes FSO. This initial value FSO is taken into the shift register 23 via the signal line 16 and converted into a serial signal, and then reflected in the FS of frame 1 in the switching circuit 33. On the other hand, a frame 10 transmitted from an upstream adjacent station is input to a shift register 20, and then a detection circuit 26 detects SD and AC in the frame. Further, the contents of DA of frame 10 input to another shift register 21 via the shift register 20 are stored in the reception register 24, and the reception control circuit 27 controls the own station's address and DA.
It is determined whether the signal matches A, and if there is a match, it is stored in the reception control circuit 27. Further, the received data is detected by the erroneous detection circuit 28 to detect the Fe in the frame 10.
An error check is performed based on 2, and the result is stored in the reception control circuit 27.

The FS transmitted at the end of frame 10 is input to the reception control circuit 2 at the time it is input to the shift register 20.
A signal 14 from 7 is captured and stored in register 30 via data line 13. This register 30
The content of the FS stored in is (0)2 for station ST2.
It becomes. In the case of ST3 where the own station is the destination, the adder 31 receives the signal 1 from the C reception control circuit 27.
5, (1)2 is added to the contents of the register 30. The output of the adder 30 is outputted to the switching circuit 33 via the shift register 23, added to the end of the 7-11, and sent out. In addition,
For stations where frame 10 is not copied, the FS
The contents of ``-111'' are not changed and are sent out as they are.

Similarly, each time a subsequent station C frame is copied, the FS
When (1) 2 is added to the contents of , and STN; is sent, the contents of FS become (['l,).

In this way, the station STI that receives the frame that has gone around the ring and sent it back confirms that the FS content is (l-2) and sends it to the desired destination. All of the stations know when a frame has been copied.That is, the output 35 of the register 30 which records the frame status FS shown in FIG. This is done by comparing the number P of stations corresponding to the destination address stored in the register with a comparator 34, and outputs a delivery confirmation signal 9.The destination station copies the frame. If not, the value of F'S is not incremented at that station,
When the transmitting station STI determines the FSO value, it is smaller than P, so it can be confirmed that the delivery was incomplete.

Steps 101 to 103 in FIG. 8 show the above-mentioned procedure from frame transmission to delivery confirmation at the transmission station. As shown in the figure, if the frame delivery is complete, the transmission operation is finished; if it is incomplete, the process returns to step 101 and 7++ transmission is performed, or the process proceeds to step 104 to diagnose the transmission system 1+J1. A program is executed to search for a failed station, output an a-report signal, etc.

As described above, according to this embodiment, the content of the frame status, which is one word indicating acknowledgment of reception in the frame, is incremented by 1 corresponding to the number of received stations, and this content is sent 1d. Since we are checking with the station,
It is possible to confirm whether or not the information has been correctly delivered to the desired number of destination stations, thereby improving the reliability of the transmission system.

In addition, as a method for checking the number of receiving stations, instead of the above-mentioned embodiment, the no-frame stakes F8 configuration shown in FIGS. The same effect can be obtained by building up ``. As shown in FIG. 9(a), the frame status FS of the frame sent from the transmitting station STI has all bits "0".

When the frame is copied in ST 3, as shown in FIG.
” will be set up. From then on, every time there is a station that copied the frame, it will beep) bl Hbz +... and “1
Then, when the frame that has passed around the ring is received by the transmitting station, if there are P 1''s in the FS, it can be determined that all stations have copied the frame. 'still,? 11 If there are fewer than P ITs, then
It can be determined that delivery is incomplete.

FIG. 10 shows a block configuration diagram of a station of a preferred embodiment of the apparatus to which this embodiment is applied. In FIG. 10, the same functions and configurations as those in FIG. 7 are given the same reference numerals and explanations are omitted.
The processing will be explained. Frame status F8 is set in shift register 37 from shift register 20 via data line 13. In the station that copied the frame, N 1 IT is shifted to the contents of the shift register 37 by the signal 8 from the reception control circuit 36, and the same amount of bit configuration as shown in FIG. 9 is formed. The contents of this shift register 37 are input to the shift register 23 via the data line 16, and then sent out as a frame status FS.

At the transmitting station that has the right to transmit, the comparator 34 compares the frame status of the incoming frame with the output of the shift register 37 and the number of transmission destinations stored in the reception control circuit 36, and confirms delivery. Outputs signal 9.

The processing after confirming the delivery of the frame is the same as the flowchart shown in FIG. 8 shown in the previous embodiment.

In any of the above-mentioned embodiments, if there is a station that does not receive reception, that station cannot be detected unless the diagnostic program is used! Although they cannot be identified, by configuring the pit strings of the frame status FS as shown in FIGS. 11(a) to (d), it is possible to identify the receiving station and the failed station. That is, each bit of frame status bn l
l) I + bz 1...bN-■ to the famous station S'l'1. in the ring. ST2...The method is to allocate the frame to the STN in advance, and the station that copied the frame sets 1" to the bit that was allocated to it.The transmitting station that receives the frame that has gone around the ring , frame status F
By referring to S, it is possible to know which stations have not been able to copy arene.

〔Effect of the invention〕

As explained above, according to the present invention, a station that has become a transmitting station can confirm delivery when the transmitted signal returns after going around the ring without transmitting a special delivery confirmation signal. Since it is possible to do this, there is no loss in throughput. As a result, failure diagnosis of the transmission system can be quickly performed, which has the effect of improving reliability.

[Brief explanation of the drawing]

FIG. 1 is a network configuration diagram of a transmission system to which the present invention can be applied, FIG. 2 is a configuration diagram showing an example of the frame format of transmission (No. Figure 4 (a). Figure 3 (b) is a diagram showing the contents of the frame status of the conventional example shown in Figure 1. Figure 5 is a diagram explaining the frame transmission status of an embodiment of the present invention. Figure 5 shows the contents of the frame status of the illustrated embodiment, Figure 7 ＼ Figure 1t) x8I! Fig. 5 is a block diagram of a station block diagram of an embodiment of the apparatus to which the illustrated embodiment is applied; Fig. 8 is a flowchart showing the processing procedure of the station; FIG. 10 is a station block configuration diagram of an apparatus to which the illustrated embodiment is applied, and FIG. 11 is a frame diagram of still another embodiment of the present invention. This is a diagram showing the contents of the status. Agent Patent attorney Tatsuyuki Unuma 1M 1'2 Funeral 3 Figure 5 Figure 5 t, t2 [3tNpp, inter eo eAl 62 63 g4 6s e66qff
llFha no 1”

Claims (1)

[Claims] 1.? A transmitting station that has acquired a transmitting tank by connecting J number of stations in a ring via a transmission path and transmits a transmission signal containing data destined for one or more desired stations to the downstream. The transmission signal is transferred to an adjacent station, and each other station takes in the transmission signal once and receives it when it is addressed to its own station.When it is addressed to another station, it is sequentially forwarded to the downstream adjacent station and sent to the transmitting station. It is a data transmission method in which data is mutually sent and received between each station, and each station that has received the transmission signal receives the content of the part indicating reception determined in the transmission signal. The data transmission method is characterized in that the transmission station rewrites the transmitted signal to a content indicating that the transmitted signal is transmitted and then transmits the transmitted signal, and the transmitting station checks whether or not each desired destination station has received the transmitted signal based on the content of the returned transmission signal. 2. In the invention as set forth in claim 1, the content of the part indicating that the data has been received is data obtained by sequentially adding "1" when each receiving station receives the data. Transmission method. 3. In the invention as set forth in claim 1, the part indicating that the reception has been received is formed from a bit string corresponding to a plurality of stations coupled to the transmission path, and each station corresponds to the station when receiving it. A data transmission method characterized by rewriting the contents of bits.