JPS59181845A - Loop access system - Google Patents

Abstract

PURPOSE:To attain equitable communication by transmitting a transmission continuance request signal if the transmission is not completed in a period or the right of transmission is not acquired in a loop transmission system comprising a synchronizing station and plural node stations. CONSTITUTION:The synchronizing station transmits a synchronizing signal F permitting synchronizing communication in a prescribed period T0. When the passing of synchronizing communication signal blocks B1 and B2 is finished, the synchronizing station transmits a trigger signal M permitting asynchronous communication. If the asynchronous communication signal block B3 passes on the way of passing of the signal block B4 and a communication enable time T1 comes around, a station transmitting the signal block B4 transmits the transmission continuance request signal M. Since the synchronizing station trnsmits a transmission restart signal in the next frame before the trigger signal M, the remaining signal block B4 is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an access method for a loop network to which synchronization 1 West is supplied.

As an access method for a loop network to which a synchronization signal is supplied, there is a patent application number 1983-212364 entitled "Loop Communication System." In this system, the clock station sends out a synchronization signal at a fixed cycle, so when the node station detects the passage of this fixed cycle, it ends the transmission, stops controlling the acquisition of transmission rights, and starts the next cycle. you need to wait until However, in the next cycle, the valley node station acquires the transmission right based on the trigger signal sent by the clock station, so the node station closer to the clock station has more connections to acquire the transmission right, and vice versa. The problem is that the farther away the node station is, the fewer opportunities there are.

An object of the present invention is to provide a loop network access method in which valley node stations can fairly acquire transmission rights regardless of their physical locations.

In the loop access method of the present invention, in a loop network configured of one clock station and a plurality of node stations, and in which a synchronization signal is loosely transmitted at the clock station period, the node station is If the transmission is completed after a period of 100 seconds, or if the transmission is not obtained, the transmission continuation request No. 1 is sent, and the clock station receives the request continuation signal to the above-mentioned transmission. In the second period, the node station transmits the transmission request signal, and only the node station that sent the transmission continuation request signal obtains the transmission preference based on the transmission resume signal.

Next, the present invention will be explained in detail with reference to the drawings. 1st
The figure shows the configuration of a loop network according to the present invention.

The loop 4y network in FIG. 1 consists of node station 1.
2.3.4.5.6 and a clock station 7, which are connected by a loop 8. FIG. 2 shows the signal of the loop 8 which is input to the output terminal of the node station 4 in a 7-bang block, and FIG. Figure 3(a)
1 shows the configuration of a signal block sent by the clock station 7 and the configuration of a transmission request continuation signal, and section (b) shows the configuration of a signal block for communication between node stations. In Figure 3, PR is the preamble, SF is the start flag, SY is the synchronization pid, MO, Ml are the control bits that give the communication mode, EF is the end flag, DA is the destination address, SA is the sender address, and INFO is the Indicates an information field.

The clock station 7 sends the signal F to the loop 8 at a constant period To. The synchronization signal F is shown in Figure 3(a).
o +g configuration, hit 5Y=1, bit MO: 0
.

M1=0. When each node station detects bit 5y=i, it resets its respective timer and also outputs bit MO=M1=0, and the node stations that have the right to forward synchronous communication, for example, voice communication 1g, Send a signal block. Assuming that node station 1.2 has this transmission right, the second
As shown in the figure, following the synchronization signal F, signal blocks B, , B, . . . are supplied to the loop 8. This signal block has the configuration shown in FIG. 3(b), with bit 5Y=1), bit MO.

Δ·11 is the same as [bJ period signal F, and both are 0. The clock station 7 removes the synchronizing signal F that has made one cycle from the loop 8, and also removes the synchronization signal F from the loop 8 and outputs the first block E1. B.

After passing through, it acquires the transmission 4 status and sends out a trigger signal M that starts asynchronous communication. Trigger signal M has the configuration shown in FIG. 3 (al), bit 5Y=0, bit MO=O.

rvi 1. = 1. Now, suppose that a transmission request for this first phase occurs at node station 3°.1.5. As shown in FIG. 2, following the trigger signal M, the node station 3 sends out a signal block B8, and the node station 4 sends out a signal block B4 following the signal block B3. These signal blocks have the configuration shown in FIG. 3(b) and include bits SY, Mo, 1v
It is the same as that of the trigger signal M.

Assume that in the node station 4, the transmittable time T1 in the period has elapsed while the signal block B4 is being transmitted. When the node station 4 learns that the time T1 has elapsed, it ends the transmission and sends out a transmission continuation request signal R. This request signal R has the configuration A'j'; shown in FIG. 3(a), with bits 5y=o and 7tMQ=1°Ml-0. Since the time T1 has elapsed since the node station 5 acquired the transmission 1ieI, the transmission right acquisition control for transmitting its own signal block is stopped, but in order to transmit the transmission continuation request No. ”Go continues. However, when the passage of the request signal R from the node station 4 is detected, this transmission right acquisition control also stops.

When the clock station 7 receives the request signal R from the node station 4, in the next cycle, it sends out a transmission restart signal S'If instead of the trigger signal M after the end of the communication started by the synchronization signal F. The transmission resume signal S has the configuration shown in FIG. 3(a), and SY=O.

Bit MO=M1=1. Only the node station that sent the request signal R at the cycle of the transmission restart signal 'S il''i, AiJ, in this case only the node station 4, is triggered.After the transmission restart signal S passes, the node station 4 sends out the signal block B4. .

This signal block B4 is bit ■~10-0°M1=1
Therefore, after passing through block No. 16, the node station 5 starts controlling the transmission paddle 1b1 and acquires the transmission paddle.

If node station 4's 1g ends and node station 5 takes over 1's T+, then node station 4 does not send the Yasugi signal 1e, so node station 5 When it acquires the transmission 1g right, it sends out a request signal R. In this case, the next period of asynchronous communication is started from the node station 5 based on the transmission restart signal R.

Next, valley node station and clock station 7
The operation of the loop interface section will be explained using FIGS. 4 and 5. The loop interface section of the valley node station shown in FIG. 4 has an input terminal 10 connected to the loop 8, an output terminal 11, and a buffer 12.
．． Control circuit 13゜1i5- detection circuit 14. Receive buffer 15. It consists of a timer 17 and a transmission buffer 18.

In the non-congestion state, the signal block applied to input terminal 10 is sent to buffer 12 . The signal from the switch 30 is output to the output terminal 11. The signal detection circuit 1.1 receives the preamble PR of the 16th block, the start flag SF,
Bits SY, MO, Ml.

It detects the end flag, destination address LIA, and sender address SA, resets the timer 17 by setting bit 5y=1, and notifies the control circuit 13 of other detection results. When a transmission error occurs in asynchronous communication, control circuit 1
3 stores the signal block to be transmitted in the transmission buffer 18 f
NL, also based on the detection result of the signal detection circuit 14, the end flag EF of the signal block with bits MO=0 and M1=1.
When ' is passed, the control signal 131 turns on the switch 30 to the transmission buffer 18 side, and sends out the preamble PR to the output terminal ]1. If the signal detection circuit 13 detects the preamble PR while sending out the preamble PR, that is, if the signal block from the upstream node station is supplied to the input terminal 10, the control circuit 13 stops the superstition. and returns the switch 30 to the loop 811i1. Then, the above control is repeated after waiting for the next end flag EF to exceed :1ji1.

Then, during the transmission of the preamble PR, the signal detection circuit 14
If it does not detect the preamble PR, it sends out the 1.5 right to all '4's and sends out the 16th block in the sending banonoa. If the timer 17 loses track of the elapsed time T1 while transmitting this signal block, the control circuit 3 terminates the transmission of the signal block and stores the compromise number G in the transmission buffer 18. and send it. Then, when the No. 1 calculation circuit 14 detects the end flag EF, it returns the switch 30 to the loop 8 side. Therefore, the signal block is removed by loop 8 at the originating 18 node station. If the timer 17 notifies that the time T1 has elapsed during the transmission right acquisition control described above, the control circuit 13 detects the request 1 by the signal detection circuit 14.
1VfO=1, Ml=0
When detected, transmission right acquisition control is stopped. If the request i-R does not pass, the transmission right acquisition control is transferred and the transmission 1d
When the shield is acquired, a request signal R is sent out.

The signal block is received by the control circuit 13 activating the reception buffer 15 when the destination address supplied from the signal detection port 14 matches its own address.

The clock station shown in FIG.
It is composed of a transmission buffer 28 and a switch 31.

The timer 27 sets the bit SY of the signal block in the transmission buffer 28 to 1 at the period TO, and supplies time information to the control circuit 23. The control circuit 23 uses this time information to set the bit MO of the signal block in the transmission buffer 28.
, Ml f are both set to 0, and the switch 31 is set as the synchronization signal F.
It is sent to the output section 21 via. The switch 31 is turned on by the control signal 231 prior to transmission to the transmission buffer 28 . The control circuit 23 returns the switch 31 to the loop 8 side when the signal detection circuit 24 outputs the end flag EF of the signal block of focus MO=M1=O. Therefore, the synchronization signal F is looped and removed at the clock station. The signal configuration circuit 24 beeps) MO=
When the 1°Ml-00 request signal R is detected, the control circuit 23 sets the bit MO=0, IVl1=1 when the synchronizing signal F completes one round of the loop 8 and then acquires a free signal.
Trigger + cr Pino instead of Yoshi M) MO=l, M
Retransmission of l=1 1) r1'bj''i S is input and a transmission axis is given to the node station that has input Yasugi 1-17 before the other nodes.

In Figure 4, when the signal detection circuit 14 detects passage of the transmission restart signal S, the node that has transmitted the request value +iR in a certain period switches the switch 30 to the transmission buffer 1.
811ijil turn on bottle) MO=0°Ml,=1
and import/export the signal block.

In this way, according to the present invention, even if communication between nodes is interrupted in cycle To, the communication between nodes is interrupted in the next cycle.
A node station that has been sent or a node station that has not been able to obtain a transfer message can acquire a transfer message later, and each node station is Communication can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the loop network of the present invention, FIG. 2 is a diagram showing 100 numbers on the loop, FIG. 3 is a diagram showing signal blocks used in the embodiment of the present invention, and FIG. FIG. 5 is a block diagram showing the loop interface section of the node station and clock station used in this embodiment. In the figure, 1, 2, 3, 4, 5.6 are node stations, 7 is a clock station, 8 is a loop, 12.
15, 18, 22.28 are buffers, 13.23 is a control circuit, 14.24 is a multiplier calculation circuit, 17.27 is a timer, 30, 31 are switches? Boss. ω\-A'view-J-i, isi, original TT <'”
Figure 1 Figure 8 2 Figure 3 (b) PRSF SY MOMI DA S
A INFOEF No. 1J-B 5th Ward

Claims (1)

[Claims] One clock station is composed of a plurality of node stations, and the clock station has a constant frequency a.
In a loop network that sends a synchronization signal to the loop at j, when the node station interrupts and completes transmission at a certain period or fails to acquire the right to transmit, it sends a request signal to continue transmitting, and the clock station A loop characterized in that when the transmission request continuation signal is received, a transmission resume signal is sent in the next cycle, and only the node station that sent the transmission continuation request signal acquires the transmission right based on the transmission resume signal. Access method.