JPS5977739A - Loop network system of duplex system - Google Patents

Abstract

PURPOSE:To eliminate instable operation due to repetitive multiple addressing and prevent the disconnection of normal section from a monitor controller due to disappearance of multiple addressing, by making each transmission controller select a transmission line receiving at first the multiple addressing. CONSTITUTION:Each transmission signal of systems A, B is received at circuits 34, 35 in a transmission controller 2, selected by a multiplexer MPX30 and a control circuit 5, decoded by a muCOM100 via a DEM27, and a transmission data from the COM100 is transmitted respectively via an MOD26, MPX31,32 and transmission circuits 33, 36. When the multiple address from a monitor controller is received at the system A of the device 2 at first due to a failure of transmission system, this command is detected 38 and the transmission line of system A is selected by the detection of the end of command. Even if the multiple address is received again from the A system transmission line, while the A system signal exists, the selection of the system A is continued.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a dual ring network system.

[Prior art]

Figure 1 shows a configuration diagram of a dual ring network system.

In the figure, the dual ring network system has two transmission lines (A system) 3 and (B system) 4 with different transmission directions, a plurality of transmission control devices (ST) 2, and one supervisory control device (C8T).
) 1 are connected in a loop. In this system, if a failure occurs in both A and B transmission lines in the same section between STs, the two STs connected to the faulty section will each return the signal to C8T1, Perform a so-called loopback to isolate the faulty section.

to continue operation. FIG. 2 shows the signal flow when a loopback configuration is established when a failure occurs between ST3.814.

Now, as a control method when transitioning to such a loopback configuration, various methods have been considered in the past, in which the one-sai command is sent out, and each ST that receives the one-sai command transmits the two-sai command. In this method, the relay operation is canceled only when the relay command is normally returned to the receiving side transmission line which is not relayed, thereby transitioning to a loopback configuration.

However, in this method, when transmitting the command multiple times in consideration of the fact that the command disappears due to noise in the transmission line, etc., in a certain ST, the ST downstream of the C8T
The Issai command sent back from T and the Issai command sent from C8T are received, and it is unclear which command to operate according to.

It is essential to send the Sailing command multiple times to improve reliability, and if this is not possible, the ST where the Sailing command was not transmitted due to noise will be sent even though there is no abnormality in the transmission section. Otherwise, it becomes subject to control separation from C8T.

[Summary of the invention]

In the present invention, each ST
continues to select the transmission line to operate in accordance with the signal on the transmission line to which the Issai command was first transmitted, unless the reception signal on the side currently selected for reception is exhausted.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail with reference to FIG. 3 and subsequent drawings.

FIG. 3 shows a block diagram of a general ST.

Slj, Microcomputer (μCOM) 100
, modulation circuit (MOD) 26, demodulation circuit (DEMOD)
27. Detection circuit (1) that detects whether a signal is flowing in the system (outputs a high level when detected) 2
8. (DETn) 25, - new signal (μC0M100
A detection circuit (DETC^) 38 that detects (t-detects (outputs high level at the time of detection)
(DETCm) 37, receiving circuit (Rm) 34, (
Rm) 35, Transmission circuit (Tm) 33 = (Tm
) 36, multiplexer (MPX) 31 that selects the signal to be sent to the A-system transmission line, multiplexer (MPXi+) 32 that selects the signal to be sent to the B-system transmission line, A
A multiplexer (MP
XII), and DETm, DET force, DETCa,
It consists of a control circuit (LOOP CTL) 5 that controls each multiplexer by signals from DgTCm and μCOM.

In addition, the signal SR that controls MP .

In such a configuration, the signal on the A-system transmission line is RA34
, the signal on the B-system transmission line is received by the ordinary m35, and the MPX
D is selected and input by a30 and Loop CTL 5.
Decoded by μC0M100 via EM27. μC0
Transmission data from the M100 is modulated by the MOD26, passed through the MPXm 31 and MPXm32 controlled by the LoopCTL5, and sent to the respective transmission paths by the Tm33 or T136.

(The block configuration of the C8T is described in detail in the specification and drawings of, for example, Japanese Patent Application No. 102805/1983 filed by the same applicant as the present application).
Figure) shows the detailed circuit.

LoopCTL5 has a state in which the network configuration selection signal outputted from 800M100 is input to the decoder 511 to control each multiplexer, and a state in which it controls the control circuit 513 based on the command and its pattern.

In the former state, the output of the decoder 511 is passed through gates 518 to 522 to the flip-flop (F/F) 5.
23 to 527 and each select signal (SR, etc.)
Figure 3) is output. Further, when there is no significant signal from μC0M100 to decoder 511, signal N becomes high level and is selectively controlled by control circuit 513 and gate 517.

The detectors 531 to 534 each receive input DETB,
It detects the falling edge of the signal from DET, DETCm, and DETCm (Figure 3), generates a pulse, and
/Add to the trigger terminals of F523 to 527.

The following describes the operation of each ST when a failure occurs in both transmission lines between STs and STd and a -sai command is sent from C3T1 (Figure 1) to the A and B transmission lines. I will explain about it.

Now, if a certain ST receives a command sent from the A or B transmission line, the DETC or DETCB in the ST detects the command (time it) and outputs a high-level signal. (Figure 5(a)). This signal is input to Loot CTL and applied to detection 5533 or 534. The detectors 533 and 534 detect the falling edge of the signal (in FIG. 5) (time 12) and generate a pulse. This pulse is applied as a SET signal to the trigger terminal of the flip-flop 527, and latches the signal at the D input terminal at this time.

At this time, the signal at the D input terminal is DETmu or DE
Since at least one of Tm is at a high level after time t1 (in Figure 6), the result is as shown in Table 1 ("SR" in the figure indicates the state immediately before the SET signal is generated). show.).

Note that when a failure occurs, no significant signal is output from the μC0M100, so the signal N is at a high level.

The F/F 527 in Table 1 latches the signal at the input terminal as shown in Table 1 according to the SET signal.

For example, assume that the output SR of the F/F 527 is at a low level (L) and the B-system transmission path is selected. In this case, if a failure occurs in the transmission system and the C8T sends out an Issai command, and the first Issai command that reaches this ST is received from the A system, the DETC detects the Issai command and raises the level to a high level. Outputs the signal. On the other hand, DETCm has not yet detected a signal and is outputting a low level signal. In other words, in the case of 2 in Table 1, the end of the -sai command is detected by the detector 53.
4 detects and generates the SET signal, the F/
A high level (H), that is, the A-system transmission path is selected for F 527. After that, by receiving the loopback command from the B-system transmission line (1), DETm becomes high level and even if the SET signal is generated, SR remains at high level (H). (Status A6 in Table 1). Furthermore, even if the -sai command is received again from the A-system transmission line, the SR signal continues to select the A-system as long as the signal is flowing through the A-system transmission line.

With this operation, each ST can continue to select the transmission path as long as the reception signal on the side that it is currently selecting for reception does not run out. Therefore, even if the Issai command is accidentally lost (due to noise, etc.), the Issai command can be sent multiple times, so there is a risk that the normal ST will be disconnected from the control of the C8T. There is no.

FIG. 7 shows the loopback transition operation of C8T and ST when a failure occurs. When the C8T detects the occurrence of a failure, it sends a command to both transmission lines. The ST that has received the command sends the command to the second system transmission line. If the command is lost between ST+ and STQ due to noise etc., S112 and STa will be separated from the control of C8T, but C
Since 8T sends out the "save command" multiple times, there is no fault in the section itself, but in the section where the signal is accidentally cut off due to noise etc., the signal is connected and the ST connected to the section where the fault occurred.
only is in loopback state. At this time, each ST will not be uncertain about which system to connect μCOM to due to sending the Issai command multiple times, and the system that first received the Issai command will have no signal. Continue to select shi until it becomes.

〔Effect of the invention〕

According to the present invention, the Issai command from C8T is repeated to each ST.
Even if the signal is sent, each 8T selects one transmission path and does not change as long as the signal is received. This solves the instability of operation caused by repeating the Sai command, and - C' in the normal section due to the disappearance of the Sai command.
A situation in which control is not disconnected from ST can be avoided.

In this embodiment, the dual ring network system consists of one C8
Although it is composed of a C8T and a plurality of STs, one ST may have the function of a C8T. The effects of the present invention can be obtained as long as there is one device (C8T or 8T) that has the function of detecting a fault in both systems and sending a command to both systems.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of general loop type transmission systems, Figure 3 is a block diagram of 8T, and Figure 4 is LoopCT.
Block diagram of L, FIGS. 5(a) and (b) are output waveform diagrams of DETC and detectors 53'3 and 534, and FIG. 6(a)
, (b) and (C) are the signals on the transmission path, DE'
r and the output signal waveforms of the detectors 531 and 532. FIG. 7 is an explanatory diagram of the operation at the time of loopback transition. 5...Loop CTL, 25, 28-DET,
37. 38... DETC, 531-534... Detector, 5
27 Ward 1 ¥ 30 No. 10 Continued from page 1 0 Author: Masakazu Okada 5-2-1 Hitachi University Mika-cho Hitachi, Ltd. Inumika Factory 0 Author: Hiroshi Tomizawa Hitachi University Mika-cho 5 Inumika Factory, Hitachi, Ltd., 2-1 Chome Inventor: Takeshi Onuki Hitachi University, Omika Factory, 5-2-1 Mika-cho, Hitachi, Ltd.

Claims (1)

[Claims] 1. Two loop-shaped transmission lines with different transmission directions, a plurality of transmission control devices connected to the two transmission lines, and one supervisory control device or a transmission control device having a supervisory control function. If a failure occurs in both of the two transmission lines between the transmission control devices, each transmission control device relays the -sai command to the two transmission lines to establish a loopback configuration. In the network system, each of the transmission control devices RFi includes a first detection circuit that detects an Issai command corresponding to each system, and a second detection circuit that detects that a signal is flowing corresponding to each system. A signal from the first detection circuit and a signal from the second detection circuit are input to the circuit, and a signal is sent to the transmission line indicating which of the two transmission lines the command has flowed through. What is claimed is: 1. A dual ring network system comprising a storage means for storing information when it is identified that a signal is flowing, and a multiplexer for selecting a transmission path in accordance with the storage signal. 2. Claim 1 provides that the recording device is a storage means for identifying and storing the transmission path through which the first-receipt order was received as long as the signal continues to flow through the transmission path. Features a dual ring network system.