JPS62146043A - Deformed u-link system - Google Patents

Abstract

PURPOSE:To obtain a data link system having high reliability by establishing a link as a U-link system to operate it without degrading the capability and the function even if a trouble occurs in a transmission medium to disconnect it. CONSTITUTION:Each node condition is detected based on preliminarily determined control, and the mode of the node is switched and controlled as shown in figures (a)-(c) in accordance with detection results. That is, the repeat mode is set when changeover switches are not operated; and when changeover switches SW1A and SW1B are turned on, the clock of a clock generator 15 and a flag signal indicating that the node itself is a clock source are outputted to an incoming transmission line 112, and the input of an incoming transmission line 111 is outputted to an outgoing transmission line 114 through the switch SW1B, and the mode of the node itself is set to the clock mode. When a switch SW2 is turned on, the output of the incoming transmission line 112 is outputted to the outgoing transmission line 114 simultaneously, and a flag signal indicating that the node itself is in the turn-back mode is outputted into a transmission data frame on the incoming transmission line 112 through a mode inserter 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a U IJ tank type, and particularly to a highly reliable modified U-link type.

[Conventional technology]

Conventionally, the method of connecting a number of nodes and transmitting data in opposite directions to a transmission medium divided into upstream and downstream nodes is to input and output data to nodes L1 to LN and to each node, as shown in Figure 8. data terminal units)E1%EN
It is made up of. A clock is generated at the node Ll, and the transmission line passes through each node of the upstream transmission line, and at the final node LN (referred to as the most upstream node), the transmission line folds back, and reaches the downlink transmission line, υ node Ll, and ends. At this time, each node supplies data from each data terminal unit to the upstream transmission line, and supplies data to each data terminal unit from the downstream transmission line.

Here, the transmission line connecting four nodes L2 and L3 is
Check the situation when disconnection occurs at connection point X3. As shown in Figure 9, the connection point is simply disconnected, but unless self-recovery is performed within the node, the upstream and downstream transmission lines will be isolated, making data transmission impossible, and all The function will stop. However, in reality, by short-circuiting the signals that are input and output from the upstream and downstream transmission lines at the node L2, a link is established only between the nodes L1 and L2, and data can be exchanged. On the other hand, nodes L3 to LN
Then, a clock is generated at node L3, and nodes L3 to LN
It is possible to input and output data between each data terminal unit (E3 to EN) through the upstream and downstream transmission lines.
A link is established.

However, in this case, the conventional links are separated and links are established within each sublink, so data cannot be input/output between the sublinks.

[Problem that the invention seeks to solve]

The problem with the conventional technology that the present invention aims to solve is that when a transmission medium fails and is disconnected, a link is established between each of the disconnected links, but the problem between each disconnected link is data is not exchanged,
Therefore, in the worst case, it may be of no use at all.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a modified link system that overcomes the above-mentioned drawbacks.

[Failure to solve the problem]

The modified U IJ tank type of the first invention of the present invention is to connect a plurality of mates in a ring to transmit data in opposite directions through a transmission medium divided into up and down, and to transmit data in the opposite directions on the clock source side. A mode that accepts upstream data from the medium and sends it to the upper 9 transmission medium on the opposite side, and accepts data from the downstream transmission medium on the opposite side to the clock source and sends it to the downstream transmission medium on the clock source side. A mode that accepts upstream data from the transmission medium on the clock source side and sends it to the transmission medium on the opposite side to the clock source and a downstream transmission medium on the clock source side and receives the clock from the clock source as upstream data. Based on predetermined rules at the node that can take either of two modes: transmitting the data to the upstream transmission medium and transmitting the upstream data received from the upstream transmission medium on the opposite side to the downstream transmission medium as downstream data. The mode includes transmitting data input to the plurality of nodes to an uplink transmission medium and outputting data received from the downlink transmission medium.

The modified U-link device according to the second aspect of the present invention has a transmission medium divided into uplink and downlink that connects a plurality of nodes in a ring and transmits data in mutually opposite directions, and an uplink transmission medium from the uplink transmission medium on the clock source side. One mode accepts data and sends it to the upstream transmission medium on the opposite side. A mode in which upstream data is accepted from an upstream transmission medium and sent to an upstream transmission medium on the opposite side of the clock source and a downstream transmission medium on the clock source side, and a mode in which the clock from the clock source is used as upstream data and sent to the upstream transmission medium. The input data is transmitted upstream by making a transition based on predetermined rules between this mode and a mode in which the upstream data received from the upstream transmission medium on the opposite side is sent directly to the downstream transmission medium as downstream data. and a plurality of the nodes for outputting data received from the downstream transmission medium to the medium.

〔Example〕

Next, the present invention will be described in detail with reference to drawings showing embodiments.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram illustrating the operation of the present invention at abnormal times, and FIG. 3 ta) to (C) are modes of the node of the present invention. FIG. 4 is an explanatory diagram showing node transition control of the present invention. FIG. 5 is a diagram showing node transition conditions of the present invention.
The figure is a diagram showing the mode transition status of the node of the present invention, and FIG. 7 is a block diagram showing the configuration of an embodiment of the node of the present invention.

An overview of embodiments of the present invention will be described.

As shown in FIG. 1, one embodiment of the present invention inputs data to an upstream transmission medium, that is, an upstream transmission line M100, a downstream transmission medium, that is, a downstream transmission line 101, and nodes N and -NN corresponding to the respective nodes. Output data terminal unit E1
~EN, upstream transmission line Zoo and downstream transmission line i1
01 is node N! ~NN are connected respectively. In such a case, the clock generator 102 of one of the nodes, eg, node N, operates and supplies a clock signal to the upstream transmission line 100. Signals on the uplink transmission line that are input at the same time are folded back as they are and output to the downlink transmission line.

Further, data output from the data terminal unit is output from each corresponding node to the uplink transmission line, and data outputted from the downlink transmission line is outputted from each node to the corresponding data terminal unit. Next, referring to FIG. 2, the situation when the transmission line is cut will be explained. For example, if the transmission line between nodes N3 and N4 is disconnected at the connection point X1, a clock is generated from node N4 and node N1
is a normal repeater, and the signal from the upstream transmission line output at node N3 is directly connected to the downstream transmission line, making it a conventional repeater.
It starts operating in the same form as +7 link. In order to perform such operations, each node detects the situation, and depending on the result, the mode of the node changes to generate a clock.

Next, the operation of the mode of the node according to the present invention will be explained.

First, three types of modes of nodes will be explained.

Looking at Figures 3(a) to (C), the common operations required are:
supplying input data to an upstream transmission medium, ie, an upstream transmission line, and supplying output data from a downstream transmission medium, ie, a transmission line. The first mode shown in FIG. 3(a) is called a repeater mode, and is connected to the clock source side (for example, connected to the node NN side with respect to the node NN shown in FIG. 1). The data received by the transmission forest (referred to as upstream data from the downstream node) is output as is to the upstream transmission line and sent to the upstream node), and the data received from the downlink transmission line (referred to as downlink data from the upstream node) is output as is. on the clock source side (for example, the first
It is output to a down transmission medium (connected to the node NN-1 side with respect to node NN shown in the figure), that is, a down transmission line (sent to a downstream node). The second mode shown in FIG. 3 [b] is called a return mode, in which upstream data from a downstream node is sent to its -1-1 upstream node, and at the same time, it is sent as downstream data to a downstream node. , downlink data from the upstream node is detected but not taken in and is interrupted at this node. Figure 3 (C
) Node 30 shown in ) is in clock mode and generates a clock from its own node, does not send upstream data to the upstream node, and returns upstream data from the downstream node and sends it to the downstream node as downstream data. It is something to do.

Furthermore, the detection contents of the ring status that each node has for transition between these modes will be explained. The first detection content is to detect the presence or absence of a clock on the uplink transmission line, and the second detection content is to detect the presence or absence of a clock on the downlink transmission line. The third detection content is the clock generation source (
The fourth detection content is to detect whether the immediately downstream node (that is, the previous node) is in loopback mode.

Next, we will show the main conditions for node transition for recovery such as transmission line disconnection. Firstly, when there is no clock on the upstream transmission line, the detected node goes into clock mode.Secondly, when there is no clock on the downlink transmission line in repeater mode, the node goes into loopback mode.Thirdly, when there is no clock on the downlink transmission line, the node goes into loopback mode. If there is a clock on the downlink transmission line during mode, the own node becomes a repeater node.Fourth, in the third case, when the immediately downstream node is in return mode, the own node becomes clock mode.Fifth, clock mode Sixthly, in the fifth case, if the node immediately downstream is in loopback mode, the own node is in clock mode &, and seventhly, clock mode In the case of , both the upstream and downstream transmission lines have clocks. If the transmission line has a clock sourced from another node, it is in beater mode. Eighth, in the seventh case, when the immediately downstream node is in loopback mode, The condition for node transition is to remain in clock mode. FIG. 5 shows a more detailed IF summary of these node transition conditions, and FIG. 4 shows the details of node transition control under these conditions. Note that the symbols IA, IB, . . . in FIGS. 4 and 5 indicate control conditions. Further, FIG. 6 shows the modes before and after the transition in this case, corresponding to each condition. The present invention can be implemented by the method described above.

Next, an example of these operations will be explained with reference to FIGS. 1 and 2.

In Figure 1, if the upstream and downstream transmission lines connecting nodes N3 and N4 are disconnected, the clock coming out of Nl will first be connected to the upstream clock transmission line at nodes N2 and N3. Even if a clock is detected, no clock is detected on the lower transmission line. Also, node N4~
In N, the upstream and downstream transmission iK clocks are not detected. Further, at node N, the clock input from the upstream transmission line is not detected. At this time, node N2-83 enters the return mode according to the IC transition conditions shown in FIG. 5, but since the operating time of the nodes generally differs,
The nine nodes that transition early will dominate the nodes that transition late.

In this case, when node N3 enters loopback mode, node N
Since the clock is detected on the upstream and downstream transmission lines, the device 2 remains in the repeater mode under the transition condition gIF in FIG. 5. However, when node N enters loopback mode, node N3 has a clock on its upstream transmission line, but there is no clock on its downstream transmission line, and node N2 immediately downstream is in loopback mode. Under the transition condition of IB in the figure, node N3 enters the return mode. Next, since the node N2 has a clock on the upstream and downstream transmission lines and the node N1 directly downstream thereof is in the clock mode, the node N2 becomes the Peter mode under the transition condition 2F in FIG.

On the other hand, in the nodes N4 to NN, since there is no clock on the upstream and downstream transmission lines, the node with the fastest transition operation under the transition condition of IA in FIG. 5 becomes the clock mode. At this time, all nodes downstream from the node that has entered the clock mode, such as node NN, remain in the repeater mode because there are clocks on the upstream and downstream transmission lines.

Next, among the nodes upstream of the node that has entered the clock mode, the node that has completed the transition operation becomes the clock mode. In this way, the operation continues downstream, and finally node N4 enters the clock mode. Therefore, a clock mode node sandwiched between repeater mode nodes has a clock on the upper 9 and downstream transmission lines, and the immediately downstream node is a repeater, so that other nodes can be detected. Therefore, 3F in Fig. 5 including node Nl
All become repeater mode depending on the transition condition.

Therefore, node N4 is in clock mode, node N3 is in loopback mode, and all other nodes are in repeater mode to complete the link as shown in FIG.

Next, an embodiment of the present invention will be described focusing on its configuration and operation.

As shown in FIG. 1, the present invention connects nodes Nl- and -NN to an upstream transmission medium, ie, a transmission line 100, which is composed of lines such as coaxial cables, and a downstream transmission medium, ie, a downstream transmission line 10.
1, and each data is transmitted from the data terminal units D1 to DN through the nodes N1 to NN to the upstream transmission line 10.
0, and data from the lower nine transmission lines 101 are supplied to corresponding nodes N1-NN through terminal units D8-DN, respectively. Each node is the 6th node in the link.
The device is constructed so as to be able to change modes as shown in the figure, and an example thereof is shown in FIG.

Next, the configuration and operation of the node will be explained.

Signals on the upstream transmission medium are input from the upstream transmission line 111 to node 1 and output to the upstream transmission line 112, signals on the downstream transmission medium are input from the downstream transmission line 113 and output to the downstream transmission line 114, and the transmission line is coaxial. Constructed with cable or double layer method. Further, data from the data terminal unit 2 is outputted to the uplink transmission line 112 through the data inserter 17, and data outputted from the downlink transmission line 113 is also supplied to the data terminal unit 2.

Next, node 1 includes clock detectors 11 and 13, node detector 12, control logic 14, and clock generator 15.
, a mode inserter 16, a data inserter 17, and changeover switches 5WIA-8WIB-8W2.

First, the clock detectors 11 and 13 detect the presence or absence of a clock on the upstream and downstream transmission lines 111 and 113, respectively, and input the results to the control logic 14, and the node detector 12 detects the clock generation node from the upstream transmission line 111. (
In other words, the detection of the clock source node) and the detection of the immediately downstream node (
It detects whether the previous node) is in loopback mode or in any other mode, and inputs the result to control logic 14.

Furthermore, the mode inserter 16 inserts a recognition RM code into the frame of transmission data when the own node is in loopback mode, and the data inserter 17 inserts the data from the data terminal unit 2 into the transmission line for upstream transmission. It is inserted into the data frame.

On the other hand, the operation of the control logic is controlled by the selector switch 5WIA-8.
Activate WIB and SW2 (turn ON)
In particular, when the selector switch is not activated, it is in repeat mode.

Next, the changeover switches 5WIA and 5WIB operate (
ON state), the clock that is the output of the clock generator 15 and the indicator signal indicating that the own node is the clock source are transmitted to the upstream transmission line 112 through the changeover switch 5WIA.
The input of the uplink transmission line 111 is the changeover switch 5.
The signal is output to the downlink transmission line 114 through the WIB, and the mode of the own node becomes the clock mode. Also, selector switch S
When W2 is activated and in the ON state, is there uplink transmission? tM
112 is simultaneously outputted to the down transmission line 114 through the changeover switch SW2, and the mode of the own node becomes loopback mode, and the indicator signal indicating that the own node is in the loopback mode is also sent to the transmission data on the uplink transmission line 112 through the mode inserter 16. Output into frame. Furthermore, here, only the indicator signal indicating that the signal to the mode inserter is in return mode is outputted into the frame of the transmission data on the uplink transmission line, but three modes may be identified and the indicator signal may be used. The operation of the control logic 14 based on the operations of the nodes as described above is determined by the presence or absence of clocks on the upstream and downstream transmission lines in FIG. 6 and mode transitions based on incidental conditions.

〔Effect of the invention〕

As explained in detail above, the modified U-link method and
Even if the transmission medium fails and is disconnected (J +
) Since the link is established as a link system, even if a failure occurs in the transmission medium, it can operate without deteriorating its capabilities and functions, thereby providing a highly reliable data link system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram illustrating the operation of the present invention in the event of an abnormality, and FIG. FIG. 4 is an explanatory diagram showing node transition control of the present invention. FIG. 5 is a diagram showing node transition conditions of the present invention.
FIG. 7 is a block diagram showing the configuration of an embodiment of the node of the present invention; FIG. 8 is a block diagram showing an example of the configuration of the conventional technology; FIG. 9 is a block diagram illustrating the operation of the conventional technology in the event of an abnormality. Nl~NN...Node, D1~DN...
- Data terminal unit, 1oo...Uplink transmission line, 1o1-...Bottom) Transmission L102...Clock generator. Agent: Susumu Uchihara, patent attorney.・“〈・-Pa1, -1〆Fig. 7 No. 2 Zuko 3 Fig. C (1) Ripu; , 3 Glue 4C77 No. 3 Fig.

Claims (2)

[Claims] (1) Connecting a plurality of nodes in a ring to transmit data in opposite directions through transmission media divided into upstream and downstream nodes, and receiving upstream data from the upstream transmission medium on the clock source side and transmitting it to the opposite side. One mode accepts downlink data from the downlink transmission medium on the opposite side to the clock source and sends it to the downlink transmission medium on the clock source side, and the other mode accepts uplink data from the uplink transmission medium on the clock source side. There is a mode in which this is sent to the upstream transmission medium on the opposite side to the clock source and a downstream transmission medium on the clock source side, and a mode in which the clock is sent from the clock source to the upstream transmission medium as upstream data and from the upstream transmission medium on the opposite side. The received uplink data is inputted to a plurality of the nodes that can take one of the modes of transmitting the received uplink data as it is to the downlink transmission medium based on a predetermined rule. A modified U-link method comprising transmitting received data to an uplink transmission medium and outputting received data from a downlink transmission medium. (2) A transmission medium divided into uplink and downlink that connects multiple nodes in a ring and transmits data in opposite directions, and a transmission medium that receives uplink data from the uplink transmission medium on the clock source side and transmits it to the opposite side. A mode in which downlink data is received from the downlink transmission medium on the opposite side to the clock source and sent to the downlink transmission medium on the clock source side, and a mode in which uplink data is accepted from the uplink transmission medium on the clock source side and sent to the media. A mode in which the clock from the clock source is sent to the upstream transmission medium on the opposite side to the clock source and the downstream transmission medium on the clock source side, and the clock from the clock source is sent as upstream data to the upstream transmission medium and received from the upstream transmission medium on the opposite side. Based on predetermined rules, the input data is sent to the uplink transmission medium and the data received from the downlink transmission medium is transferred to the mode in which the uplink data is directly sent to the downlink transmission medium as downstream data. A modified U-link device used in a modified U-link method, comprising a plurality of the nodes for outputting.