JPH0215743A - On-line monitoring system for ring type lan - Google Patents

Abstract

PURPOSE:To monitor communication between terminals at an arbitrary position on a ring by providing a slot for monitoring to a node device housing a terminal to be monitored separately from a slot used for inter-terminal communication. CONSTITUTION:Node devices 7 and 8 are formed in such ways that they can replace contents of received slots on slots for monitoring. When terminals-A and -B make communication with each other, the transmitting data of the terminal-A are multiplexed to a prescribed slot for communication by means of the node device 7. Then the transmitting data pass through and are monitored by a node device 6 for monitoring also before the data are inputted to a node device 8 incorporating the terminal-B and the monitored content is outputted to a monitoring device 5. Then the content of the above-mentioned slot for communication is outputted to the terminal-B as receiving data and the slot is rewritten by the transmitting data from the terminal-B at the node device 8. The data are outputted to the terminal-A as receiving data and, at the same time, replaced to the slot for monitoring at the node device 7.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a method for monitoring communication between terminals connected to two nodes in a time division multiplexed ring LAN at a third node. The present invention relates to an online monitoring method for a ring type LAN.

[Prior Art] FIG. 4 is a diagram showing an online monitoring system in a conventional time division multiplexing ring type LAN disclosed in, for example, Japanese Unexamined Patent Publication No. 62-254549. In the figure, 1 and 2 are communicating terminals A and B, 3 and 4 are node devices for accommodating terminal A1 or terminal B2 in the ring, respectively, and 5 is a node device for accommodating communication between terminal A1 and terminal 82. A monitor device 6 is a node device for monitoring and intercepts and outputs communication between both terminals AI 82 to the monitor device 5.

Next, the operation will be explained. The transmission data of the terminal AI is multiplexed into a predetermined time division slot by the node device 3,
The node device 4 outputs the contents of the slot as received data to the terminal B2, and also outputs the content of the slot to the terminal B2.
Rewrite with more sent data. This data is output by the node device 3 to the terminal A1 as received data, as in the node device 4. At this time, in order to monitor the communication between terminal A1 and terminal B2, node devices 6 are provided before and after node device 3 or node device 4, and each intercepts the above slot and outputs it to monitor device 5.

[Problem to be solved by the invention]

Since the conventional monitor method is configured as described above,
Monitoring node devices must be installed before and after the node device that accommodates the monitored terminal, and it is impossible to monitor communication between arbitrary terminals without changing the position of the monitoring node device on the ring. There was a problem.

This invention was made to solve the above-mentioned problems, and provides a ring-type LAN that makes it possible to monitor communication between arbitrary terminals by providing one monitoring node device on the ring. The purpose is to obtain a monitoring method for

[Means to solve the problem]

In the ring-type LAN online monitoring method according to the present invention, in a node device that accommodates a monitored terminal, the contents of a receiving slot are output to the terminal as received data, and the contents are also output to a monitoring slot other than a communication slot. The same content is multiplexed and sent to the ring.

(Function) Since the monitoring node device according to the present invention has the above-mentioned functions, it can intercept the communication slot and the monitor slot at any position on the ring.
@ You can monitor end time.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 7 and 8 are node devices that are capable of transferring the contents of a receiving slot to a monitoring slot. However, the rest of the configuration is the same as the conventional device described with reference to FIG.

Next, the operation will be explained. Assume that terminal A and terminal B are currently communicating. Transmission data from terminal A is multiplexed into a predetermined communication slot by node device 7. Before this transmission data is input to the node device 8 in which the terminal B is accommodated, it also passes through the monitoring node device 6, is intercepted, and is output to the monitor device 5. Next, the node device 8
In , the contents of the communication slot are outputted to terminal B as received data, and this slot is rewritten and rewritten by transmitted data from terminal B. This data is output as received data to the terminal AI in the node device 7 and is transferred to the monitor slot. The monitor node device 6 outputs this monitor slot to the monitor device 5. As a result of the above, the monitor device 5
It becomes possible to monitor the transmitted data of both terminal A1 and terminal B2.

The above-mentioned node devices 7 and 8 can be realized by configuring them as shown in FIG. 2, for example. That is, the ring multiplexing/demultiplexing section 21 shown in the figure converts the received data on the ring into a parallel signal for each slot and outputs it to the internal bus 22. are simultaneously multiplexed and sent out to the ring using a strobe signal output from the terminal support section 23.

The terminal correspondence section 23 identifies the slot to receive from the address signal and inputs it to the latch 9. The data in this slot is converted into a serial signal by the P/S conversion circuit 10 and output to the terminal. At the same time, the gate 11 is
The transmission data converted into parallel data by the P conversion circuit 12 is output to the internal bus 22. If it is set to accommodate a monitored terminal, the monitor slot is identified from the address signal, and at that timing, the output of the latch 9, that is, the received data itself, is sent to the bus via the gate 13. Output. In the figure, 14 is a control circuit that controls the operation of the terminal support section 23, decodes the address signal on the internal bus 22, and creates a transmission strobe signal and others.

Note that in the above embodiment, among the node devices accommodating the monitored terminal, the monitor slot is rewritten only in the downstream node device on the ring when viewed from the monitor node device. In a configuration where the transmission directions within each ring are opposite to each other, the winter lot for monitoring should be rewritten in advance at both nodes that accommodate the monitored terminals, taking into consideration when switching the rings used. You can do it like this.

That is, this embodiment will be explained with reference to FIGS. 3(a) and 3(b).

In FIG. 3(a), as in FIG. 1, the monitor node device 6
, the transmission data of terminal A1 is sent from the predetermined communication slot,
The transmission data of terminal B2 is taken out from the monitor slot and monitored, but when the duplex ring is switched, the transmission direction is reversed as shown in Figure 3(b), so the transmission data of terminal AI is from the monitor slot, and the transmission data of terminal B2 from a predetermined communication slot for monitoring. If this is taken into consideration, as in this embodiment, the node devices 7 and 8 should read the data to the monitor slot in advance. It is a good idea to change the vehicle in advance.

(Effects of the Invention) As described above, according to the present invention, a node device accommodating a monitored terminal is provided with a monitoring slot in addition to a slot used for communication between terminals, so that an arbitrary This has the effect of allowing communication between terminals to be monitored based on location.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a monitoring system according to an embodiment of the present invention, FIG. 2 is a specific block diagram of a node device 7.8, and FIG.
The figure is a configuration diagram of a monitor system showing another embodiment of the present invention.
FIG. 4 is a block diagram showing a conventional monitor system. 1 and 2 are terminals A and B (monitored terminals), 5 is a monitor device, and 6.7.8 is a node device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Figure 1 (2 other people) 7.8: Node 1 Figure History Imiya Te 1 Figure

Claims (1)

[Claims] In an online monitoring method for a ring-type LAN that includes a node device that accommodates monitored terminals in a time division multiplexed LAN, the node device outputs the contents of a reception slot to the terminal as reception data, and also outputs the contents of a reception slot to the terminal as reception data. An online monitoring system for a ring-type LAN, characterized in that the same content as the above is multiplexed so as to be output to a separately allocated monitor slot.