JPH0440503A - Communication supervisory device - Google Patents

Abstract

PURPOSE:To recognize the presence or absence of a fault part such as the short of communication lines in a short time by providing a pair of line connection connectors to which the terminals of the communication lines are connected, and a pair of opening /closing means whose one end parts are connected to the line connection connectors and which can arbitrarily change over an opening state and a closing state. CONSTITUTION:A pair of line connection connectors 8a and 8b to which the terminals of the communication lines 2 are connected and the line connection switches 10 and 11 being a pair of the opening/closing means whose part are connected to the line connection connectors 8a and 8b and which can arbitrarily change over the opening state and the closing state are provided. The other end parts of the switches 10 and 11 are mutually connected and they are connected to a reception part. When one switch is set to the opening state and the other switch to the closing state in such a case, the communication line on the switch-side which is set to the opening state comes to a state where it is separated from the reception part 4. Thus, the presence or absence of the fault part such as short occurred in the communication line 2 can be recognized by switching the opening/closing state and by receiving the data signal of one communication line in the reception part 4. Thus, time required for specifying the communication line where the fault part occurs can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication monitoring device that monitors the communication status of data signals transmitted and received between a plurality of programmable controllers and host computers.

[Conventional technology]

Programmable controllers used to automatically control equipment have become capable of transmitting and receiving data signals between a plurality of programmable controllers as the number of objects to be controlled increases. In particular, recent programmable controllers have come to be connected to host computers and the like via communication lines so that the operating status of equipment and the production status of each process can be collectively managed.

At this time, if the accuracy of the data signals sent and received becomes unstable, there will be variations in processing timing etc. between each process equipped with equipment, making it difficult to maintain stable production and making it difficult to accurately monitor the production status. It becomes impossible to grasp the situation. Therefore, data signals sent and received must always be highly accurate, and communication monitoring equipment that monitors the communication status of data signals is often connected to communication lines that connect programmable controllers and host computers. ing.

Conventionally, as shown in FIG. 4, the above communication monitoring device is connected to a communication line 32 along with a node 31 that converts data signals from a programmable controller or host computer into data signals suitable for communication and transmits and receives the data signals. It is now possible to do so. This communication monitoring device 33 is
The data signals sent and received between each node 31 are taken into the receiving unit 34 via the line connector 38, and the content is analyzed by the analysis unit 35 based on the processed signal input from the operation unit 37, and then the analysis result is is displayed on the display section 36.

As a result, when a network system is constructed via the communication line 32, the communication monitoring device 33 can monitor the presence or absence of an abnormality in the communication state of data signals, and can quickly investigate the cause of the abnormality. ing.

[Problem to be solved by the invention]

However, in the conventional communication monitoring device 33 described above, although it is possible to investigate the cause of an abnormal communication state of a data signal using the operation unit 37, it is possible to investigate the cause of an abnormal communication state of a data signal by using the operation unit 37, but for example, if the communication line 32 is short-circuited and transmission/reception of data signals becomes impossible. In this case, it becomes necessary to separate the communication line 32, and it takes a long time to restore the communication line 32.

As shown in FIG. 5(a), the network system used in programmable controllers, etc. connects all nodes 31 to one communication line 32 with a terminal.
. . , and a communication monitoring device 33 are often connected to a lotus-shaped network.

In this lotus-shaped network system, even if a part of the communication line 32 develops a fault 32a such as a short circuit, the entire communication line 32 becomes unusable and data signals cannot be transmitted or received. Therefore, if this fault section 32a occurs, the data signal will not be input to the communication monitoring device 33.
Even if a processed signal is input from the operation unit 37, it is not possible to specify the direction of the communication line 32 where the faulty part 32a has occurred.

As a result, if the above-mentioned failure section 32a occurs, first, as shown in FIG. Check the presence or absence of the faulty part 32a, and then proceed as shown in Fig. 5 (
As shown in c), it is necessary to reconnect one separated communication line 32, isolate the other communication line 32, and check whether there is a faulty part 32a in one communication line 32. .

In this way, the conventional communication monitoring device 33
The direction of the communication line 32 where the faulty part 32a has occurred can be identified by repeating the process twice to isolate the faulty part 32a and confirm the presence or absence of the faulty part 32a. At this time, communication line 3
The work of separating the parts is often done using a tool such as a screwdriver, so it takes a long time to complete the work, and the delay in recovery work caused by this work is especially important for equipment where productivity is important. This is a serious problem for equipment.

Therefore, in the present invention, without separating the communication line 32, the communication line 32 in which the faulty part 32a has occurred can be removed in a short time.
The purpose of the present invention is to provide a communication monitoring device that can specify the direction of the communication.

[Means to solve the problem]

In order to solve the above problems, a communication monitoring device according to the present invention is a communication monitoring device that is connected to a communication line through which data signals are transmitted and received, receives the data signal in a receiving section, and monitors the communication state. The monitoring device consists of a pair of line connecting connectors to which the terminals of the communication line are connected, and a pair of opening/closing means for line connection, one end of which is connected to these line connecting connectors and can be switched between an open state and a closed state at will. The other end of the opening/closing means is characterized in that the other ends are connected to each other and also connected to a receiving section.

[Function] According to the above configuration, the terminals of the communication lines are connected to the pair of line connection connectors provided in the communication monitoring device, and the communication lines connected to each line connection connector are connected to each other. , and are separated around the line connector. At this time, one end of the opening/closing means is connected to each line connection connector, and the other ends of these opening/closing means are connected to each other and can be switched between an open state and a closed state at will. It has become. This results in
Both communication lines connected to the line connection connector are connected when both opening/closing means are closed, and are separated when opening/closing means are opened.

Furthermore, since the receiving section of the communication monitoring device is connected to the other end of the opening/closing means, it is connected to the communication line via the opening/closing means. Therefore, when one opening/closing means is opened and the other opening/closing means is closed, the communication line on the open opening/closing means is separated from the receiver, and the closed state is reached. Only the communication line on the side of the opening/closing means that has been set to 1 is connected to the receiving section. Therefore,
The presence or absence of a fault such as a short circuit occurring in the communication line can be confirmed by switching the opening/closing state of each opening/closing means and receiving the data signal of one communication line at the receiving unit. Confirmation by operating this opening/closing means shortens the time required to identify the communication line where the fault has occurred, and in turn makes it possible to quickly complete communication line restoration work. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The communication monitoring device according to this embodiment is adapted to be used in a system networked in the form of a bus, and as shown in FIG. Communication line 2.
It is designed to be connected to 2.

The communication monitoring device 3 described above has a pair of line connecting connectors 8a and 8b to which the terminals of the communication lines 2 and 2 are connected, and these line connecting connectors 8a and 8b are connected to the line switching unit 9. ing. The line switching unit 9 is shown in FIG.
As shown in (C), it has line connection switches 10 and 11 which are opening/closing means. One end of each of these line connection switches 10 and 11 is connected to the line connection connectors 8a and 8b shown in FIG. 1, while the other ends are connected to each other.

The line switching unit 9 also has a terminating resistance connection switch 12, and one end of this terminating resistance connection switch 12 is
It is connected to the other end of the line connection switches 10 and 11. On the other hand, the other end of the terminating resistor connection switch 12 is connected to GN
It is connected to the resistor (R) 13 connected to D,
The resistor 13 is set to a resistance value equivalent to the characteristic impedance at the terminal end of the communication line 2. Note that the above-mentioned terminating resistor connection switch 12 is the line connection switch 10.
- It is desirable that the openings be linked so that when at least one of the openings 11 is opened, the openings are closed.

As shown in FIG. 1, one end of the terminating resistor connection switch 12 and the other end of the line connection switches 10 and 11 are connected to the reception section 4 that receives data signals transmitted through the communication lines 2 and 2. The receiving section 4 converts the received data signal into a signal level and form suitable for subsequent signal processing, or converts it into a data signal suitable for transmission.

Further, the receiving section 4 is connected to an analyzing section 5 that analyzes the contents of the data signal, and this analyzing section 5 is operated by an operator that can input a processing signal that instructs how to process the data signal or monitor the communication state. It is connected to the display section 7 and also to the display section 6 that displays processing results, analysis results, and the like.

In the above configuration, the operation of the communication monitoring device 3 when a fault such as a short circuit occurs in the communication lines 2 will be described.

If there is no faulty part in communication line 2.2, Fig. 2(a)
As shown in FIG. 2, the line connection switches 10 and 11 are closed, and the terminating resistor connection switch 12 is opened. As a result, the communication lines 2 and 2 are connected to each other via the line connection switches 10 and 11 of the line switching section 9, and as shown in FIG. Each communication line 2.2 centered on
Data will also be sent and received between two connected devices. The communication monitoring device then monitors the communication status of the above-mentioned transmitted and received data signals.

On the other hand, as shown in FIG. 3, if a fault such as a short circuit occurs in some of the communication lines 2,
・Since 2 becomes short-circuited, it becomes impossible to send and receive data signals. Therefore, in this case, as shown in FIG. 2(b), first, the line connection switch 11 of the line switching section 9
is brought into an open state, and the terminating resistor connection switch 12 is brought into a closed state. As a result, the communication line 2 connected to the line connection switch 11 is connected to the communication monitoring device 3.
The state is the same as when the communication line 2 on the line connection switch 10 side is connected to the receiving unit 4 in FIG. 1. Then, the communication monitoring device 3 determines whether data signals can be transmitted and received through the connected communication line 2, and confirms the presence or absence of the faulty part 2a.

Next, as shown in FIG. 2(C), the line connection switch 10 of the line switching unit 9 is opened, and the line connection switch 11 and the terminating resistor connection switch 12 are closed. Become.

As a result, the communication line 2 connected to the line connection switch 10 becomes in a state equivalent to being separated from the communication monitoring device 3, and the receiving unit 4 in FIG. Only line 2 is connected. Then, the communication monitoring device 3 determines whether data signals can be transmitted and received through the connected communication line 2, and confirms the presence or absence of the faulty section 2a.

In this way, the communication monitoring device 3 of this embodiment has the communication line 2
- If a fault such as a short circuit occurs in 2 and it becomes impossible to send and receive data signals, simply operate the line connection switches 10 and 11 and the terminating resistor connection switch 12 of the line switching unit 9. It is now possible to specify the communication line 2 where the faulty part 2a has occurred. Therefore, this communication monitoring device 3 can quickly monitor the communication lines 2 and 2 that have the faulty part 2a.
It becomes possible to identify the communication line 2.
This makes it possible to shorten the time required for recovery.

〔Effect of the invention〕

As described above, the communication monitoring device according to the present invention includes a pair of line connecting connectors to which terminals of a communication line are connected, and one end portion is connected to these line connecting connectors, and can be switched between an open state and a closed state at will. a pair of opening/closing means,
The other ends of the opening/closing means are connected to each other and to the receiving section.

As a result, each communication line connected to a pair of line connecting connectors is connected when the opening/closing means is closed, and separated when the opening/closing means is opened. By switching the opening/closing state of each opening/closing means and receiving the data signal of one communication line at the receiving section, it is possible to check whether there is a fault such as a short circuit, and to check whether there is a fault such as a short circuit. This has the effect that the time required for identification can be shortened.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention. FIG. 1 is a block diagram of a communication monitoring device connected to a communication line. FIGS. 2(a) to 2(c) are explanatory diagrams showing the open and closed states of each switch provided in the line switching section. FIG. 3 is an explanatory diagram showing the communication line that caused the fault. 4 and 5 show conventional examples. FIG. 4 is a block diagram of a communication monitoring device connected to a communication line. FIGS. 5(a) to 5(c) are explanatory diagrams showing a communication line in which a faulty portion has occurred. ■ is a node, 2 is a communication line, 2a is a failure part, 3 is a communication monitoring device, 4 is a reception part, 5 is an analysis part, 6 is a display part, 7 is an operation part, 8a and 8b are line connection connectors, 9 is a Line switching unit, 10 and 11 are line connection switches (opening/closing means), 12
is a terminal resistor connection switch, and 13 is a resistor.

Claims (1)

[Claims] 1. A communication monitoring device that is connected to a communication line through which data signals are transmitted and received, receives the data signal in a receiving section, and monitors the communication state, which includes a pair of communication monitoring devices to which terminals of the communication line are connected. It has a line connecting connector, and a pair of opening/closing means whose one end is connected to the line connecting connector and can be arbitrarily switched between an open state and a closed state, and the other end of the opening/closing means is A communication monitoring device characterized in that the communication monitoring device is connected to the receiver and is connected to the receiver.