JPS58177054A - Communication device - Google Patents

Abstract

PURPOSE:To attain the test during on-line, by transmitting a test signal which detects a failure of a communication device and a communication line even if the communication device is in operation. CONSTITUTION:A communication procedure circuit 5 controls the communication device to transmit/receive a data signal in time division, and transmits and receives a test signal in time division in response to the content of test by using the intervals of the transmission/reception of the normal data signals when a test request from a test request circuit 8 is inputted. When a loop back is set at an MODEM circuit 1, the test signal transmitted from the circuit 5 is returned to the circuit 5 via a transmission circuit 4, a line switching circuit 2, the circuit 1, a circuit switching circuit 2 and a reception circuit 3. In the signal path like this, the test signal is not returned to the circuit 5 if there exists an open line, the presence of the open line is detected and the state of the open line is displayed at a display circuit 7. Thus, even if the communication device is in operation, the reliability is kept invariably since the communication for the test is feasible at any time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to communication devices that share a communication line and cyclically transmit and receive data at predetermined intervals and cycles in a time-division manner.

It is desirable for this type of device to have a function that allows it to perform appropriate tests even during operation in order to detect failures occurring in its components or communication lines.

The present invention was made in response to such demands, and is capable of transmitting test signals to detect failures such as disconnections and short circuits in communication devices and communication lines even when the communication devices are online. The purpose is to provide a communication device that allows testing while online.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a connection diagram showing that a plurality of communication devices CMI to CMn according to the present invention are interconnected via a bus BUCK. Each communication device CMI to cnn has a configuration as shown in FIG.

In FIG. 2, 1 is a modem circuit, 2 is a line switching circuit, and data signals received from the bus BUS via the modem circuit 2 are sent to the receiving port 133 or routed to the modem circuit 1. 4 is a transmission route; -5 is a communication procedure circuit which supplies control signals for controlling the overconfident fist to each part of this communication device. 6 is modem circuit 1 and line switching circuit 2
and provide control signals to set up loop back. I
Reference numeral 8 indicates a display circuit that displays various statuses (information) in the communication i&place, and 8 a test request circuit that sends a test request (signal) to the communication procedure circuit 5.

The communication procedure circuit 5 controls the communication device to cyclically transmit and receive time-shared data signals at predetermined intervals and cycles, but when a test request is input from the test request circuit 8, the test request is is stored, and test signals corresponding to the test contents are transmitted and received in a time-sharing manner using intervals between the transmission and reception of normal data signals until there are no more test requests. Test items for this purpose include a loop back test between the transmitting circuit 4 and the receiving circuit 3, a loop back test after passing through the modem circuit 1, and a modem circuit 1 in the bus BUS and other communication devices.
There are loop back tests and the like after passing through the data signal, and since these tests are performed using the interval between normal data signal transmission and reception, they have an undesirable effect on the transmission and reception functions. Never. When loop back is set in the modem circuit 1, the test signal sent from the communication procedure circuit 5 is sent to the transmission circuit 49, line switching circuit 2. The modem circuit 19 is returned to the communication procedure circuit 5 via the line switching circuit 2 and the receiving circuit 3. In such a signal path, if there is a disconnection, the test signal is not returned to the communication procedure circuit 5, the presence of the disconnection is detected from this K, and the display circuit 7 displays the disconnection.

As mentioned above, according to the present invention, communication for testing can be performed in a timely manner even when the communication device is in operation, so that the reliability of the device can be improved without adversely affecting the original function of the device. can be retained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the connection relationship between communication devices, and FIG. 2 is a block diagram showing the configuration of the communication device. CMI to CMn...communication device, 1...modem circuit,
2... Line switching circuit, 3... Receiving circuit, 4... Transmitting circuit, 5... Communication procedure circuit, 6... Mode switching circuit, 8... Test request circuit. Agent Shin Kuzuno (1 person)

Claims (1)

[Claims] In communication devices that are interconnected via a common communication line and communicate data cyclically at predetermined intervals and cycles, in response to the input of a test request, a test signal is sent between the data communication periods. , and a communication procedure circuit that controls reception, and a mode switching circuit that controls looping back of the test signal at a specific portion using a control signal of the communication procedure circuit. Communication device.