JPH11177509A - Modem - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly analyze a circuit fault by lighting up continuously an alarm lamp when a carrier signal is interrupted after monitoring the carrier detection signal sent from a demodulation part set via an operation part. SOLUTION: A modulation part(MOD) 2 is subjected to the setting control via a control part 6, and an operation part 7 monitors the part 6 to detect a carrier interruption state. Thus, the part 6 monitors the carrier detection signal sent from a demodulation part(DEM) 4 with respect to a carrier interruption detection circuit 10. Then the part 6 continuously lights up a carrier interruption alarm lamp 9 as long as the carrier interruption state is once detected. In this case, it is possible to confirm that the carrier interruption state occurred once in the past by preparing the circuit 10 which monitors the carrier detection signal sent from the DEM 4 and the lamp 9 which displays an alarm signal at a receiving part. As a result, a circuit fault can be smoothly analyzed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modem.

[0002]

FIG. 2 shows a prior art example of the present invention. In the figure, 1 is a modem, 2 is a modulation unit (MOD), 3 is a transmission line output terminal, 4 is a demodulation unit (DEM), 5 is a reception line input terminal, 6 is a control unit (CNT), and 7 is an operation unit (OP). )
And 8, a carrier detection lamp (CD).

In the conventional modem 1, a carrier is detected by a demodulation unit 4 from a signal input from a reception line input terminal 5, and a signal at the time of the detection is transmitted to a carrier detection lamp 8.
And the lights are turned off when the carrier at that time is cut off and when the carrier is detected.

[0004]

The above-mentioned prior art includes the following:
The state at the time of carrier reception is displayed in real time by a carrier detection lamp which is extinguished when the carrier is disconnected and lit when a carrier is detected. Therefore, only the state of the modem at that time could be confirmed, and it was not known whether or not the carrier was disconnected in the past.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to make it possible to confirm when a carrier disconnection has occurred at least once in the past, thereby making it possible to smoothly analyze a line failure. To be able to do it.

[0006]

In order to achieve the above object, a modem device according to the present invention comprises a receiving section for monitoring a carrier detection signal from a demodulation section and a carrier disconnection detection circuit for displaying an alarm signal thereof. By having a disconnection alarm lamp, it is possible to confirm when a carrier disconnection has occurred at least once in the past.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a diagram showing an example of a block configuration of a modem according to the present invention. Reference numeral 11 denotes a modem in the embodiment of the present invention, and 2 denotes a modulation unit (MOD) which is controlled by a control unit. Reference numeral 3 denotes a transmission line output terminal connected to a transmission line. Reference numeral 4 denotes a demodulation unit (DEM) which receives setting control from a control unit. Reference numeral 5 denotes a reception line input terminal, which is connected to a transmission line. Reference numeral 6 denotes a control unit (CNT) for setting and controlling each unit of the modem in accordance with an input from the operation unit. Reference numeral 7 denotes an operation unit (OP) for setting a modem.
Reference numeral 8 denotes a carrier detection lamp (CD), which displays a carrier state based on a carrier detection signal from a demodulation unit.

Reference numeral 9 denotes a carrier disconnection alarm lamp (CDA).
(LARM), when the carrier is cut off, the display is turned on by a signal from the carrier cut-off detection circuit. Reference numeral 10 denotes a carrier disconnection detection circuit that detects a carrier disconnection based on a carrier detection signal of the demodulation unit 4.

Hereinafter, this operation will be described. First, a monitoring setting is performed from the operation unit 7 to the control unit 6 so as to detect the carrier disconnection. The control unit 6 monitors the carrier detection signal from the demodulation unit 4 with respect to the carrier disconnection detection circuit 10 according to the monitoring setting from the operation unit 7, and sets so that the carrier disconnection alarm lamp continues to be turned on even if the carrier is disconnected even once. I do.

[0011]

As described in detail above, according to the present invention,
Since the receiving unit has a carrier disconnection detection circuit for monitoring the carrier detection signal from the demodulation unit and a carrier disconnection alarm lamp for displaying the alarm signal, it is possible to confirm when the carrier disconnection has occurred at least once in the past. With this function, failure analysis of the line can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a block configuration of a conventional modem.

[Explanation of symbols]

1: Modem, 2: Modulation unit (MOD), 3: Transmission line,
4: demodulation unit (DEM), 5: reception line, 6: control unit (CNT), 7: operation unit (OP), 8: carrier detection signal lamp (CD), 9: carrier disconnection alarm lamp (C
DALARM), 10: Carrier disconnection detection circuit (CD
D), 11: Modem.

Claims (1)

[Claims] 1. A modem for monitoring a carrier detection signal from a demodulation unit according to a setting from an operation unit and continuously turning on an alarm lamp when the carrier signal is interrupted. Modem.