CN201413376Y

CN201413376Y - Detecting circuit of signal outputting port

Info

Publication number: CN201413376Y
Application number: CN2009201082465U
Authority: CN
Inventors: 陈风波; 宋建立
Original assignee: Beijing Rongda Qianli Technology Co Ltd
Current assignee: Beijing Rongda Qianli Technology Co Ltd
Priority date: 2009-05-22
Filing date: 2009-05-22
Publication date: 2010-02-24
Anticipated expiration: 2019-05-22

Abstract

The utility model discloses a signal level detecting circuit based on line high-resistance cross-connection. The circuit utilizes a resistor (with the resistance 10 times higher than the resistance ofa normal resistor) to have the cross connection with an original outputting circuit, wherein the normally-received impedance of the resistor is greatly higher than that of the circuit; and under thecondition that the normal reception of transmission equipment is ensured, certain signals (less than 5 percent) are distributed, and open-circuit and short-circuit conditions of a connecting cable arejudged by detecting signal level values.

Description

A kind of signal output observation circuit

Technical field

The utility model relates to communications and monitoring, relates in particular to a kind of signal output observation circuit based on the circuit high resistant cross-over connection.

Background technology

When the connection transmission equipment communicates, under each apparatus output signal normal condition, sometimes because the short circuit or the open circuit of interface cable or connector cause communication disruption.Because it is equipment output port does not have self-monitoring function, when such fault occurring, usually difficult: as if according to the generic failure treatment scheme, need after accuse the Shen of receiving receiving end, to carry out loopback, test with instrument again to whole communication line with identification; The very long Diagnostic Time of cost comes the fault location point.

The utility model content

The purpose of this utility model provides a kind of original delivery outlet that is connected across, and amplitude output signal is monitored, and can distinguish the open circuit of stube cable, the signal output observation circuit of short-circuit conditions by judging signal level.

For achieving the above object, the technical solution adopted in the utility model is as follows:

A kind of signal output observation circuit comprises: the cross-over connection high resistant of the delivery outlet level that is used to sample, first comparer that sampled level and open circuit decision level are compared, second comparer, first counter that is used for the output open circuit pulse, second counter that is used for the output short-circuit pulse that sampled level and short circuit decision level are compared, be used for to first counter and second counter carry out zero clearing the 3rd counter, be used to produce and open a way and the level generating circuit of short circuit decision level;

The output port that is used to export monitored signal is received one of them input end of described first comparer and described second comparer by described cross-over connection high resistant, the other end of described first comparer links to each other with the open circuit level signal that described level generating circuit produces, the other end of described second comparer links to each other with the short circuit level signal that described level generating circuit produces, the Enable Pin of described first comparer output control, first counter, the Enable Pin of described second comparer output control, second counter.

The beneficial effects of the utility model:

The utility model has utilized the high-ohmic cross-connection technology, for signal output port increases the monitoring that cable connects, helps getting rid of fast because the fault that line short or open circuit cause.

Description of drawings

Fig. 1 is a principle schematic of the present utility model.

Embodiment

Referring to accompanying drawing 1, a specific embodiment of the present utility model is as follows:

Resistance R 1, R2, R3 form level generating circuit, by dividing potential drop generation open circuit decision level and the short circuit decision level of resistance R 1, R2, R3; Signal is received one of them input end of first comparer and second comparer by cross-over connection high resistant (generally greater than 10 times resistance), the other end of first comparer is received known open circuit decision level, and the other end of second comparer is received known short circuit decision level.

First comparer compares the signal level of sampling (decision level of opening a way be normal level 150%) with known open circuit decision level, if signal level is greater than the open circuit decision level, then high level of first comparer output makes the first counter operate as normal, otherwise the first comparer output low level, first counter is not worked;

The signal level and the known short circuit decision level of sampling compared (short circuit decision level be normal level 50%) with second comparer, if signal level is less than the short circuit decision level, then high level of second comparer output makes the second counter operate as normal, otherwise the second comparer output low level, second counter is not worked;

Quenching pulse of per 64 clock period output of the 3rd counter;

When open circuit, the first counter operate as normal (second counter quits work), first counter can be exported a pulse when counting down to 64 clock period, the pulse of promptly opening a way, quenching pulse of the 3rd counter output simultaneously carries out zero clearing to first counter and resets, and restarts the next count cycle;

When short circuit, the second counter operate as normal (first counter quits work), second counter can be exported a pulse when counting down to 64 clock period, it is short circuit pulse, quenching pulse of the 3rd counter output simultaneously carries out zero clearing to second counter and resets, and restarts the next count cycle.

Claims

1, a kind of signal output observation circuit is characterized in that comprising: the cross-over connection high resistant of the delivery outlet level that is used to sample, first comparer that sampled level and open circuit decision level are compared, second comparer, first counter that is used for the output open circuit pulse, second counter that is used for the output short-circuit pulse that sampled level and short circuit decision level are compared, be used for to first counter and second counter carry out zero clearing the 3rd counter, be used to produce and open a way and the level generating circuit of short circuit decision level;