JPH08125716A - Line error factor color-coded display circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a line error factor color-coded display circuit capable of easily determining the factor of a line error. [Structure] A modem device connected to a line, and a CD output means for extracting a carrier detect signal of the modem device,
SQD output means for extracting the SQD signal of the modem device, and multicolors that can be distinguished from each other according to a combination mode of the state of the carrier detect signal from the CD output means and the state of the SQD signal from the SQD output means. A multicolor light emitting LED for displaying an error factor for displaying, wherein the multicolor light emitting LED is configured to emit light in a predetermined color among multicolors that can be colored according to the error factor of the line. There is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for displaying a cause of a line error when a line error occurs in data communication through a line using a modem.

[0002]

2. Description of the Related Art Conventionally, in displaying an error of a line in a modem device, a monochromatic LED is generally used to notify the error to the outside. For example, when an error occurs with respect to data input to the modem from a public line or a dedicated line, a monochromatic LED installed in the modem is turned on.

[0003]

However, in the case of this display, it was necessary to install a monochromatic LED for each cause of the line error. The specific cause of the line error is a CRC (Cyclic Redundancy Check) error that occurs when the data input to the modem changes during transmission, and the carrier wave (carrier signal) of the modem turns off. Error that occurs due to the occurrence of SQD (Si
gnal Quality Detector) There is an abnormality, and in order to monitor all of these error factors, it is necessary to install as many monochromatic LEDs as there are error factors, and there is a problem in mounting the LEDs. Further, in detecting an error due to a CRC error, if a single-color LED is used to know how many times the CRC error has occurred, the number of errors cannot be counted and it is difficult to check the line quality. Met.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a line error factor color-coded display circuit capable of easily determining the cause of a line error in order to solve the above-mentioned problems of the prior art.

[0005]

In order to achieve this object, a circuit for color-coded line error factors according to the present invention includes a modem device connected to a line and a CD output for extracting a carrier detect signal of the modem device. Means, SQD output means for taking out the SQD signal of the modem device, and a state of the carrier detect signal from the CD output means and a state of the SQD signal from the SQD output means, which are distinguished from each other. A multicolor light emitting LED for displaying one of the obtained error factors for displaying an error factor so that the multicolor light emitting LED emits light in a predetermined color among the multicolors that can be colored according to the error factor of the line. It is configured.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structural example of the present invention. Here, 1 is a public line or a dedicated line input to the modem device, 2 is the modem device main body, 3 is a CD (carrier detect) signal for detecting whether or not a carrier wave is input from the line 1, and 4 is SQD signal, 5 is a reception signal for outputting the data input from the line 1 to the line controller 8 from the modem device 2, 6 is a buffer for driving the LED,
Reference numerals 7 and 7 ′ are multicolor LEDs, and 8 is a line controller that receives and analyzes the data output from the modem device 2. The main point of the present invention is that the multicolor LEDs 7 and 7'in FIG. 1 are used and the cause of the line error can be determined by the color coding of the LEDs. Here, an example in which a three-color display LED is used will be described.

Next, this operation will be described step by step. The data from the line 1 is input to the modem device 2, where the data of the AC level is demodulated into the signal of the DC level and then returned to the line controller 8. At this time, if a line error occurs inside the modem device 2, an LED is generally used as a method of notifying the error to the outside.

In the present invention, by using a multicolor LED 7 (for example, an LED capable of displaying three colors of green, orange and red), if the circuit is normal, the modem device 2
Since the CD signal 3 output from the device outputs the "L" level, the a of the light emitting LED 7 is turned on via the buffer 6.

If the SQD is abnormal, the level of the SQD signal 4 becomes "L" level, and therefore the LE is passed through the buffer 6.
Since the b of D7 is turned on, it is possible to detect that the SQD abnormality has occurred from the outside by changing the color of the LED7 which was normal.

When the carrier signal is turned off, the CD
Since the level of the signal 3 becomes "H", the light emission of the LED 7 changes. Therefore, one LED can identify the cause of the line error.

Further, when an error occurs at the time of CRC check, the number of CRC errors can be identified as follows by preparing, for example, two types of output ports by internal I / O of the line controller 8. . That is, when the number of CRC errors is 1 to 10, the output port (A) of the line controller 8 is set to "L".
Level, output port (B) to "H" level and LED
Light 7'in orange. CRC error count is 5
If it is 0 or more times, set the output port (A) to "H" level,
The output port (B) is set to "L" level and the LED 7'is illuminated in red.

By the above operation, with a small number of LEDs,
The cause of the line error can be easily identified.

[0013]

As described in detail above, according to the present invention, the following special effects can be obtained. (1) When a CRC error occurs, the number of occurrences of the CRC error can be easily identified by the difference in the LED emission color. (2) Error due to SQD error and carrier signal OFF
It is possible to easily identify an error or the like due to the color difference of one multicolor LED. (3) Since the cause of the line error can be identified by the multi-colored LEDs without using a 7-segment LED, cost reduction can be expected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of the present invention.

[Explanation of symbols]

 1 Line 2 Modem Device 3 CD (Carrier Detect) Signal 4 SQD Signal 5 Received Signal 6 Buffer 7, 7'Multicolor LED 8 Line Controller

Claims (2)

[Claims] 1. A modem device connected to a line and a CD for extracting a carrier detect signal from the modem device.
Output means, SQD output means for taking out the SQD signal of the modem device, and distinguishing from each other according to a mode of a combination of the state of the carrier detect signal from the CD output means and the state of the SQD signal from the SQD output means. And a multicolor light emitting LED for displaying an error factor, which enables multicolor display, so that the multicolor light emitting LED emits light in a predetermined color among the multicolors that can be colored according to the error factor of the line. Error-coded color-coded display circuit configured in. 2. A reception signal output means for extracting a reception output signal of the modem device, the reception output signal extracted by the reception signal output means, and the carrier detect signal extracted by the CD output means. The line controller that extracts the CRC error check result by the cyclic redundancy check and the predetermined number of colors that can be colored according to which of the predetermined error number divisions the error count based on the CRC error check result is in. The line error factor color-coded display circuit according to claim 1, further comprising: a multicolor LED for displaying the number of errors, which emits light in colors.