JP2806127B2 - Signal conversion circuit between bipolar signals and unipolar signals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conversion circuit for performing mutual signal conversion between a bipolar signal and a unipolar signal.

[0002]

2. Description of the Related Art A bipolar signal is one of baseband signals used for data transmission. FIG. 2 is a block diagram showing a conventional signal conversion circuit for converting a unipolar data signal into a bipolar signal and sending it out to a transmission line, and converting a bipolar signal from the transmission line into a unipolar data signal. As shown in this figure, the conventional signal conversion circuit
A unipolar / bipolar converter (hereinafter, referred to as a U / B converter) 1 that converts a unipolar data signal 11 into a bipolar signal 12 and sends it out to a transmission path, and receives a bipolar signal 22 from the transmission path and receives unipolar data Signal 21
To a bipolar / unipolar converter (hereinafter referred to as B /
It is described as a U converter. 2) and a frame synchronization circuit 7 for performing frame synchronization based on the data output from the B / U converter 2.

[0003]

By the way, in the conventional signal conversion circuit, when a failure occurs in the B / U converter 2, the frame synchronization circuit 7 loses synchronization, so that the occurrence of the failure can be detected. Although it is possible, it is difficult to identify the location of the failure, and there is a problem that it is impossible to identify whether the failure is due to a failure in the game device, a failure in the own station device, or a failure in the transmission path.

[0004] When a failure occurs in the U / B converter 1, it is possible to detect the occurrence of a failure by causing the playing device to lose frame synchronization, but similarly, it is difficult to specify the location of the failure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a signal conversion circuit between a bipolar signal and a unipolar signal which can specify a fault location when a fault occurs.

[0006]

According to a first aspect of the present invention, there is provided a signal conversion circuit for converting a bipolar signal to a unipolar signal, comprising the steps of: , A bipolar-unipolar converter that receives a bipolar signal from a transmission line and converts it into a unipolar data signal, and converts an output bipolar signal of the unipolar-bipolar converter and an input bipolar signal of the bipolar-unipolar converter into a unipolar data signal High-input impedance bipolar-unipolar converter, the output data signal of this high-input impedance bipolar-unipolar converter, and the input unipolar data signal of the unipolar-bipolar converter or the output unipolar data signal of the bipolar-unipolar converter It is obtained by a comparison means for detecting a data error by comparing the.

In this signal conversion circuit, the output bipolar signal of the unipolar / bipolar converter and the input bipolar signal of the bipolar / unipolar converter are converted into a unipolar data signal by the high input impedance bipolar / unipolar converter, and are compared by the comparing means. By detecting a data error by comparing the output data signal of the high-input impedance bipolar-unipolar converter with the input unipolar data signal of the unipolar-bipolar converter or the output unipolar data signal of the bipolar-unipolar converter, Can be specified.

According to a second aspect of the present invention, there is provided a signal conversion circuit for converting a bipolar signal to a unipolar signal, a unipolar / bipolar converter for inputting a unipolar data signal, converting the data into a bipolar signal, and transmitting the converted signal to a transmission line, and a bipolar signal from the transmission line. Bipolar-to-unipolar converter that receives signals and converts them to unipolar data signals; inputs unipolar data signals to unipolar / bipolar converters and outputs unipolar data signals to bipolar / unipolar converters; selects and outputs one A first selection means and a unipolar
The output bipolar signal of the bipolar converter and the bipolar
A second selecting means for inputting an input bipolar signal of the unipolar converter and selecting and outputting one of the input signals; a high input impedance bipolar / unipolar converter for converting an output signal of the second selecting means into a unipolar data signal; And comparing means for comparing the output data signal of the high input impedance bipolar unipolar converter with the output data signal of the first selecting means to detect a data error.

In this signal conversion circuit, the first selection means selects the input unipolar data signal of the unipolar / bipolar converter, and the second selection means selects the output bipolar signal of the unipolar / bipolar converter. By converting the output bipolar signal of the unipolar bipolar converter into a unipolar data signal by a high input impedance bipolar unipolar converter and comparing it with the input unipolar data signal of the unipolar bipolar converter by comparing means, the unipolar bipolar converter Can be detected. Similarly, while selecting the output unipolar data signal of the bipolar unipolar converter by the first selecting means,
The input bipolar signal of the bipolar / unipolar converter is selected by the second selecting means, the input bipolar signal of the bipolar / unipolar converter is converted into a unipolar data signal by the high input impedance bipolar / unipolar converter, and the bipolar data is outputted by the comparing means. A failure of the bipolar-unipolar converter can be detected by comparing the output with the unipolar data signal of the unipolar converter.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a signal conversion circuit between bipolar signals and unipolar signals according to one embodiment of the present invention.

The signal conversion circuit of the present embodiment converts a unipolar data signal 11 into a bipolar signal 12 and sends it out to a transmission line, and receives a bipolar signal 22 from the transmission line and outputs a unipolar data signal. The B / U converter 2 converts the data into a signal 21, and the frame synchronization circuit 7 performs frame synchronization based on data output from the B / U converter 2.

The signal conversion circuit further includes a self-diagnosis function for input unipolar data signal 11 of U / B converter 1.
And a selector (1) 3 for inputting the output unipolar data signal 21 of the B / U converter 2 and selecting and outputting one of them.
A selector (2) 4 for inputting the output bipolar signal 12 of the / B converter 1 and the input bipolar signal 22 of the B / U converter 2 and selecting and outputting one of them, and an output signal of the selector (2) 4 A high input impedance B / U converter 5 having an input impedance of high impedance for converting into a unipolar data signal;
An alarm detector 6 for comparing the output data signal of the / U converter 5 with the output data signal of the selector (1) 3 to detect a data error and output an alarm signal 8 is provided.

Next, the operation of this embodiment will be described. First, when the selector (1) 3 and the selector (2) 4 both select the signal on the U / B converter 1 side, the output bipolar signal 12 of the U / B converter 1 has a high input impedance B
The signal transmitted to the transmission line is monitored by the / U converter 5 without any influence, and is converted into a unipolar data signal. Then, this unipolar data signal and the input unipolar data signal 1 of the U / B converter 1 which is the output of the selector (1) 3
1 is compared by the alarm detector 6. U
When the / B converter 1 is operating normally, the two input signals of the alarm detector 6 match. If they do not match, it can be detected that a failure has occurred in the U / B converter 1. When two input signals do not match, the alarm detector 6 outputs an alarm signal 8 to notify the occurrence of a failure.

Similarly, when the selector (1) 3 and the selector (2) 4 both select the signal on the B / U converter 2 side, the input bipolar signal 22 of the B / U converter 2 has a high input impedance B / U. Monitored by the U converter 5,
It is converted to a unipolar data signal. Then, the unipolar data signal and the output B / of the selector (1) 3 are output.
The output unipolar data signal 21 of the U converter 2 is compared by the alarm detector 6 to detect a failure of the B / U converter 2.

In this embodiment, the selectors 3 and 4 for selecting the signal on the U / B converter 1 side and the signal on the B / U converter 2 side are provided, so that the high input impedance B / B
Only one U converter 5 and one alarm detector 6 are required. Note that, without providing the selectors 3 and 4,
A high input impedance B / U converter 5 and an alarm detector 6 may be separately provided for the signal on the U / B converter 1 side and the signal on the B / U converter 2 side.

[0016]

As described above, according to the present invention, the output bipolar signal of the unipolar / bipolar converter and the input bipolar signal of the bipolar / unipolar converter are converted into the unipolar data signal by the high input impedance bipolar / unipolar converter. Convert and compare the output data signal of the high-input impedance bipolar-unipolar converter with the input unipolar data signal of the unipolar-bipolar converter or the output unipolar data signal of the bipolar-unipolar converter, and detect a data error. Therefore, there is an effect that a fault location can be easily specified when a fault occurs.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a signal conversion circuit between bipolar signals and unipolar signals according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional signal conversion circuit between bipolar signals and unipolar signals.

[Explanation of symbols]

 Reference Signs List 1 U / B converter 2 B / U converter 3 Selector (1) 4 Selector (2) 5 High input impedance B / U converter 6 Alarm detector 7 Frame synchronization circuit

Claims (2)

(57) [Claims] 1. A unipolar / bipolar converter for inputting a unipolar data signal and converting it into a bipolar signal and sending it out to a transmission line, and a bipolar / unipolar converter receiving a bipolar signal from the transmission line and converting it into a unipolar data signal A high-input impedance bipolar-unipolar converter that converts an output bipolar signal of the unipolar-bipolar converter and an input bipolar signal of the bipolar-unipolar converter into a unipolar data signal; and a high-input impedance bipolar-unipolar converter. A comparison means for comparing the output data signal with an input unipolar data signal of the unipolar / bipolar converter or an output unipolar data signal of the bipolar / unipolar converter to detect a data error. A signal conversion circuit between bipolar signals and unipolar signals. 2. A unipolar / bipolar converter for inputting a unipolar data signal, converting it into a bipolar signal and sending it out to a transmission line, and a bipolar / unipolar converter receiving a bipolar signal from the transmission line and converting it into a unipolar data signal. A first selecting means for inputting the input unipolar data signal of the unipolar / bipolar converter and the output unipolar data signal of the bipolar / unipolar converter, selecting and outputting one of the unipolar / bipolar converter, and the unipolar / bipolar converter Second selecting means for inputting an output bipolar signal and an input bipolar signal of the bipolar-unipolar converter and selecting and outputting one of them; and a high input for converting an output signal of the second selecting means into a unipolar data signal Impedance bipolar unipolar converter and this high input impedance A signal between a bipolar signal and a unipolar signal, comprising: comparison means for comparing the output data signal of the dance bipolar / unipolar converter with the output data signal of the first selection means to detect a data error. Conversion circuit.