JPH039654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an analog signal transmission system that is equipped with a level setting function that can easily set the transmission signal level in a short time in an analog signal transmission system that performs bidirectional signal transmission.

FIG. 1 is a block diagram showing a conventional optical transceiver. An analog signal transmission system will be explained using an example of an optical transceiver that performs bidirectional transmission using optical fiber. Each optical transceiver 1 includes an optical transmitter 2, an optical splitter 3, an optical receiver 4, and an amplifier 5.
The optical transceiver 1 of the other party is connected to the optical branch 3 and the optical fiber 6 to transmit and receive optical signals. This optical transmitter/receiver 1 needs to have an input/output level of a signal to be transmitted within a certain range, and usually the receiver side is provided with a level adjustment function in order to set the output level to a specified level. When performing this level adjustment, connect a signal generator to the input on the transmitting side and a level meter to the output on the receiving side to communicate between the two points. There were disadvantages such as having to go back and forth between the two points to adjust the level, preparing a measuring device, and going back and forth between two points, which was time consuming and inefficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide an analog signal transmission system equipped with a level setting function that enables smooth setting of the level of a transmitted analog signal in a short time in an analog signal transmission system that performs bidirectional signal transmission. be.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the analog signal transmission system of the present invention. The analog signal transmission system will be explained using an example of an optical transceiver as in FIG. 1. Although the optical transceiver 10 and the optical transceiver 10' are exactly the same, they are given different symbols for convenience of explanation. The optical transceiver of the present invention has a signal level setting function described below,
This eliminates the hassle of setting levels in conventional optical transceivers, making it possible to adjust levels smoothly and in a short time. Referring to FIG. 2, a case will be described in which level adjustment is performed from the optical transceiver 10' to the optical transceiver 10 on the optical transceiver 10 side.

First, the optical transceivers 10 and 10' are connected through the optical fiber 6, and both optical transceivers are turned on. Next, the switch SW3 is turned on to set the optical transceiver 10 to the test mode, and the control signal transmitter 11 sends out a control signal, and the switch SW1 is turned to the test side. The control signal is transmitted via the switch SW1, the optical transmitter 2, the optical splitter 3, and the optical fiber 6, and is further transmitted through the optical splitter 3', the optical receiver 4', and the low-pass filter 13' of the optical transceiver 10'. The signal then reaches the control signal receiving section 12'. Control signal receiving section 1
After 2′ identifies the received signal as a control signal,
Oscillator 15' is driven to generate an output signal and switch SW2' is turned on. The output signal from the oscillator 15' is transmitted via the switch SW2', the optical transmitter 2', the optical branching device 3', and the optical fiber 6 to the optical branching device 3 and the optical receiver 4 of the optical transceiver 10, and then to the level detection unit. Reach 14. The level detection unit 14 detects the transmitted signal and converts it into direct current, and compares the level of the converted signal with a window comparator to see if it is within a predetermined level range. The lamp 16 is turned on. Therefore, by turning the level adjusting variable resistor VR1 of the optical transceiver 10 until the lamp 16 lights up, the signal transmission level of the optical transceiver 10 is set.

Note that the signals injected from the oscillators 15, 15' into the optical transmitters 1, 1' are injected at the same frequency and level as the normally transmitted signals. The same explanation can be given to the case where the level adjustment of the optical transceiver 10' is performed from the optical transceiver 10. In addition, we have explained optical transceivers that transmit analog optical signals using optical fibers.
Naturally, the present invention can also be applied to the case of transmitting analog electrical signals.

As described above, according to the present invention, one person can easily adjust the transmission signal level of an analog signal transmission system that performs bidirectional signal transmission in a short time without the need to separately prepare a signal generator and level meter. Effects that can be set are obtained.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a conventional optical transceiver.
FIG. 2 is a block diagram showing an embodiment of the analog signal transmission system of the present invention. 1, 10, 10′...optical transceiver, 2...optical transmitter,
3... Optical splitter, 4... Optical receiver, 6... Optical fiber,
11, 11'... Control signal transmitter, 12, 12'... Control signal receiver, 13, 13'... Low pass filter,
14, 14'... Level detection section, 15, 15'... Oscillator, 16, 16'... Lamp.

Claims (1)

[Claims] 1. In an analog signal transmission system consisting of a plurality of bidirectional analog signal transceivers that require level adjustment of a transmitted signal before signal transmission, each transceiver transmits a control signal at a predetermined level and frequency. a control signal transmitting means for generating a control signal; a control signal receiving means for determining whether a received signal is a control signal; and a control signal receiving means for generating an output signal of a predetermined level driven by the output from the receiving means in response to reception of the control signal. an oscillator, a level detection means for detecting the level of the output signal, and a level adjustment means for adjusting the control signal until the signal detected by the level detection means reaches a predetermined level; A control signal is sent from the transmitter to the other transceiver, the other oscillator is driven via the control signal receiving means to generate an output signal at a level corresponding to the transmission signal level, and one level detecting means receives the output signal. An analog signal transmission system equipped with a transmission signal level setting function characterized in that the output level of one transmitter/receiver is set to a predetermined signal level by one level adjusting means while detecting the signal. 2. An analog signal transmission system having a transmission signal level setting function according to claim 1, wherein the analog signal receiver comprises an optical transceiver. 3. An analog signal transmission system having a transmission signal level setting function according to claim 1, wherein the frequency and level of the oscillator match the frequency and level of the transmission signal.