CN114760424A - Signal forwarding method, circuit, device and signal distribution testing device - Google Patents

Abstract

The invention provides a signal forwarding method, a circuit, a device and a signal distribution testing device, wherein the signal forwarding method carries out linear compensation on an input analog video signal to realize corresponding compensation and recovery on signal amplitude reduction caused by one-to-multiple-path signal forwarding, meanwhile, the distributed n2 paths of analog video signals are output to a receiving terminal after signal processing, and the drive-by-wire signals reversely transmitted by the receiving terminal are analyzed, meanwhile, the analog video signal is transmitted to a signal transmitting circuit at the later stage and a drive-by-wire signal transmitted reversely at the later stage is received, one receiving terminal only needs to be connected with one signal transmitting circuit and one sending terminal to complete the test, and m receiving terminals only need to be connected with m signal transmitting circuits and one sending terminal to complete the test, so that the test cost is reduced, the test efficiency is improved, and meanwhile, the high-fidelity output of the analog video signal and the reverse transmission of the drive-by-wire signal are realized.

Description

Signal forwarding method, circuit, device and signal distribution test device

technical field

The invention belongs to the technical field of signal processing, and in particular relates to a signal forwarding method, circuit, device and signal distribution testing device.

Background technique

At present, video signals can be divided into digital video signals and analog video signals according to types. For example, a typical analog camera, the output video signal uses analog CVBS (Composite Video Broadcast Signal, composite video broadcast signal) for data transmission.

The CVBS signal has the characteristics of compounding, that is, it combines all the components required to generate a video signal in the same signal. Specifically, the signal is composed of each field serially. Blanking, coaxial line control and other components, the signal of each line also contains components such as line synchronization, color component, luminance component, line blanking and so on.

In the field of development and testing in the field of video surveillance, it is necessary to perform performance testing on the receiving terminal of the analog video signal connected to the corresponding sending terminal. For example, as shown in Figure 1, the DVR is used as the receiving terminal, and a 16-channel DVR is connected as the sending terminal. The 16 analog cameras of the terminal, 16 analog cameras are used as the monitoring front-end to collect real-time video data of their respective monitoring sites, and output analog video signals to be connected to the video ports of the back-end analog high-definition hard disk video recorder for preview monitoring and monitoring of each channel video. video, etc. Among them, analog video signals need to be connected and transmitted one-to-one. In order to ensure accurate test results, operators must set up a sufficient number of cameras in the testing process in the field of equipment research and development and in the production testing and quality inspection process in the field of equipment manufacturing. Access to each video input port of the video recorder.

To connect all the channels of the recorder, 16 cameras need to be set up. Therefore, in the R&D and manufacturing fields, each developer and tester needs to be equipped with 16 cameras, which will occupy more testing resources and office space, especially in the testing process. , this situation is more prominent, the aging test of the equipment prototype usually needs to set up about 10 sets in quantity, so for the 16-channel model, the environment for the aging test needs 160 cameras, and the on-site wiring harness layout is inevitably complicated, so As a result, the test equipment and a large area of the test area are seriously occupied, and the later inspection and maintenance work is time-consuming and labor-intensive, and the operation and maintenance are not convenient and low-efficiency.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a signal forwarding method, which aims to solve the problems of high cost and low efficiency in terminal equipment testing, and at the same time realize high-fidelity signal forwarding.

A first aspect of the embodiments of the present invention provides a signal forwarding method, which is applied to a signal forwarding circuit. A plurality of the signal forwarding circuits are cascaded, and each of the signal forwarding circuits is connected to a receiving terminal. The signal forwarding method includes: :

Acquire the analog video signal output by the sending terminal or the signal forwarding circuit of the previous stage, and obtain and analyze the wire control signal output by the receiving terminal connected at the current stage or obtain the wire control signal output by the signal forwarding circuit of the latter stage;

Perform linear compensation on the analog video signal and distribute it into n1+1 channels, and after signal processing respectively, output the n2 channels of the analog video signal to the n2 signal ports of the receiving terminal connected to this stage and output one channel of the analog video signal. The analog video signal is sent to the signal forwarding circuit of the latter stage, wherein n1≧n2≧2;

The wire control signal is reversely output to the sending terminal or the signal forwarding circuit at the previous stage.

Optionally, the acquiring and parsing the wire-controlled signal output by the receiving terminal connected at the current level specifically includes:

decoding the analog video signal and generating a drive signal;

Identify the field blanking in the analog video signal and generate an enable signal;

The drive signal and the enable signal are superimposed by line control pulses and analyzed to generate the line control signal.

A second aspect of the embodiments of the present invention provides a signal forwarding circuit, including:

Compensation recovery circuit, which is used to connect the sending terminal or the signal forwarding circuit of the previous stage, and obtain the analog video signal output by the sending terminal or the signal forwarding circuit of the preceding stage, and perform signal linearity compensation and distribution For n1+1 way;

n1+1 bidirectional signal transmission circuits that are connected with the output end of the compensation recovery circuit and receive n1+1 analog video signals one by one; wherein,

Among the n1 channels of the bidirectional signal transmission circuits, the n2 channels of the bidirectional signal transmission circuits are connected to the n2 signal ports of the receiving terminal connected to the current stage, and the analog video signals of each channel are processed separately and then output to the n2 channels. sending the analog video signal to the receiving terminal connected at the same level, and acquiring and parsing the wire-controlled signal output by the receiving terminal connected at the same level;

The other channel of the bidirectional signal transmission circuit is used for performing signal processing on the analog video signal output by the compensation recovery circuit and outputting it to the signal forwarding circuit of the subsequent stage, and obtaining the wire control signal output by the signal forwarding circuit of the subsequent stage;

Each of the wire-controlled signals is reversely output to the transmitting terminal through the compensation recovery circuit.

Optionally, each of the bidirectional signal transmission circuits includes:

A first signal transmission circuit, the first end of the first signal transmission circuit is connected to the compensation recovery circuit, and the second end of the first signal transmission circuit is connected to the receiving terminal of the current stage or the signal forwarding of the subsequent stage circuit connection, the first signal transmission circuit is used for performing signal processing on the analog video signal output by the compensation recovery circuit and then outputting it to the receiving terminal of the current stage or the signal forwarding circuit of the subsequent stage;

A second signal transmission circuit, the first end of the second signal transmission circuit is connected to the compensation recovery circuit, and the second end of the second signal transmission circuit is connected to the receiving terminal of the current stage or the signal of the subsequent stage is connected to a forwarding circuit, the second signal transmission circuit is used to analyze the wire-controlled signal output by the receiving terminal connected to the current stage or obtain the wire-controlled signal output by the signal forwarding circuit of the subsequent stage, and reverse the output through the compensation recovery circuit to the sending terminal or the preceding signal forwarding circuit.

Optionally, the first signal transmission circuit includes:

an AC coupling circuit, the AC coupling circuit is connected to the compensation recovery circuit, and couples and outputs the analog video signal;

a filter drive circuit connected to the AC coupling circuit, the filter drive circuit is used for filtering, amplifying and outputting the coupled output analog video signal;

A linear adjustment circuit connected to the filter driving circuit and connected to the receiving terminal of the current stage or the signal forwarding circuit of the subsequent stage, the linear adjustment circuit is used to linearly adjust the filtered and amplified analog video signal, and output An analog video signal with a preset amplitude.

Optionally, the second signal transmission circuit includes:

a wire-controlled decoding circuit connected to the receiving terminal of the current stage or the signal forwarding circuit of the subsequent stage, the wire-controlled decoding circuit is used to analyze the reverse wire-controlled signal in the analog video signal and generate a driving signal;

a vertical blanking synchronization circuit connected to the wire-controlled decoding circuit, the vertical blanking synchronization circuit is used to identify the vertical blanking in the analog video signal and generate an enable signal;

A pulse superposition circuit connected to the line control decoding circuit, the vertical blanking synchronization circuit and the compensation recovery circuit respectively, is used for performing line control pulse superposition on the drive signal and the enable signal and outputting the wire control signal.

Optionally, the signal forwarding circuit further includes:

a first electrostatic protection circuit connected to the front stage of the compensation recovery circuit, the first electrostatic protection circuit is used for electrostatic protection of the input analog video signal or the output wire control signal;

The second electrostatic protection circuit, the first end of the second electrostatic protection circuit is connected to the receiving terminal of the current stage or the signal forwarding circuit of the subsequent stage, and the second end of the second electrostatic protection circuit is respectively connected to the second electrostatic protection circuit. A signal transmission circuit is connected to the second signal transmission circuit, and the second electrostatic protection circuit is used for electrostatic protection for the output analog video signal or the input wire control signal.

Optionally, the signal forwarding circuit further includes:

A power conversion circuit, the power conversion circuit is used for converting and outputting a working power supply of a corresponding voltage size to the bidirectional signal transmission circuit.

A third aspect of the embodiments of the present invention provides a signal forwarding apparatus, including the above-mentioned signal forwarding circuit.

A fourth aspect of the embodiments of the present invention provides a signal distribution test device, including m signal transponders as described above, where m of the signal transponders are cascaded;

The signal forwarding device at the first stage is connected to the sending terminal, and each of the signal forwarding devices is connected to n2 signal ports of the receiving terminal.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the above-mentioned signal forwarding method performs linear compensation on the input analog video signal, so as to realize the corresponding compensation and recovery of the signal amplitude drop caused by the one-to-multiple forwarding of the signal. At the same time, the distributed n2 channels of analog video signals are output to the receiving terminal after signal processing, and analyze the wire control signal reversely transmitted by the receiving terminal. For the transmitted wire-controlled signal, one receiving terminal only needs to connect one signal forwarding circuit and one sending terminal to complete the test, and m receiving terminals only need to connect m signal forwarding circuits and one sending terminal to complete the test, which reduces the test time. cost, improve the test efficiency, and at the same time realize the high-fidelity output of analog video signals and the reverse transmission of wire-controlled signals.

Description of drawings

Fig. 1 is the test schematic diagram of traditional sending terminal and test terminal;

FIG. 2 is a first structural schematic diagram of a signal forwarding circuit provided by an embodiment of the present invention;

3 is a schematic flowchart of a signal forwarding method provided by an embodiment of the present invention;

FIG. 4 is a specific flowchart of step S10 in the signal forwarding method provided by an embodiment of the present invention;

5 is a schematic diagram of a second structure of a signal forwarding circuit provided by an embodiment of the present invention;

FIG. 6 is a third schematic structural diagram of a signal forwarding circuit provided by an embodiment of the present invention;

7 is a schematic diagram of a fourth structure of a signal forwarding circuit provided by an embodiment of the present invention;

FIG. 8 is a fifth structural schematic diagram of a signal forwarding circuit provided by an embodiment of the present invention;

FIG. 9 is a sixth schematic structural diagram of a signal forwarding circuit provided by an embodiment of the present invention;

10 is a schematic circuit diagram of a signal forwarding circuit provided by an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a signal distribution test apparatus provided by an embodiment of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

The first aspect of the embodiments of the present invention proposes a signal forwarding method, which is applied to a signal forwarding circuit 1 . As shown in FIG. 2 , a plurality of signal forwarding circuits 1 are cascaded, and each signal forwarding circuit 1 is connected to a receiving terminal 3 .

Wherein, as shown in FIG. 3 , the signal forwarding method corresponding to the signal forwarding circuit 1 includes:

Step S10: Acquire the analog video signal output by the sending terminal 2 or the previous-stage signal forwarding circuit 1, and obtain and analyze the wire-controlled signal output by the receiving terminal 3 connected at the current stage or obtain the wire-controlled signal output by the downstream signal forwarding circuit 1.

Step S20, perform linear compensation on the analog video signal and distribute it into n1+1 channels, and after signal processing respectively, output n2 channels of analog video signals to the n2 signal ports of the receiving terminal 3 connected at this stage and output one channel of analog video signals to the Post-stage signal forwarding circuit 1, where n1≧n2≧2;

Step S30 , outputting the wire control signal inversely to the sending terminal 2 or the front-stage signal forwarding circuit 1 .

In this embodiment, corresponding to the functions of signal reception, distribution, and forwarding, the signal forwarding circuit 1 is provided with a first port IO1 for connecting the sending terminal 2 or the preceding signal forwarding circuit 1, a second port IO2 for connecting the receiving terminal 3, and a connection The forwarding port IO3 of the post-stage signal forwarding circuit 1 .

The signal forwarding circuit 1 adopts the signal forwarding method to realize the distribution and forwarding of the analog video signal, and at the same time, realize the analysis and reverse output of the wire-controlled signal.

That is, the analog video signal sent by the sending terminal 2 or the analog video signal forwarded and output by the signal forwarding circuit 1 of the previous stage is received through the first port IO1. Principle and composition characteristics, improve the position of the signal forwarding sampling point VA, move forward the star-shaped sampling point VA of the signal forwarding, and set it after linear compensation, the signal amplitude change at the star-shaped sampling point VA is only related to the distribution quantity, that is, It is only related to the number of forwarding channels. At the same time, a corresponding compensation module is set at the star-shaped sampling point VA to realize linear compensation, which realizes the corresponding compensation and recovery of the signal amplitude drop caused by the signal one-to-multiple forwarding, thus realizing the sampling point VA. The signal at the location is fidelity, and since the sampling point VA is moved forward, the compensation parameters of the advance compensation can be flexibly allocated according to the number of forwarding channels, which improves the compatibility.

Among them, the analog video signal is compensated and restored to the original signal at the star sampling point VA, and then distributed to multiple channels. Each channel of analog video signal is optimized by filtering, amplification, linear adjustment, etc. to obtain the expected high-fidelity analog video signal. The signals are respectively output to the n2 signal ports of the sending terminal 2 through the second port IO2, so that the receiving terminal 3 can perform video monitoring or data statistics work.

At the same time, the high-fidelity analog video signal is also forwarded to the rear-stage signal forwarding circuit 1 through the forwarding port IO3, so as to provide the analog video signal to each signal forwarding circuit 1 of the rear-stage, so as to realize the step-by-step forwarding of the analog video signal.

At the same time, the analog video signal is composed of multiple components and is highly composited, which not only includes the forward transmission video signal, but also modulates the wire control signal in the vertical blanking area for reverse transmission. For example, the camera will modulate the reverse wire control signal to CVBS. The field blanking area of the signal is used to complete the reverse control of the video recorder to the analog camera, and realize the functions of on-screen menu display and remote parameter configuration.

Therefore, in order to realize the reverse output of the wire control signal, the signal forwarding method receives and parses the corresponding wire control signal through the second port IO2 or the third port, that is, when the second port IO2 signal is distributed, the control signal forwarding circuit 1 analyzes the current level The connected receiving terminal 3 reversely outputs the line control signal, and at the same time, receives the line control signal output by the rear-stage signal forwarding circuit 1 through the forwarding port IO3, and controls the signal forwarding circuit 1 to perform corresponding signal processing on the line control signal, and then reverse the signal. It is output to the first port IO1, and then output to the transmitting terminal 2 or the signal forwarding circuit 1 of the previous stage.

Wherein, parsing the line control signal in the analog video signal can be specifically realized by a corresponding analysis method. Optionally, as shown in FIG. 4 , acquiring and analyzing the line control signal output by the receiving terminal 3 connected at the same level specifically includes:

Step S11, decoding the analog video signal, and generating a driving signal;

Step S12, identifying the field blanking in the analog video signal, and generating an enabling signal;

Step S13 , superimpose the drive signal and the enable signal by line control pulses, and analyze and generate the line control signal.

In this embodiment, the reversed line control signal in the analog video signal is analyzed by the corresponding decoding module, so as to capture the line control signal from the analog video signal and generate the driving signal. At the same time, the corresponding vertical blanking module is set to complete the analog video signal Midfield blanking identification, generating an enable signal and outputting 123 to provide a working reference for the pulse superposition module. The pulse superposition module completes the wire-controlled pulse superposition of the input signal, so that the wire-controlled signal of the receiving terminal 3 is decoded and synchronized. It is transmitted to the first port IO1 and the sending terminal 2.

By performing linear compensation on the input analog video signal, the corresponding compensation and recovery of the signal amplitude drop caused by one-to-multiple forwarding of the signal is realized. At the same time, the distributed n2 channels of analog video signals are output to the receiving terminal 3 after signal processing, and Analyzing the wire control signal reversely transmitted by the receiving terminal 3, at the same time, forwarding the analog video signal to the signal forwarding circuit 1 of the rear stage and receiving the wire control signal reversely transmitted by the rear stage, one receiving terminal 3 only needs to connect one signal forwarding circuit 1 and one transmitting terminal 2 can complete the test, and m receiving terminals 3 only need to connect m channels of signal forwarding circuit 1 and one transmitting terminal 2 to complete the test, which reduces the test cost, improves the test efficiency, and realizes the analog video. High-fidelity output of signals and reverse transmission of wire-controlled signals.

The internal structure of the signal forwarding circuit 1 can be set correspondingly according to the signal processing, distribution, and forwarding functions, and the specific structure is not limited.

Based on the working principle of the signal forwarding method, as shown in FIG. 5 , a second aspect of the embodiments of the present invention provides a signal forwarding circuit 1, including:

Compensation recovery circuit 200, the compensation recovery circuit 200 is used to connect the sending terminal 2 or the previous stage signal forwarding circuit 1, and obtain the analog video signal output by the sending terminal 2 or the preceding stage signal forwarding circuit 1, and perform signal linear compensation and distribution as n1 +1 way;

The n1+1 bidirectional signal transmission circuit 100 which is connected with the output end of the compensation recovery circuit 200 and receives the n1+1 analog video signals one by one; wherein,

The n2 channels of bidirectional signal transmission circuits 100 in the n1 channels of bidirectional signal transmission circuits 100 are connected to the n2 signal ports of the receiving terminal 3 connected to the same stage, and perform signal processing on each channel of analog video signals respectively, and then output the n2 channels of analog video signals to The receiving terminal 3 connected at the same level, and acquiring and parsing the wire control signal output by the receiving terminal 3 connected at the same level;

The other bidirectional signal transmission circuit 100 is used for performing signal processing on the analog video signal output by the compensation recovery circuit 200 and outputting it to the rear-stage signal forwarding circuit 1, and obtaining the wire-controlled signal output by the rear-stage signal forwarding circuit 1;

Each wire control signal is reversely output to the sending terminal 2 through the compensation recovery circuit 200 .

In this embodiment, the signal forwarding circuit 1 realizes one-to-many distribution and forwarding functions, realizes high-fidelity forwarding of analog video signals, and reverse output of wire-controlled signals, corresponding to the functions of signal reception, distribution, and forwarding, the signal forwarding circuit 1 A first port IO1 for connecting the sending terminal 2 or the previous stage signal forwarding circuit 1 is provided, a second port IO2 for connecting the receiving terminal 3 and a forwarding port IO3 for connecting with the subsequent stage signal forwarding circuit 1 .

The signal forwarding circuit 1 adopts the signal forwarding method to realize the distribution and forwarding of the analog video signal, and at the same time, realize the analysis and reverse output of the wire-controlled signal.

That is, the analog video signal sent by the sending terminal 2 or the analog video signal forwarded and output by the signal forwarding circuit 1 of the previous stage is received through the first port IO1. The principle and structural characteristics improve the position of the signal forwarding sampling point VA, move the star-shaped sampling point VA forwarded by the signal forwarding, and set it after the compensation recovery circuit 200, the signal amplitude change at the star-shaped sampling point VA is only related to the distribution quantity. , that is, it is only related to the number of forwarding channels. At the same time, a corresponding compensation recovery circuit 200 is set at the star-shaped sampling point VA to realize linear compensation, so as to realize the corresponding compensation and recovery of the signal amplitude drop caused by the one-to-multiple forwarding of the signal, so as to realize The signal fidelity at the sampling point VA is improved, and since the sampling point VA is moved forward, the compensation parameters of the compensation recovery circuit 200 can be flexibly allocated according to the number of forwarding channels, which improves the compatibility.

Among them, after the analog video signal is compensated and restored to the original signal at the star-shaped sampling point VA, it is distributed to multiple channels. Each channel of analog video signal is optimized by filtering, amplifying, and linear adjustment by each bidirectional signal transmission circuit 100 to obtain the expected high-definition signal. The real analog video signal is output to the n2 signal ports of the sending terminal 2 through the second port IO2 respectively, so that the receiving terminal 3 can perform video monitoring or data statistics work.

At the same time, the high-fidelity analog video signal is also forwarded to the rear-stage signal forwarding circuit 1 through the forwarding port IO3 of a two-way signal transmission circuit 100 to provide the analog video signal to each signal forwarding circuit 1 of the rear-stage, so as to realize the step-by-step forwarding of the analog video signal. , so that during the test, multiple receiving terminals 3 are matched with one sending terminal 2 and multiple signal forwarding circuits 1 to complete the performance test, which reduces the test cost and improves the test efficiency.

At the same time, the analog video signal is composed of multiple components and is highly composited, which not only includes the forward transmission video signal, but also modulates the wire control signal in the vertical blanking area for reverse transmission. For example, the camera will modulate the reverse wire control signal to CVBS. The field blanking area of the signal is used to complete the reverse control of the video recorder to the analog camera, and realize the functions of on-screen menu display and remote parameter configuration.

Therefore, in order to realize the reverse output of the wire control signal, the bidirectional signal transmission circuit 100 receives and analyzes the corresponding wire control signal through the second port IO2 or the third port, that is, when the second port IO2 signal is distributed, the bidirectional signal transmission circuit 100 analyzes The wire-controlled signal output by the receiving terminal 3 connected at this stage is reversely output. At the same time, it receives the wire-controlled signal output by the rear-stage signal forwarding circuit 1 through the forwarding port IO3. The first port IO1 is further output to the sending terminal 2 or the signal forwarding circuit 1 of the previous stage, and finally realizes the reverse control of the sending terminal 2, and completes operations such as parameter configuration and zoom control.

Among them, one signal forwarding circuit 1 can be connected to at least one receiving terminal 3, and can match and connect different types of receiving terminals 3 with signal ports P1 to Pn2 ranging from 2 to n1, which improves the test compatibility. The number of the two-port IO2 and the bidirectional signal transmission circuit 100 can be correspondingly set according to the receiving terminal 3 .

The analog video signal is input from one channel and then forwarded by multiple channels, the input impedance at the star sampling point VA will become smaller, causing the signal amplitude to decrease accordingly. The compensation recovery circuit 200 is used to compensate for the decrease in the input impedance at the star sampling point VA. It can perform linear compensation for the amplitude of the input signal. Optionally, the compensation recovery circuit 200 is composed of resistors. The number of distribution channels and the model of the filter driver U1 are different, and the input impedance at the star sampling point VA will be different accordingly. , Optionally, as shown in FIG. 10 , the compensation recovery circuit 200 includes a second resistor R2 and a third resistor R3 connected in series.

The specific structure of the bidirectional signal transmission circuit 100 can be correspondingly set according to the signal processing requirements of the analog video signal and the wire-controlled signal, and a compensation circuit, a decoding circuit, etc. can be set correspondingly, and the specific structure is not limited.

As shown in FIG. 6, optionally, each bidirectional signal transmission circuit 100 includes:

The first signal transmission circuit 110, the first end of the first signal transmission circuit 110 is connected to the compensation recovery circuit 200, the second end of the first signal transmission circuit 110 is connected to the receiving terminal 3 of the current stage or the signal forwarding circuit 1 of the latter stage, A signal transmission circuit 110 is used for performing signal processing on the analog video signal output by the compensation recovery circuit 200 and outputting it to the receiving terminal 3 of the current stage or the signal forwarding circuit 1 of the subsequent stage;

The second signal transmission circuit 120, the first end of the second signal transmission circuit 120 is connected to the compensation recovery circuit 200, the second end of the second signal transmission circuit 120 is connected to the receiving terminal 3 of the current stage or the signal forwarding circuit 1 of the subsequent stage, The second signal transmission circuit 120 is used to analyze the line control signal output by the receiving terminal 3 connected to the current stage or obtain the line control signal output by the signal forwarding circuit 1 of the subsequent stage, and reversely output it to the sending terminal 2 or the previous stage through the compensation recovery circuit 200 Stage signal forwarding circuit 1.

In this embodiment, the first signal transmission circuit 110 completes the forward distribution of the analog video signal, the second signal transmission circuit 120 implements the reverse transmission of the wire-controlled signal, and the first signal transmission circuit 110 completes the filtering and amplification of the analog signal , linear adjustment and other signal processing, so as to achieve the maximum fidelity of the video signal, the second signal transmission circuit 120 completes the analog video signal line control decoding, vertical blanking synchronization, pulse superposition and other operations, so as to realize the line control signal return to the transmission Terminal 2.

The first signal transmission circuit 110 and the second signal transmission circuit 120 are specifically set according to the forward signal distribution function and the reverse transmission function of the wire control signal, and the specific structures are not limited.

As shown in FIG. 7 , optionally, the first signal transmission circuit 110 includes:

AC coupling circuit 111, the AC coupling circuit 111 is connected to the compensation recovery circuit 200, and outputs the analog video signal by coupling;

A filter drive circuit 112 connected to the AC coupling circuit 111, and the filter drive circuit 112 is used to filter and amplify the coupled output analog video signal and output it;

A linear adjustment circuit 113 connected to the filter driving circuit 112 and connected to the receiving terminal 3 of the current stage or the signal forwarding circuit 1 of the subsequent stage, the linear adjustment circuit 113 is used to linearly adjust the filtered and amplified analog video signal, and output a preset amplitude value of the analog video signal.

In this embodiment, the AC coupling circuit 111 is used to realize the coupling and output of the analog video signal, and cooperate with the filter driving circuit 112 to obtain low noise performance. As shown in FIG. 8 , optionally, the AC coupling circuit 111 includes a capacitor C1 and the capacitor C1 It is connected in series between the first port IO1 and the filter driving circuit 112 .

The filter driving circuit 112 filters the high-frequency noise introduced by the power supply, lines, cables, etc. on the output signal of the AC coupling circuit 111, and on the other hand completes the signal amplification. The linear adjustment circuit 113 adapts the amplification capability of the filter driving circuit 112, Linearly adjust the composite video signal to a preset size, wherein, as shown in FIG. 10 , the filter driver circuit 112 includes a filter driver U1, and the linear adjustment circuit 113 includes a first resistor R1, which is connected in series between the filter driver U1 and the first resistor R1. Between two port IO2 or forwarding port IO3.

At the same time, the filter driver U1 of the corresponding model is selected according to the type and resolution of the analog video signal, the value of the capacitor C1 of the AC coupling circuit 111 is selected according to the coupling bandwidth of the filter driver U1, the first resistor R1 is selected according to the amplification factor of the filter driver U1, and The resistance value of the first resistor R1 and the capacitance value of the capacitor C1 are adjusted correspondingly, so that the amplitudes of the input signal of the filter driver U1 and the output signal of the linear adjustment circuit 113 are close to each other.

Meanwhile, as shown in FIG. 7 , optionally, the second signal transmission circuit 120 includes:

The second signal transmission circuit 120 includes:

The wire-controlled decoding circuit 121 connected to the current-stage receiving terminal 3 or the subsequent-stage signal forwarding circuit 1, and the wire-controlled decoding circuit 121 are used to analyze the reverse wire-controlled signal in the analog video signal, and generate a driving signal;

The vertical blanking synchronization circuit 122 connected with the wire-controlled decoding circuit 121, and the vertical blanking synchronization circuit 122, are used to identify the vertical blanking in the analog video signal and generate an enable signal;

The pulse superposition circuit 123, which is respectively connected to the line control decoding circuit 121, the vertical blanking synchronization circuit 122 and the compensation recovery circuit 200, is used to perform line control pulse superposition on the drive signal and the enable signal and output the line control signal.

In this embodiment, in order to analyze the reversed line control signal in the analog video signal, a line control decoding circuit 121 is added. The line control decoding circuit 121 captures the line control signal from the analog video signal, generates a driving signal and outputs it to the pulse superposition circuit 123. Optionally, as shown in FIG. 10, the wire-controlled decoding circuit 121 is composed of a single-channel high-speed comparator U3.

Specifically, since the reverse wire control signal is several groups of pulse periodic waves in the vertical blanking area, the level amplitude is usually designed to be around 1V. Set at 800mV, the output signal is connected to the positive input terminal of the comparator U3.

The vertical blanking synchronization circuit 122 completes the identification of the vertical blanking in the analog video signal, generates an enable signal and outputs it to the pulse superposition circuit 123, and provides a working reference for the pulse superposition circuit 123. Optionally, the vertical blanking synchronization circuit 122 is composed of a single The high-speed comparator U3 of the channel is formed, that is, the high-speed comparator U3 completes the decoding of the line control signal and the signal conversion of the vertical blanking synchronization.

Specifically, since the level amplitude of the vertical blanking signal is 300mV, the reference voltage V2 of the comparator U3 of the vertical blanking synchronization circuit 122 needs to be set higher than 300mV. Optionally, the reference voltage V2 is set to 330mV.

The pulse superposition circuit 123 completes the wire-controlled pulse superposition of the input signal, so that the wire-controlled signal of the receiving terminal 3 is decoded and synchronized, and then reversely transmitted to the first port IO1 and the sending terminal 2, optionally, as shown in FIG. 10 . , the pulse superposition circuit 123 is composed of an analog switch U2, an NPN transistor Q1 and a sixth resistor R6.

As shown in FIG. 8, optionally, the signal forwarding circuit 1 further includes:

The first electrostatic protection circuit 300 connected to the front stage of the compensation recovery circuit 200, the first electrostatic protection circuit 300 is used for electrostatic protection for the input analog video signal or the output wire control signal;

The second electrostatic protection circuit 400, the first end of the second electrostatic protection circuit 400 is connected to the receiving terminal 3 of the current stage or the signal forwarding circuit 1 of the subsequent stage, and the second end of the second electrostatic protection circuit 400 is respectively connected to the first signal transmission circuit 110 Connected to the second signal transmission circuit 120, the second electrostatic protection circuit 400 is used for electrostatic protection for the output analog video signal or the input wire control signal.

In this embodiment, the first electrostatic protection circuit 300 and the second electrostatic protection circuit 400 are used to perform electrostatic protection on the corresponding ports, and prevent the circuit from being damaged due to the entry of external static electricity through electrostatic discharge introduced to the ports. The electrostatic protection circuits are distributed in For the input end and output end of the signal forwarding circuit 1, the electrostatic protection circuit can choose a one-way TVS tube, or other types of protection devices.

As shown in FIG. 9, optionally, the signal forwarding circuit 1 further includes:

The power conversion circuit 500 , the power conversion circuit 500 , is used for converting and outputting the working power of the corresponding voltage to the bidirectional signal transmission circuit 100 .

In this embodiment, the power conversion circuit 500 obtains external power through the power port IO4 and converts and outputs at least one working power to each circuit inside the signal forwarding circuit 1, so that the internal circuit can perform corresponding signal processing and transmission operations.

The power conversion circuit 500 may adopt structures such as a buck-boost circuit, a voltage regulator circuit, and a DC/DC conversion circuit, and the specific structure is not limited.

At the same time, the power conversion circuit 500 can also be equipped with a corresponding filter circuit to realize the plane filtering function. The filter circuit can be composed of a chip ceramic capacitor. The capacitance value of the chip ceramic capacitor depends on the power conversion circuit 500 and the filter driver U1. Comprehensive selection, the specific size is not limited.

The present invention also provides a signal repeating device 1000. As shown in FIG. 11, the signal repeating device 1000 includes a signal repeating device 1000. The specific structure of the signal repeating device 1000 refers to the above-mentioned embodiment. All the technical solutions of all the embodiments have at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here.

In this embodiment, the first port IO1, the second port IO2 and the forwarding port IO3 are integrated on the signal forwarding device 1000, and a corresponding port structure is used to connect the sending terminal 2, the receiving terminal 3 and the subsequent signal forwarding device 1000. Each circuit in the forwarding circuit 1 is arranged on the circuit board of the signal forwarding device 1000, and is electrically connected with the corresponding port to realize the sending and receiving of analog video signals and wire-controlled signals.

At the same time, when the signal transponder 1000 is used to test the receiving terminal 3, one receiving terminal 3 only needs to connect one signal transponder 1000 and one transmitting terminal 2 to complete the test, and m receiving terminals 3 only need to connect m channels of signal transponders. 1000 and one sending terminal 2 can complete the test, which reduces the test cost and improves the test efficiency.

The present invention also provides a signal distribution test device, the signal distribution test device includes m signal transponders 1000, the specific structure of the signal transponder 1000 refers to the above-mentioned embodiment, because the signal distribution and test device adopts all the above-mentioned embodiments. All technical solutions, therefore at least have all the beneficial effects brought by the technical solutions of the above embodiments, and will not be repeated here. Wherein, m signal transponders 1000 are cascaded;

The signal forwarding device 1000 at the first stage is connected to the transmitting terminal 2 , and each signal forwarding device 1000 is connected to n2 signal ports P1 - Pn2 of the receiving terminal 3 .

In this embodiment, the signal transponders 1000 are cascaded to form a signal distribution test device, which forms a one-to-many connection between a sending terminal 2 and a plurality of receiving terminals 3 and a signal distribution operation. At the same time, a sending terminal 2 is used to form a test device to realize a one-to-many connection. For the synchronization test of the number of receiving terminals 3, the m receiving terminals 3 only need to connect m channels of signal transponders 1000 and one transmitting terminal 2 to complete the test, which reduces the test cost and improves the test efficiency. At the same time, each receiving terminal 3 also The line control signal can be sent to the sending terminal 2 through the corresponding signal forwarding device 1000 to realize many-to-one time-sharing control.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is still possible to implement the foregoing implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the within the protection scope of the present invention.

Claims (10)

1. A signal forwarding method is applied to a signal forwarding circuit, and is characterized in that a plurality of signal forwarding circuits are cascaded, each signal forwarding circuit is connected with a receiving terminal, and the signal forwarding method comprises the following steps:

acquiring an analog video signal output by a sending terminal or a front-stage signal forwarding circuit, and acquiring and analyzing a line control signal output by a receiving terminal connected with the front-stage signal forwarding circuit or acquiring a line control signal output by a rear-stage signal forwarding circuit;

performing linear compensation on the analog video signals, distributing the analog video signals into n1+1 paths, respectively performing signal processing, and outputting n2 paths of the analog video signals to n2 signal ports of the receiving terminal connected to the current stage and outputting one path of the analog video signals to the signal forwarding circuit connected to the subsequent stage, wherein n1 ≧ n2 ≧ 2;

and reversely outputting the line control signal to the sending terminal or the front stage of the signal forwarding circuit.

2. The signal forwarding method according to claim 1, wherein the acquiring and analyzing the line control signal output by the receiving terminal connected to the current stage specifically comprises:

decoding the analog video signal and generating a driving signal;

identifying the vertical blanking in the analog video signal and generating an enabling signal;

and performing line control pulse superposition on the driving signal and the enabling signal and analyzing to generate the line control signal.

3. A signal repeating circuit, comprising:

the compensation recovery circuit is used for connecting a sending terminal or a preceding-stage signal forwarding circuit, acquiring an analog video signal output by the sending terminal or the preceding-stage signal forwarding circuit, and performing linear compensation and distribution on the signal into n1+1 paths;

the n1+1 paths of bidirectional signal transmission circuits are connected with the output end of the compensation recovery circuit in common and receive the n1+1 paths of analog video signals one by one; wherein,

n1 paths of the bidirectional signal transmission circuit, wherein n2 paths of the bidirectional signal transmission circuit are connected with n2 signal ports of a receiving terminal connected with the stage, and after performing signal processing on each path of the analog video signal, n2 paths of the analog video signal are output to the receiving terminal connected with the stage, and a line control signal output by the receiving terminal connected with the stage is obtained and analyzed;

the other two-way signal transmission circuit is used for performing signal processing on the analog video signal output by the compensation recovery circuit, outputting the analog video signal to the post-stage signal forwarding circuit and acquiring a line control signal output by the post-stage signal forwarding circuit;

and each line control signal is reversely output to the sending terminal through the compensation recovery circuit.

4. The signal repeating circuit of claim 3, wherein each of said bidirectional signal transmitting circuits comprises:

a first signal transmission circuit, a first end of which is connected to the compensation recovery circuit, a second end of which is connected to the receiving terminal of the current stage or the signal forwarding circuit of the next stage, and the first signal transmission circuit is configured to perform signal processing on the analog video signal output by the compensation recovery circuit and output the processed analog video signal to the receiving terminal of the current stage or the signal forwarding circuit of the next stage;

and the first end of the second signal transmission circuit is connected with the compensation recovery circuit, the second end of the second signal transmission circuit is connected with the receiving terminal or the post-stage signal forwarding circuit, and the second signal transmission circuit is used for analyzing the drive-by-wire signal output by the receiving terminal connected with the current stage or acquiring the drive-by-wire signal output by the post-stage signal forwarding circuit, and reversely outputting the drive-by-wire signal to the sending terminal or the pre-stage signal forwarding circuit through the compensation recovery circuit.

5. The signal repeating circuit of claim 4, wherein the first signal transmission circuit comprises:

the alternating current coupling circuit is connected with the compensation recovery circuit and is used for coupling and outputting the analog video signal;

the filtering driving circuit is connected with the alternating current coupling circuit and is used for filtering, amplifying and outputting the coupled and output analog video signals;

and the linear adjusting circuit is connected with the filtering driving circuit and the receiving terminal or the signal forwarding circuit at the current stage, and is used for linearly adjusting the filtered and amplified analog video signal and outputting the analog video signal with a preset amplitude.

6. The signal forwarding circuit of claim 4, wherein the second signal transmission circuit comprises:

the drive-by-wire decoding circuit is connected with the receiving terminal at the current stage or the signal forwarding circuit at the later stage and is used for analyzing the reverse drive-by-wire signal in the analog video signal and generating a driving signal;

the vertical blanking synchronous circuit is connected with the line control decoding circuit and is used for identifying vertical blanking in the analog video signal and generating an enabling signal;

and the pulse superposition circuit is respectively connected with the drive-by-wire decoding circuit, the field blanking synchronous circuit and the compensation recovery circuit and is used for carrying out drive-by-wire pulse superposition on the drive signal and the enable signal and outputting the drive-by-wire signal.

7. The signal repeating circuit of claim 4, wherein the signal repeating circuit further comprises:

the first electrostatic protection circuit is connected to the front stage of the compensation recovery circuit and is used for performing electrostatic protection on an input analog video signal or an output drive-by-wire signal;

and a first end of the second electrostatic protection circuit is connected with the receiving terminal or the post-stage signal forwarding circuit, a second end of the second electrostatic protection circuit is respectively connected with the first signal transmission circuit and the second signal transmission circuit, and the second electrostatic protection circuit is used for performing electrostatic protection on the output analog video signal or the input drive-by-wire signal.

8. The signal repeating circuit of claim 3, wherein the signal repeating circuit further comprises:

and the power supply conversion circuit is used for converting and outputting a working power supply with a corresponding voltage to the bidirectional signal transmission circuit.

9. A signal transfer apparatus comprising a signal transfer circuit according to any one of claims 3 to 8.

10. A signal distribution test apparatus comprising m signal forwarding apparatuses according to claim 9, wherein m signal forwarding apparatuses are arranged in cascade, and m ≧ 2;

the signal forwarding devices at the first stage are connected with the sending terminal, and each signal forwarding device is connected with n2 signal ports of the receiving terminal.

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