CN104749974B - A kind of method and device for obtaining comparison voltage signal and extracting reverse control signal - Google Patents
A kind of method and device for obtaining comparison voltage signal and extracting reverse control signal Download PDFInfo
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- CN104749974B CN104749974B CN201310753463.0A CN201310753463A CN104749974B CN 104749974 B CN104749974 B CN 104749974B CN 201310753463 A CN201310753463 A CN 201310753463A CN 104749974 B CN104749974 B CN 104749974B
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
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Abstract
The invention discloses a kind of method and device for obtaining comparison voltage signal and extracting reverse control signal, to solve over long distances caused by transmission the problem of reverse control signal time domain mechanical periodicity.Obtaining comparison voltage recoil simulator includes：Maximum level acquisition module is used for the maximum level for detecting that cable uploads defeated signal；The maximum level that comparison voltage acquisition module is used to be detected according to maximum level acquisition module obtains comparison voltage, and be compared the comparison voltage and reference comparison voltages, obtain wherein maximum and be used as optimal comparison voltage, the optimal comparison voltage is used to extract the reverse control signal in the signal transmitted on the cable, the comparison voltage and the relation character of the maximum level close the long range transfer function for stating cable, the reference comparison voltages are more than the multimedia data signal in the signal transmitted on the cable, and less than limit comparison voltage, the limit comparison voltage meets long range transfer function with the maximum level that cable is exported in limiting length.
Description
Technical field
The present invention relates to field of multimedia data transmission, more particularly to a kind of acquisition comparison voltage signal and extraction reversely control
The method and device of signal processed.
Background technology
In existing multi-medium data transmission technology, two kinds of data are transmitted generally in same cable, one is positive
Transmit data（That is multimedia data signal）, another is reverse control signal.Prior art is folded using amplitude in transmission
Plus mode, i.e., reverse control signal is directly superimposed upon with more than the amplitude of multimedia data signal with multimedia data signal
Transmitted in same cable, then in controlled end（Such as analogue camera）, by amplitude comparator, reverse control signal from cable
Extracted in the signal of transmission.Exactly because the amplitude of reverse control signal is more than multimedia data signal, so existing skill
The method for extracting signal used in art is：Medium voltage of the setting one between multimedia data signal and reverse control signal is made
For the comparison voltage of amplitude comparator, by the way that the signal transmitted on cable is made comparisons with the medium voltage of the setting, so as to carry
Reverse control signal is taken out.
But, with increasing for the large-range monitoring demand such as highway, safe city, controlled end and control end（For example
Back-end processing device）The distance between it is more and more remote, signal attenuation can be caused.For reverse control signal, belong to serial ports
This kind of asynchronous control signal, this signal is very high for time domain critical in itself, and its time domain cycle varies slightly being likely to lead
Data are caused not recognize correctly, so as to limit the length limit of cable.
Reverse control signal is after the cable transmission by certain distance, it may occur that following two changes, and one kind is voltage
Changes in amplitude（Diminish）, another is the change of signal edge（Slow down）, both change can all cause reverse control signal when
Change on the cycle of domain.
With reference to above-mentioned reverse control signal extracting method of the prior art, illustrate two kinds of changes to reversely control separately below
What signal processed was extracted directly affects.
First, voltage amplitude variation：
As shown in figure 1, VDD1 represents the amplitude of original reverse control signal, Vref is the comparison for extracting reverse control signal
Voltage, VDD2 is signal amplitude of the reverse control signal after long-distance transmissions decay（VDD2<VDD1）.Can from Fig. 1
Go out, if primary signal does not compare with Vref directly through overdamping, the signal time domain cycle T 1 recovered, but if by
After transmitting over long distances, signal can decay, the amplitude of signal may diminish, and be compressed equivalent to signal.If after decaying
Signal it is same compare with Vref, the time domain cycle of the reverse control signal recovered will shorten to T2, so result in
Change of the signal on the time domain cycle.
Secondly, signal edge change：
As shown in Fig. 2 here premised on the constant ideal conditions of amplitude, it is simple to assume that reverse control signal is edge
Slow down.It, in positive exponent change, is in negative exponent change, so the rising edge of signal is with in trailing edge to be due to signal rising edge
Drop is along in the corresponding slope of voltage identical point being different, although rising edge and trailing edge slow down, it is caused on
Rise along comparing delay, and trailing edge compare postpone it is different, so as to cause the reverse control signal recovered in the time domain cycle
On change.
The content of the invention
The embodiment of the present invention provides a kind of method and device for obtaining comparison voltage signal and extracting reverse control signal, with
Solve the problem of existing long range transmits caused reverse control signal time domain mechanical periodicity.
The embodiment of the present invention provides a kind of device for obtaining comparison voltage signal, and the device includes：
Maximum level acquisition module, for detecting that cable uploads the maximum level of defeated signal；
Comparison voltage acquisition module, the maximum level for being detected according to maximum level acquisition module obtains more electric
Pressure, and the comparison voltage and reference comparison voltages are compared, wherein maximum is as optimal comparison voltage for acquisition, and this is optimal
Comparison voltage is used to extract the reverse control signal in the signal transmitted on the cable, the comparison voltage and the maximum level
Relation character close the long range transfer function for stating cable, the reference comparison voltages are more than in the signal transmitted on the cable
Multimedia data signal, and the highest exported less than limit comparison voltage, the limit comparison voltage with cable in limiting length
Level meets long range transfer function.
Using said apparatus, the maximum level of the signal transmitted on the cable detected by maximum level acquisition module,
Comparison voltage, and comparison voltage and the maximum level are obtained according to above-mentioned maximum level by comparison voltage acquisition module again
The long range transfer function of relation character zygonema cable, so as to ensure that the time domain cycle of reverse control signal is not when long range is transmitted
Become, it is to avoid the amplitude and edge of voltage change the influence to reverse control signal caused by length of cable, and then add line
The upper limit of cable length.Above-mentioned reference comparison voltages are set greater than the multimedia data signal in the signal, it is ensured that cable
The multimedia data signal of upper transmission will not be compared for reverse control signal by mistake.
Preferably, above-mentioned maximum level acquisition module is peak detection module.
Preferably, above-mentioned comparison voltage acquisition module can include but are not limited to following two implementations：
The first implementation, the comparison voltage acquisition module includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum conduct
Optimal comparison voltage.
Second of implementation, the comparison voltage acquisition module includes division module, constant voltage source, the first one-way conduction
Switch and the second unidirectional conducting switch：
Division module is used to obtain the comparison voltage；
Constant voltage source is used to provide the reference comparison voltages；
When comparison voltage is more than reference comparison voltages, the first unidirectional conducting switch conducting, second unidirectional conducting switch is cut
Only, division module output comparison voltage is used as the optimal comparison voltage；
When comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, first one-way conduction is opened
Cut-off is closed, constant voltage source output reference comparison voltages are used as the optimal comparison voltage.
The embodiment of the present invention additionally provides a kind of method for obtaining comparison voltage signal, and this method includes：
Detect the maximum level of the signal transmitted on cable；
Comparison voltage is obtained according to the maximum level detected；
Comparison voltage is compared with reference comparison voltages, and obtains wherein maximum as optimal comparison voltage, should
Comparison voltage and the relation of the maximum level meet the long range transfer function of the cable, and the reference comparison voltages are more than institute
State the multimedia data signal in the signal transmitted on cable.
Using the above method, pass through the maximum level of the signal transmitted on the cable that is transmitted on the cable that detects, then root
Comparison voltage is obtained according to above-mentioned maximum level, and comparison voltage and the long range of the relation character zygonema cable of the maximum level are transmitted
Function, so as to ensure that the time domain cycle of reverse control signal is constant when long range is transmitted, it is to avoid electricity caused by length of cable
The amplitude and edge of pressure change the influence to reverse control signal, and then add the upper limit of length of cable.Above-mentioned reference is compared
Voltage is set greater than the multimedia data signal in the signal, it is ensured that the multimedia data signal transmitted on cable will not
Compared by mistake for reverse control signal.
The embodiment of the present invention additionally provides a kind of reverse control signal extraction element, and the device includes：
Maximum level acquisition module, for detecting that cable uploads the maximum level of defeated signal；
Comparison voltage acquisition module, the maximum level for being detected according to maximum level acquisition module obtains more electric
Pressure, and the comparison voltage and reference comparison voltages are compared, wherein maximum is as optimal comparison voltage for acquisition, and this compares
The relation character of voltage and the maximum level closes the long range transfer function for stating cable, and the reference comparison voltages are more than the line
Multimedia data signal in the signal transmitted on cable, and less than limit comparison voltage, the limit comparison voltage and the line
The maximum level that cable is exported in limiting length meets long range transfer function；
Voltage comparison module, for the signal transmitted on cable to be compared with above-mentioned optimal comparison voltage, so as to carry
Reverse control signal in the signal transmitted on line taking cable.
The maximum level of the signal transmitted on the cable detected by maximum level acquisition module, then pass through comparison voltage
Acquisition module obtains comparison voltage according to above-mentioned maximum level, will be transmitted using voltage comparison module on the cable transmitted on cable
Signal be compared with optimal comparison voltage, so as to extract the reverse control signal in the signal transmitted on cable, and compare
The long range transfer function of voltage and the relation character zygonema cable of the maximum level.Utilize said apparatus, it is ensured that pass in long range
When defeated, the time domain cycle of reverse control signal is constant, it is to avoid the amplitude and edge of voltage change to anti-caused by length of cable
To the influence of control signal, and then add the upper limit of length of cable.Above-mentioned reference comparison voltages are set greater than the signal
In multimedia data signal, it is ensured that the multimedia data signal transmitted on cable will not be compared by mistake for Reverse Turning Control believe
Number.
Preferably, above-mentioned maximum level acquisition module is peak detection module.
Preferably, above-mentioned comparison voltage acquisition module can include but are not limited to following two implementations：
The first implementation, the comparison voltage acquisition module includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum conduct
Optimal comparison voltage.
Second of implementation, the comparison voltage acquisition module includes division module, constant voltage source, the first one-way conduction
Switch and the second unidirectional conducting switch：
Division module is used to obtain the comparison voltage；
Constant voltage source is used to provide the reference comparison voltages；
When comparison voltage is more than reference comparison voltages, the first unidirectional conducting switch conducting, second unidirectional conducting switch is cut
Only, division module output comparison voltage is used as optimal comparison voltage；
When comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, first one-way conduction is opened
Cut-off is closed, constant voltage source output reference comparison voltages are used as optimal comparison voltage.
The embodiment of the present invention additionally provides a kind of reverse control signal extracting method, and this method includes：
Detect the maximum level of the signal transmitted on cable；
Comparison voltage is obtained according to the maximum level detected；
Comparison voltage is compared with reference comparison voltages, and obtains wherein maximum as optimal comparison voltage, should
The relation character of comparison voltage and above-mentioned maximum level closes the long range transfer function for stating cable, and the reference comparison voltages are more than line
Multimedia data signal in the signal transmitted on cable, and less than limit comparison voltage, the limit comparison voltage is with cable in pole
The maximum level exported when limit for length spends meets long range transfer function.
Above-mentioned optimal comparison voltage and the signal that is transmitted on cable are compared, so as to extract the signal transmitted on cable
In reverse control signal.
By the maximum level of the signal transmitted on the cable that detects, obtain more electric further according to above-mentioned maximum level
Pressure, the signal transmitted on cable is compared with optimal reference comparison voltage, so as to extract in the signal transmitted on cable
Reverse control signal, and comparison voltage and the long range transfer function of the relation character zygonema cable of the maximum level.Using above-mentioned
Method, it is ensured that when long range is transmitted, the time domain cycle of reverse control signal is constant, it is to avoid voltage caused by length of cable
Amplitude and edge change the influence to reverse control signal, and then add the upper limit of length of cable.Above-mentioned reference comparison voltages
It is set greater than the multimedia data signal in the signal, it is ensured that the multimedia data signal transmitted on cable will not be missed
Compare for reverse control signal.
Brief description of the drawings
Fig. 1 is time domain change schematic diagram caused by change of the reverse control signal on level in the prior art；
Fig. 2 is time domain change schematic diagram caused by change of the reverse control signal on edge in the prior art；
Fig. 3 is the schematic device provided in an embodiment of the present invention for obtaining comparison voltage signal；
Fig. 4 is the method flow diagram provided in an embodiment of the present invention for obtaining comparison voltage signal；
Fig. 5 is the schematic device provided in an embodiment of the present invention for extracting reverse control signal；
Fig. 6 is the method flow diagram provided in an embodiment of the present invention for extracting reverse control signal；
Fig. 7 is the capacitor charging circuit schematic diagram of the embodiment of the present invention；
Fig. 8 is the capacitor discharging circuit schematic diagram of the embodiment of the present invention；
Fig. 9 is the circuit diagram provided in an embodiment of the present invention for extracting reverse control signal；
Figure 10 voltage oscillograms that each is put for the circuit provided in an embodiment of the present invention for extracting reverse control signal.
Embodiment
The embodiment of the present invention provides a kind of method and device for obtaining comparison voltage signal and extracting reverse control signal, with
The problem of reverse control signal caused by solving the transmission of prior art middle and long distance changes in time domain.
Embodiments of the present invention is further illustrated below in conjunction with the accompanying drawings.
The embodiments of the invention provide a kind of device for obtaining comparison voltage signal, as shown in figure 3, the device includes：
Maximum level acquisition module 301, for detecting that cable uploads the maximum level of defeated signal；
Preferably, the maximum level acquisition module 301 is peak detection module.
Comparison voltage acquisition module 302, the maximum level for being detected according to maximum level acquisition module 301, which is obtained, to be compared
It is compared compared with voltage, and by the comparison voltage and reference comparison voltages, obtains wherein maximum as optimal comparison voltage, should
Optimal comparison voltage is used to extract the reverse control signal in the signal transmitted on the cable, the comparison voltage and the highest
The relation character of level closes the long range transfer function for stating cable, and the reference comparison voltages are more than the signal transmitted on the cable
In multimedia data signal, and less than limit comparison voltage, what the limit comparison voltage was exported with cable in limiting length
Maximum level meets long range transfer function.
The limiting length of so-called cable refers to the cable in actual applications, accessible maximum length.The limit of cable
Length generally counts by production firm, tests and obtains.
The long range transfer function of the cable can be capacitor charge and discharge pattern function etc..
Preferably, the comparison voltage acquisition module 302 can include but are not limited to following two implementations：
The first implementation, the comparison voltage acquisition module 302 includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum conduct
Optimal comparison voltage.
Preferably, above-mentioned switch module can be the diode of an one-way conduction, can also be a control circuit.Energy
Comparison voltage is compared by enough realize with reference comparison voltages, obtains wherein maximum equal as the circuit of optimal comparison voltage
Suitable for the embodiment of the present invention.
Second of implementation, the comparison voltage acquisition module 302 includes division module, constant voltage source, first unidirectional
Conducting switch and the second unidirectional conducting switch：
Division module is used to obtain the comparison voltage；
Constant voltage source is used to provide the reference comparison voltages；
When comparison voltage is more than reference comparison voltages, the first unidirectional conducting switch conducting, second unidirectional conducting switch is cut
Only, division module output comparison voltage is used as optimal comparison voltage；
When comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, first one-way conduction is opened
Cut-off is closed, constant voltage source output reference comparison voltages are used as optimal comparison voltage.
Preferably above-mentioned unidirectional conducting switch can be diode, naturally it is also possible to by logic control circuit and single knife switch
Constitute.It can be used for controlling the circuit of the division module and constant voltage source to be applied to the embodiment of the present invention, to this
Inventive embodiments are not especially limited.
Using said apparatus, the highest electricity of the signal transmitted on the cable detected by maximum level acquisition module 301
It is flat, then comparison voltage, and comparison voltage and the highest according to above-mentioned maximum level are obtained by comparison voltage acquisition module 302
The long range transfer function of the relation character zygonema cable of level, so as to ensure when long range is transmitted, the time domain of reverse control signal
Cycle is constant, it is to avoid the amplitude and edge of voltage change the influence to reverse control signal, Jin Erzeng caused by length of cable
The upper limit of length of cable is added.Above-mentioned reference comparison voltages are set greater than the multimedia data signal in the signal, it is ensured that
The multimedia data signal transmitted on cable will not be compared for reverse control signal by mistake.
The embodiment of the present invention additionally provides a kind of method for obtaining comparison voltage signal, as shown in figure 4, this method includes：
S401：Detect the maximum level of the signal transmitted on cable；
S402：Comparison voltage is obtained according to the maximum level detected；
S403：Comparison voltage is compared with reference comparison voltages, and obtains wherein maximum as most preferably more electric
The long range transfer function of the relation character zygonema cable of pressure, the comparison voltage and maximum level, the reference comparison voltages are more than described
Multimedia data signal in the signal transmitted on cable, and less than limit comparison voltage, the limit comparison voltage exists with cable
The maximum level exported during limiting length meets long range transfer function.
Using the above method, pass through the maximum level of the signal transmitted on the cable that is transmitted on the cable that detects, then root
Comparison voltage is obtained according to above-mentioned maximum level, and comparison voltage and the long range of the relation character zygonema cable of the maximum level are transmitted
Function.Ensure that the time domain cycle of reverse control signal is constant when long range is transmitted, it is to avoid voltage caused by length of cable
Amplitude and edge change the influence to reverse control signal, and then add the upper limit of length of cable.Above-mentioned reference comparison voltages
It is set greater than the multimedia data signal in the signal, it is ensured that the multimedia data signal transmitted on cable will not be missed
Compare for reverse control signal.
The embodiment of the present invention additionally provides a kind of reverse control signal extraction element, as shown in figure 5, the device includes：
Maximum level acquisition module 301, for detecting that cable uploads the maximum level of defeated signal；
Comparison voltage acquisition module 302, the maximum level for being detected according to maximum level acquisition module 301, which is obtained, to be compared
It is compared compared with voltage, and by the comparison voltage and reference comparison voltages, obtains wherein maximum as optimal comparison voltage, should
The relation character of comparison voltage and the maximum level closes the long range transfer function for stating cable, and the reference comparison voltages are more than institute
The multimedia data signal in the signal transmitted on cable is stated, and less than limit comparison voltage, the limit comparison voltage and cable
The maximum level exported in limiting length meets long range transfer function；
Voltage comparison module 501, for the signal transmitted on cable to be compared with above-mentioned optimal comparison voltage, so that
Extract the reverse control signal in the signal transmitted on cable.
The maximum level of the signal transmitted on the cable detected by maximum level acquisition module 301, then by comparing
Voltage acquisition module 302 obtains comparison voltage according to above-mentioned maximum level, will be transmitted using voltage comparison module 501 on cable
Signal is compared with optimal comparison voltage, so that the reverse control signal in the signal transmitted on cable is extracted, and it is relatively more electric
Pressure and the long range transfer function of the relation character zygonema cable of the maximum level.Utilize said apparatus, it is ensured that transmit in long range
When, the time domain cycle of reverse control signal is constant, it is to avoid the amplitude and edge of voltage change to reverse caused by length of cable
The influence of control signal, and then add the upper limit of length of cable.Above-mentioned reference comparison voltages are set greater than in the signal
Multimedia data signal, it is ensured that the multimedia data signal transmitted on cable will not be compared for reverse control signal by mistake.
Preferably, above-mentioned maximum level acquisition module 301 is peak detection module.
Preferably, above-mentioned comparison voltage acquisition module 302 can include but are not limited to following two implementations：
The first implementation, the comparison voltage acquisition module 302 includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum conduct
Optimal comparison voltage.
Second of implementation, the comparison voltage acquisition module 302 includes division module, constant voltage source, first unidirectional
Conducting switch and the second unidirectional conducting switch：
Division module is used to obtain the comparison voltage；
Constant voltage source is used to provide the reference comparison voltages；
When comparison voltage is more than reference comparison voltages, the first unidirectional conducting switch conducting, second unidirectional conducting switch is cut
Only, division module output comparison voltage is used as optimal comparison voltage；
When comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, first one-way conduction is opened
Cut-off is closed, constant voltage source output reference comparison voltages are used as optimal comparison voltage.
The embodiment of the present invention additionally provides a kind of reverse control signal extracting method, as shown in fig. 6, this method includes：
S601：Detect the maximum level of the signal transmitted on cable；
S602：Comparison voltage is obtained according to the maximum level detected；
S603：Comparison voltage is compared with reference comparison voltages, and obtains wherein maximum as most preferably more electric
Pressure, the comparison voltage and the relation character of above-mentioned maximum level close the long range transfer function for stating cable, the reference comparison voltages
More than the multimedia data signal in signal, and less than limit comparison voltage, the limit comparison voltage is with cable in limiting length
When the maximum level that exports meet long range transfer function.
S604：Above-mentioned optimal comparison voltage and the signal that is transmitted on cable are compared, transmitted so as to extract on cable
Signal in reverse control signal.
By the maximum level of the signal transmitted on the cable that detects, obtain more electric further according to above-mentioned maximum level
Pressure, the signal transmitted on cable is compared with optimal comparison voltage, so that the reverse control signal in signal is extracted, and ratio
Compared with voltage and the long range transfer function of the relation character zygonema cable of the maximum level.Utilize the above method, it is ensured that over long distances
During transmission, the time domain cycle of reverse control signal is constant, it is to avoid the amplitude of voltage and edge change pair caused by length of cable
The influence of reverse control signal, and then add the upper limit of length of cable.Above-mentioned reference comparison voltages are set greater than the letter
Multimedia data signal in number, it is ensured that the multimedia data signal transmitted on cable will not be compared by mistake to be believed for Reverse Turning Control
Number.
Below so that the long range transfer function of cable meets the charging and recharging model of electric capacity as an example, the embodiment of the present invention is made to have
Body explanation.
The charge and discharge process of electric capacity is first introduced below.
Fig. 7 show capacitor charging circuit schematic diagram, and the circuit includes resistance R, electric capacity C and constant voltage source Va, the perseverance
The constant voltage for determining voltage source offer is VC, when being charged to some time t, the voltage Vt such as formula at electric capacity C two ends（1）Institute
Show：
Vt=VC*e^（t/（R*C））（1）；
Wherein, e is a math constant.
Fig. 8 show capacitor discharging circuit schematic diagram, and the circuit includes resistance R and electric capacity C.Assuming that before discharge, electricity
The voltage for holding C two ends is VC, when discharging into some time t, the voltage Vt such as formula at electric capacity C two ends（2）It is shown：
Vt=VC*（1—e^（t/（R*C）））（2）
Wherein, e is a math constant.
Because the long range transfer function of cable meets the charging and recharging model of electric capacity, then the rising edge of signal can be modeled as
The process charged to electric capacity, the trailing edge of signal can be modeled as the process discharged electric capacity.Ensure to transmit through long-distance
The reverse control signal time domain cycle is constant afterwards, it is only necessary to ensure in same period, before and after signal attenuation, rising edge and optimal ratio
Compared with difference of the intersection point in time domain of voltage waveform, and trailing edge and optimal comparison voltage waveform difference of the intersection point in time domain
It is equal.I.e. in corresponding capacitor charge and discharge model, when the charging interval is identical with discharge time, the magnitude of voltage phase at electric capacity two ends
Together.According to the time of the discharge and recharge of above-mentioned introduction and the relation formula of electric capacity both end voltage（1）And formula（2）, it is ensured that charging
When time is identical with discharge time, the magnitude of voltage at electric capacity two ends is identical, then need to only ensure the voltage Vt=VC/2 at electric capacity two ends.Then
Optimal comparison voltage is 1/2nd of reverse control signal maximum level.
The device of extraction reverse control signal in the embodiment of the present invention is included：Maximum level acquisition module 301, comparison are electric
Press acquisition module 302 and voltage comparison module 501.Below by taking circuit theory diagrams as an example, the embodiment of the present invention is illustrated, but
It is not limited in circuit described below, each functional module can use the functional module met in the embodiment of the present invention, or
Person's hardware programmable device etc..Such as maximum level acquisition module 301 is peak detection module, and the peak detection module
This can be completed using peak detection chip and realize function.
As shown in Figure 9, it is assumed that maximum level acquisition module 301 includes diode D1（When the forward voltage drop of diode is more than
During certain value, it is turned on, and otherwise it is in off state）, electric capacity C1（Electric capacity is used for energy storage）；Comparison voltage acquisition module 302
Including diode D2 and D3, resistance R1 and resistance R2, a constant voltage source Vr（For providing a constant voltage Vref）, voltage
Comparison module 501 is realized by voltage comparator F.
For in whole Multimedia Transmission System, in addition to back-end processing and analogue camera and cable, it is above-mentioned
The device for extracting reverse control signal is arranged at analogue camera.
It is specifically described below according to how the circuit of above-mentioned offer obtains optimal comparison voltage.
Before reverse control signal appearance, the signal transmitted on cable is multimedia data signal, in Reverse Turning Control letter
When number occurring, the signal transmitted on cable is mixed signal.Mixed signal includes multimedia data signal and Reverse Turning Control letter
Number.As shown in Figure 10, wherein VCC represents the maximum level of multimedia data signal to the waveform of a points shown in Fig. 9, and VDD represents anti-
To the maximum level of control signal；When after peak detection module, signal will be maintained in the voltage of the b points shown in Fig. 9
The middle maximum level occurred, as shown in Figure 10, before reverse control signal appearance, b points are maintained at multimedia number to b points waveform
It is believed that number maximum level VCC；When reverse control signal one occurs, b points remain the maximum level VDD of reverse control signal；
Next, when when the magnitude of voltage of b points is VCC, diode D2 cut-offs, diode D3 is turned on, then the d shown in Fig. 9
The voltage of point is Vref, when the magnitude of voltage of b points is VDD, diode D2 conductings, and diode D3 cut-offs are electricity in the voltage of d points
The voltage at R2 two ends is hindered, i.e., with it, using the principle of diode, by optimal comparison voltage and reference comparison voltages Vref
It is compared, which voltage is high, which voltage the output of d points is.Ensure when reverse control signal occurs, the output of d points
Optimal comparison voltage is equal to the half of reverse control signal maximum level, only need to ensure R1=R2.As shown in Figure 10, anti-
Before occurring to control signal, the voltage of d points is reference comparison voltages Vr.After reverse control signal occurs, the voltage of d points is
VDD/2。
And Vr setting here, it is ensured that the constant voltage Vref that Vr is provided is more than multimedia data signal maximum level
VCC.The purpose so set is avoided before reverse control signal occurs, and multimedia data signal is compared into reverse control by mistake
Signal processed, because if Vref is higher than the level of multimedia data signal, then the signal on cable will not be by voltage comparison module
501 compare for high level, the output low level of voltage comparison module 501, when only occurring the reverse control signal higher than Vref,
Can the output high level of trigger voltage comparison module 501.
Handled by the method described in the embodiment of the present invention or device, the reverse control signal time domain after transmitting over long distances
It is cycle, equal with the time domain cycle of original reverse control signal.Handled using method or apparatus provided in an embodiment of the present invention
Reverse control signal afterwards so that the decay at signal amplitude or edge will not produce influence to the time domain cycle, and then increase
The transmission range of reverse control signal；And in implementation process, influence will not be produced on multimedia data signal, circuit
Design is simple, strong adaptability, portable high.
It should be understood by those skilled in the art that, embodiments of the invention can be provided as method, system or computer program
Product.Therefore, the present invention can be using the reality in terms of complete hardware embodiment, complete software embodiment or combination software and hardware
Apply the form of example.Moreover, the present invention can be used in one or more computers for wherein including computer usable program code
Usable storage medium（Including but not limited to magnetic disk storage, CD-ROM, optical memory etc.）The computer program production of upper implementation
The form of product.
The present invention is with reference to method according to embodiments of the present invention, equipment（System）And the flow of computer program product
Figure and/or block diagram are described.It should be understood that can be by every first-class in computer program instructions implementation process figure and/or block diagram
Journey and/or the flow in square frame and flow chart and/or block diagram and/or the combination of square frame.These computer programs can be provided
The processor of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing devices is instructed to produce
A raw machine so that produced by the instruction of computer or the computing device of other programmable data processing devices for real
The device for the function of being specified in present one flow of flow chart or one square frame of multiple flows and/or block diagram or multiple square frames.
These computer program instructions, which may be alternatively stored in, can guide computer or other programmable data processing devices with spy
Determine in the computer-readable memory that mode works so that the instruction being stored in the computer-readable memory, which is produced, to be included referring to
Make the manufacture of device, the command device realize in one flow of flow chart or multiple flows and/or one square frame of block diagram or
The function of being specified in multiple square frames.
These computer program instructions can be also loaded into computer or other programmable data processing devices so that in meter
Series of operation steps is performed on calculation machine or other programmable devices to produce computer implemented processing, thus in computer or
The instruction performed on other programmable devices is provided for realizing in one flow of flow chart or multiple flows and/or block diagram one
The step of function of being specified in individual square frame or multiple square frames.
, but those skilled in the art once know basic creation although preferred embodiments of the present invention have been described
Property concept, then can make other change and modification to these embodiments.So, appended claims are intended to be construed to include excellent
Select embodiment and fall into having altered and changing for the scope of the invention.
Obviously, those skilled in the art can carry out the essence of various changes and modification without departing from the present invention to the present invention
God and scope.So, if these modifications and variations of the present invention belong to the scope of the claims in the present invention and its equivalent technologies
Within, then the present invention is also intended to comprising including these changes and modification.
Claims (10)
1. a kind of device for obtaining comparison voltage signal, it is characterised in that including：
Maximum level acquisition module, for detecting that cable uploads the maximum level of defeated signal；
Comparison voltage acquisition module, the maximum level for being detected according to the maximum level acquisition module obtains more electric
Pressure, and the comparison voltage and reference comparison voltages are compared, obtain wherein maximum described as optimal comparison voltage
Optimal comparison voltage is used to extracting the reverse control signal in the signal transmitted on the cable, the comparison voltage with it is described most
The relation of high level meets the long range transfer function of the cable, and the reference comparison voltages are more than what is transmitted on the cable
Multimedia data signal in signal, and less than limit comparison voltage, the limit comparison voltage and the cable are long in the limit
The maximum level exported when spending meets long range transfer function, wherein optimal comparison voltage is reverse control signal maximum level
1/2nd.
2. device as claimed in claim 1, it is characterised in that the maximum level acquisition module is peak detection module.
3. device as claimed in claim 1, it is characterised in that the comparison voltage acquisition module includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum as optimal
Comparison voltage.
4. device as claimed in claim 1, it is characterised in that the comparison voltage acquisition module includes division module, constant
Voltage source, the first unidirectional conducting switch and the second unidirectional conducting switch：
The division module is used to obtain the comparison voltage；
The constant voltage source is used to provide the reference comparison voltages；
When the comparison voltage is more than the reference comparison voltages, the conducting of the first unidirectional conducting switch, second one-way conduction
Switch cut-off, the division module exports the comparison voltage and is used as the optimal comparison voltage；
When the comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, described first is unidirectional
Conducting switch cut-off, the constant voltage source exports the reference comparison voltages and is used as the optimal comparison voltage.
5. a kind of method for obtaining comparison voltage signal, it is characterised in that including：
Detect the maximum level of the signal transmitted on cable；
Comparison voltage is obtained according to the maximum level detected；
The comparison voltage and reference comparison voltages are compared, and obtain wherein maximum and are used as optimal comparison voltage, institute
The relation for stating comparison voltage and the maximum level meets the long range transfer function of the cable, and the reference comparison voltages are big
Multimedia data signal in the signal transmitted on the cable, and less than limit comparison voltage, the limit comparison voltage
The maximum level exported with the cable in limiting length meets long range transfer function, wherein optimal comparison voltage is reverse
/ 2nd of control signal maximum level.
6. a kind of device for extracting reverse control signal, it is characterised in that including：
Maximum level acquisition module, for detecting that cable uploads the maximum level of defeated signal；
Comparison voltage acquisition module, the maximum level for being detected according to the maximum level acquisition module obtains more electric
Pressure, and the comparison voltage and reference comparison voltages are compared, obtain wherein maximum described as optimal comparison voltage
Comparison voltage and the relation of the maximum level meet the long range transfer function of the cable, and the reference comparison voltages are more than
Multimedia data signal in the signal transmitted on the cable, and less than limit comparison voltage, the limit comparison voltage with
The maximum level that the cable is exported in limiting length meets long range transfer function, wherein optimal comparison voltage is reverse control
/ 2nd of signal maximum level processed；
Voltage comparison module, for the signal transmitted on the cable to be compared with the optimal comparison voltage, so as to carry
Take the reverse control signal in the signal transmitted on the cable.
7. device as claimed in claim 6, it is characterised in that the maximum level acquisition module is peak detection module.
8. device as claimed in claim 6, it is characterised in that the comparison voltage acquisition module includes：
Division module, for obtaining the comparison voltage；
Constant voltage source, for providing the reference comparison voltages；
Switch module, for the comparison voltage and reference comparison voltages to be compared, obtains wherein maximum as optimal
Comparison voltage.
9. device as claimed in claim 6, it is characterised in that the comparison voltage acquisition module includes division module, constant
Voltage source, the first unidirectional conducting switch and the second unidirectional conducting switch：
The division module is used to obtain the comparison voltage；
The constant voltage source is used to provide the reference comparison voltages；
When the comparison voltage is more than the reference comparison voltages, the conducting of the first unidirectional conducting switch, second one-way conduction
Switch cut-off, the division module exports the comparison voltage and is used as the optimal comparison voltage；
When the comparison voltage is less than the reference comparison voltages, the second unidirectional conducting switch conducting, described first is unidirectional
Conducting switch cut-off, the constant voltage source exports the reference comparison voltages and is used as the optimal comparison voltage.
10. a kind of method for extracting reverse control signal, it is characterised in that including：
Detect the maximum level of the signal transmitted on cable；
Comparison voltage is obtained according to the maximum level detected；
The comparison voltage and reference comparison voltages are compared, and obtain wherein maximum and are used as optimal comparison voltage, institute
The relation for stating comparison voltage and the maximum level meets the long range transfer function of the cable, and the reference comparison voltages are big
Multimedia data signal in the signal transmitted on the cable, and less than limit comparison voltage, the limit comparison voltage
The maximum level exported with the cable in limiting length meets long range transfer function, wherein optimal comparison voltage is reverse
/ 2nd of control signal maximum level；
The optimal comparison voltage and the signal that is transmitted on the cable are compared, so as to extract what is transmitted on the cable
Reverse control signal in signal.
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| CN1160970A (en) * | 1996-03-29 | 1997-10-01 | 西安电子科技大学 | Industrial TV transmission system |
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| CN1564591A (en) * | 2004-04-09 | 2005-01-12 | 南京大学 | Method and appts. for duplex transmitting video signal and controlling data |
| JP4141757B2 (en) * | 2002-07-24 | 2008-08-27 | フジノン株式会社 | Electronic endoscope device |
| CN101304477A (en) * | 2007-05-09 | 2008-11-12 | 奇景光电股份有限公司 | Apparatus and method for separating synchronizing signal in video signal |
| CN201937769U (en) * | 2011-03-14 | 2011-08-17 | 江苏技术师范学院 | Video monitoring system for single-cable comprehensive data service transmission |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1219400C (en) * | 2001-06-25 | 2005-09-14 | 松下电器产业株式会社 | Baseband video transmission system |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1160970A (en) * | 1996-03-29 | 1997-10-01 | 西安电子科技大学 | Industrial TV transmission system |
| CN1257272A (en) * | 1998-11-12 | 2000-06-21 | 索尼公司 | Video frequency processor |
| JP4141757B2 (en) * | 2002-07-24 | 2008-08-27 | フジノン株式会社 | Electronic endoscope device |
| CN1564591A (en) * | 2004-04-09 | 2005-01-12 | 南京大学 | Method and appts. for duplex transmitting video signal and controlling data |
| CN101304477A (en) * | 2007-05-09 | 2008-11-12 | 奇景光电股份有限公司 | Apparatus and method for separating synchronizing signal in video signal |
| CN201937769U (en) * | 2011-03-14 | 2011-08-17 | 江苏技术师范学院 | Video monitoring system for single-cable comprehensive data service transmission |
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| CN104749974A (en) | 2015-07-01 |
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