CN1049260A - Closed-circuit television system with couple of conductor control - Google Patents
Closed-circuit television system with couple of conductor control Download PDFInfo
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- CN1049260A CN1049260A CN 90106845 CN90106845A CN1049260A CN 1049260 A CN1049260 A CN 1049260A CN 90106845 CN90106845 CN 90106845 CN 90106845 A CN90106845 A CN 90106845A CN 1049260 A CN1049260 A CN 1049260A
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Abstract
The present invention relates to closed-circuit TV control system switching control method and device, be used for showing and magnetic recording, belong to closed-circuit television control.It is made up of video camera, camera control unit, camera switcher, user's switch, operation keyboard and cable, it is indicated distinct device, is finished the instruction code that the different operating content becomes 8 bit binary data by the keyboard matrix handle, go to control the output of 8 audio frequency pure oscillation signals, become composite signal through mixer amplifier, pass to the receiving terminal of equipment with couple of conductor, frequency-selecting filter and auxiliary circuit with 8 parallel connections, recover 8 parallel-by-bit numbers, realized using couple of conductor to replace the function of many control lines.
Description
The present invention relates to control method and device to various closed circuit television equipments, comprise video camera is carried out attitude control, to the remote control as illumination and alert device of various signal switching apparatus and attached field apparatus, the operation that also can be used for other image processing and switching system and magnetic recording system is controlled.Belong to the application television technical field.
At present, closed circuit television equipment is carried out remote control and uses three class ways substantially:
1. directly control: the many buttons on the operating desk all connect with different controlled devices respectively with individual conductor with switch, directly or by relay handle controlled device by switch, lead is many, installation and maintenance are all inconvenient, increasing along with distance, the lead loss makes and drives the efficient reduction, energy resource consumption increases, and reliability is low, the cost height.
2. digital control: transmit the serial digital instruction with couple of conductor, the circuit more complicated, serial digital signal is subjected to impulse disturbances to cause the misoperation of controlled device easily.
3. two-tone signal control: number of instructions is few, and function is few.
Purpose of the present invention is exactly in order to overcome above-mentioned way deficiency technically, provide a kind of with the method for couple of conductor parallel convey 8 bit word instructions and the practical closed-circuit television system of utilizing this method to realize, this system possesses numerically controlled whole advantage, but it is lower than serial transfer digital command cost, strong anti-interference performance resembles simultaneously the two-tone signal control simple again.
Simple principle of the present invention is as follows:
Under normal conditions, couple of conductor can only transmit 1 bit binary number signal, is " 1 " or " 0 " with high or low level meter registration word promptly, and 8 bit digital just need (simultaneously) transmission that could walk abreast of at least 9 leads.
Yet, couple of conductor can transmit the voice frequency tone signal of several different frequencies without interfering with each other simultaneously, with 8 audio frequency oscillators that frequency is different, produce simultaneously frequency be respectively F0, F1, F2 ..., F7 sinusoidal signal, through 8 be subjected to respectively 8 bit binary data D0, D1, D2 ..., D7 control audio switch, allow the data be that 1 o'clock respective oscillator has signal output, data are 0 o'clock respective oscillator no-output, these 8 controlled output signals are given mixer amplifier simultaneously, and mixed composite signal is exported through emitter follower.Certain frequency has or not that just to represent certain bit digital be 1 or 0 in the output signal, as: it is that the signal indication D0 of F0 is for " 1 " that frequency is arranged, do not have frequency be the signal indication D0 of F0 for " 0 ", be that the signal of F1-F7 all is that signal indication " 1 " is arranged to frequency, no signal is represented " 0 ".
This composite audio signal only needs an audio frequency amplifier to amplify as long as couple of conductor just can transmit, and an audio switch switches.
At receiving terminal, with 8 frequency-selecting filters that centre frequency is corresponding with frequency of oscillation, their input parallel connection, make them receive composite audio signal simultaneously, certain frequency is arranged in the composite signal, respective filter just has output, the output of 8 filters just recovered again 8 parallel-by-bit binary numeral D0, D1, D2 ..., D7.
Above-mentioned basic principle is implemented by following way in the present invention: this closed-circuit television system is by video camera and auxiliary equipment (comprising The Cloud Terrace and camera lens) A, camera control unit B, camera switcher C, user's switch D, monitor E(or magnetic recording equipment), connect between operation keyboard G and the equipment usefulness by a coaxial line and two cables that audio wire is formed.
By special single cable connection, comprise high frequency coaxial line and two audio wires in the cable between the equipment.The coaxial line of picture signal in cable of video camera output passes to camera switcher, passes to user's switch through coaxial line again after selecting to switch, and finally passes to the monitor of monitoring terminal.The audio wire of the control signal that the operation keyboard of monitoring terminal sends in cable passes to user's switch, user's switch is connected picture signal and this user's monitor according to the indication of control signal, and this user's control signal and camera switcher and camera control unit connection, the audio wire of all control signals in cable is by monitoring that end passes to controlled device.The all devices of native system except that operation keyboard all do not have any manual operation key button, all moves according to the instruction of control signal.Camera control unit drives the The Cloud Terrace left rotation and right rotation, changes the video camera luffing angle, regulates focusing, changes lens focus, switch camera masking and camera power supply according to instruction; User's switch turns on and off the picture signal of leading to different user according to instruction, and user's control signal and miscellaneous equipment are connected; Camera switcher is issued the user to the picture signal of appointment video camera according to instruction, also control signal is issued the appointment camera control unit simultaneously.The native system all devices all is digital control, and all instructions are binary digital code, comprises the EIC equipment identification code of indication distinct device action and the numeric data code of the different movement contents of explanation in the instruction code.Represent that the control signal of different binary digital codes instruction only uses a pair of audio wire parallel transmission.In native system, express the instruction that all closed circuit television equipments are controlled with 7 bit binary number codes.And all controlled equipment all only need be deciphered number relevant with it in the instruction code, needn't decipher whole 7 figure place sign indicating numbers.As long as user's switch is deciphered 2 in 7, as long as camera switcher is deciphered 4, as long as camera control unit is deciphered 5 figure place sign indicating numbers.
The control method of native system is to produce and represent the method for 8 binary code command signals and to the method for deciphering of sort signal with the couple of conductor parallel convey with a kind of.Instruction signal generator in its operation keyboard comprises the audio frequency sinusoidal oscillator of 8 different frequencies, and 8 frequencies that they produce are represented 8 bit sign indicating numbers respectively.The matrix circuit that keyboard is made up of diode network is when the different operating button is connected and line output 8 bit sign indicating number D0-D7.This number is delivered to instruction signal generator, controls the output of 8 audio frequency oscillators respectively, and these 8 controlled output signals are given mixer amplifier simultaneously, and mixed composite signal is exported through emitter follower.Having or not of certain frequency represents that promptly certain figure place sign indicating number is 1 or is 0 in the output signal.
Deciphering with 8 centre frequency frequency-selecting filters corresponding with frequency of oscillation of composite audio signal finished, in parallel the filter input, make them receive composite audio signal simultaneously, corresponding filter just has output when having a certain frequency in the input signal, and 8 filters outputs have just recovered 8 parallel-by-bit binary numerals.
The coaxial line of picture signal in cable of video camera output delivered to the image input socket of camera switcher, and camera switcher can be selected to switch to 8 video cameras.8 image input sockets are arranged, and two image output sockets are by the same picture signal of instruction output.8 instruction output sockets are given the camera control unit of appointment command signal respectively by instruction.The picture signal of camera switcher output is given the image input of user's switch, and the instruction input of camera switcher is exported the signal that gets instruction from the instruction of user's switch.4 images output of user's switch is given 4 users' monitor picture signal respectively by instruction, and 4 instruction inputs are respectively from 4 users' the operation keyboard signal that gets instruction.
Operation keyboard is made up of keyboard matrix and instruction signal generator two large divisions.Keyboard matrix comprises single-pole single-throw(SPST push-button switch and diode matrix network, and under the situation of not pressing any button, all numbers of keyboard matrix and line output are " 0 " entirely, when a certain button is pressed, promptly exports corresponding parallel binary instruction code.Instruction signal generator comprises 8 audio frequency sinusoidal oscillators, the output of each oscillator all has a triode short switch, they are controlled by the digital signal of keyboard matrix output respectively, when keyboard matrix output is " 0 " entirely, all switch triodes are all saturated, and all audio frequency oscillator outputs are all by short circuit; When who was " 1 " in pressing a certain key switch, instruction code, corresponding switch triode just ended, and the sinusoidal signal of respective oscillator output just is sent to mixer amplifier; When instruction code was " 1 " entirely, all switch triode all ended, and the audio frequency sinusoidal signal of all oscillator outputs is just all delivered to mixer amplifier simultaneously, and the composite audio signal that mixes after amplifying is exported through emitter follower.8 kinds of different frequencies of 8 audio frequency oscillator generations (F0, F1, F2 ... F7) audio frequency sinusoidal signal, respectively corresponding (D0, D1, D2,, which kind of frequency D7) 8 bit sign indicating numbers have just represent that who number is 1 in the composite audio signal, do not have which kind of frequency just to represent that who number is 0.In fact, both having made is the hugest closed-circuit television system of scale, even consider the needs that may increase in the future, the needed instruction type of control all devices also can not surpass 128 kinds, so just enough with 7 figure place sign indicating numbers.Operation keyboard only needs 7 audio frequency oscillators, the sinusoidal signal of 7 kinds of frequencies of output, and the 8th gives over to standby or does not simply adorn.
Command system provided by the present invention is arranged in the following manner: 7 figure place sign indicating number D0, and D1, D2 ..., D6 high 4 (be D6, D5, D4, D3) as EIC equipment identification code, whether their indication distinct device work; Low 3 (be D2, D1, D0) description operation content.High 4 is 1000 o'clock, and indication user switch turns on and off the command signal that the picture signal that is sent to the operation user and this user send; Low 3 is 001 connection, and low 3 is 000 judgement; High 4 is 0100 o'clock, and the indication camera switcher is connected the picture signal of corresponding video camera and corresponding camera control unit is mail in instruction by low 3 bit data, is No. 1 video camera of 001 connection and camera control unit as low 3,010-2 number, 011-3 number ... 111-7 number, 000-8 number; High 4 is 0001 o'clock, and the indication camera control unit is finished positive operation by low 3 bit data, that is: the 001-video camera is to right rotation, and 010-raises camera lens, the focusing of 011-forward, and 100-transfers big focal length ..., 111-opens aperture, and 000-connects camera power supply; High 4 is 0010 o'clock, and the indication camera control unit is finished reverse operating by low 3 bit data, that is: the 001-video camera is to anticlockwise, and 010-forces down camera lens, and 011-oppositely focuses, and 100-shortens focal length ..., 111-closes aperture, and 000-turn-offs camera power supply.
As previously mentioned: 8 bit code instruction D0, D1, D2 ..., D7 is with 8 kinds of different frequency (F0, F1, F2 ..., audio frequency sinusoidal signal F7) is represented, concrete numerical value to these 8 kinds of audio frequencies does not have absolute limitations in theory, mainly be to consider from the engineering angle, make system more economical, work more reliable, between the frequency enough big interval to be arranged, to satisfy the requirement of frequency-selecting filter selectivity, avoid causing error code; Middle part, the frequency interval that 8 audio frequencies concentrate on standard speech channel bandwidth as far as possible do not want excessive with reduce because of the inhomogeneous signal amplitude that causes of transmission channel frequency characteristic inconsistent; The numerical value of 8 audio frequencies should satisfy certain mutual mathematical relationship, can not cause interference to 8 useful frequencies to guarantee harmonic wave and combination frequency that transmission distortion causes; Need make also when selecting frequency that Resistor-Capacitor Unit numerical value and element standard ordered series of numbers meet in the oscillator.The frequency F0 of corresponding digital D0 is 1881Hz in system provided by the present invention, the F1 of corresponding D1 is 1539Hz, the F2 of corresponding D2 is 1254Hz, the F3 of corresponding D3 is 1078Hz, the F4 of corresponding D4 is 882Hz, the F5 of corresponding D5 is 719Hz, and the F6 of corresponding D6 is 588Hz, and 2148Hz is standby for the another one frequency.
Command decoder in the controlled device adopts 8 frequency-selecting filters that input is in parallel, and their centre frequency is consistent with the frequency of representing 8 figure place sign indicating numbers respectively, and their 8 outputs have just recovered 8 parallel-by-bit binary instruction codes.What the present invention specifically adopted is the phase-locked loop circuit that LM567 forms, it is characterized in that it has one to be the response band at center with f0, when a signal appears in input, its frequency within the response band scope time output current drive load resistance, make output voltage near 0, otherwise output current is 0, and output voltage is near supply voltage.
According to the above-mentioned arrangement that command system is done, different controlled devices are according to the indication action of high 4 figure place sign indicating numbers or ignore, so every kind of device just is deciphered the number relevant with it, needn't decipher whole 7 bit instruction sign indicating numbers, as: the command decoder of user's switch only need be deciphered D0 and D6, and that is to say only needs the audio signal of 1881Hz and 588Hz is responded; Camera switcher only need be deciphered D0, D1, and D2 and D5, to 1881Hz, 1539Hz, 1254Hz and 719Hz respond; Camera control unit only need be deciphered D0, D1, and D2, D3 and D4, to 1881Hz, 1539Hz, 1254Hz, 1078Hz and 882Hz respond.So user's switch only needs two kinds of frequency-selecting filters, camera switcher needs only 4 kinds of frequency-selecting filters, and as long as camera control unit is 5 kinds of frequency-selecting filters.
The explicitly parallel instruction code of the command decoder M output in user's switch drives switch N, the control signal of switch controller N output is controlled cut bank X and instruction switch Y respectively, picture signal is selectively passed to relevant User Monitor by switch X, and the command signal that the user sends by operation keyboard is sent to the camera control unit of camera switcher and appointment by switch Y.The circuit core of switch controller N is data latches 74LS75, and the D6 that exports with command decoder M does to guarantee that signal, D0 as data, export as switching controls with Q.
The explicitly parallel instruction code signal of the command decoder M output in the camera switcher drives switch controller N, the control signal of switch controller N output is controlled cut bank X and instruction switch Y respectively, specify the picture signal of video camera output to pass to user's switch by switch X, command signal is given the camera control unit of appointment by switch Y.The circuit core of switch controller N is the 3-8 decoder 74LS137 that deposits with lock, with the D5 do assurance signal of command decoder M output, and D0, D1 and D2 are as address date.
The explicitly parallel instruction code signal control drive circuit Q of the command decoder M output in the camera control unit, drive circuit has two integrated circuit 74LS138, and D3 and the D4 with command decoder M output makes to guarantee signal, D0 respectively, D1, D2 give two 74LS138 simultaneously as data.
Description of drawings:
Fig. 1: system block diagram
A: video camera (comprising The Cloud Terrace and camera lens)
B: camera control unit
C: camera switcher
D: user's switch
E: monitor
G: operation keyboard
Fig. 2: operation keyboard block diagram
H: keyboard matrix
K: instruction signal generator
Fig. 3: user's switch block diagram
M: command decoder
N: switch controller
X: cut bank
Y: instruction switch
1,2,3,4, connect 4 users' monitor respectively
1 ', 2 ', 3 ', 4 ', connect 4 users' operation keyboard respectively
Fig. 4: camera switcher block diagram
M: command decoder
N: switch controller
X: cut bank
Y: instruction switch
1-8 connects 8 camera control units respectively
1 '-8 ' respectively connects the picture signal output of 8 video cameras
Fig. 5: camera control unit block diagram
M: command decoder
Q: controlled device drive circuit
Fig. 6: keyboard matrix circuit figure
Fig. 7: instruction signal generator circuit diagram
Fig. 8: pierce circuit figure
Fig. 9: frequency-selecting filter circuit diagram
Figure 10: instruction switch circuit figure
Figure 11: User Recognition and control switching circuit figure
Figure 12: instruction decoding and control switching circuit figure
Figure 13: switching controls oscillogram
Figure 14: instruction switch circuit figure
Figure 15: camera control unit circuit diagram
Figure 16: camera control unit drive circuit figure
Embodiment:
Fig. 1 is the block diagram of native system.The present invention is by video camera and auxiliary equipment (The Cloud Terrace and camera lens) A, camera control unit B, and camera switcher C, user's switch D, monitor (or magnetic recording equipment) E, operation keyboard G forms with the coaxial cable that has two leads.
Fig. 2 is the operation keyboard block diagram.Operation keyboard comprises keyboard matrix H and instruction signal generator K two major parts.Fig. 6 is keyboard matrix circuit figure, and key switch is often to drive single-pole single-throw switch (SPST) entirely, and switching diode is with IN4148 or similar model, all switch 1-8,1 '-8 ', 11-18,9,10 end ground connection all, output lead D0-D6 connects+the 10V power supply by 7 resistance R a respectively, and the diode matrix network between key switch and the output line is arranged in the following manner, that is: switch 1,3,5,7,9,11,13,15,17,1 ', 3 ', 5 ', 7 ' and D0 between, switch 2,3,6,7,12,13,16,17,2 ', 3 ', 6 ', 7 ' and D1 between, switch 4,5,6,7,14,15,16,17,4 ', 5 ', 6 ', 7 ' and D2 between, switch 1,2,3,4,5,6,7,8 and D3 between, switch 1 ', 2 ', 3 ', 4 ', 5 ', 6 ', 7 ', 8 ' and D4 between, switch 11,12,13,14,15,16,17,18 and D5 between and connect with switching diode respectively between switch 9,10 and the D6, diode cathode connects the DOL Data Output Line negative switch, under the situation of not pressing any key switch, all not conductings of diode, all data wires are supply voltage+10V, represent number 0000000, (the output positive voltage represents that data are " 0 ", and 0 voltage is represented " 1 ").The diode that negative pole and this switch link when a certain key switch is pressed is with regard to conducting, so the data wire that links with these diode cathodes just is clamped to 0 by diode ground connection, voltage, dateout " 1 ".
The rest may be inferred.
Press key 1 ', D0 and D4 voltage are 0, output digital 0010001;
Press key 2 ', D1 and D4 voltage are 0, output digital 0010010;
Press key 3 ', D0, D1 and D4 voltage are 0, output digital 0010011;
The rest may be inferred.
Press key 11, D0 and D5 voltage are 0, output digital 0100001;
Press key 12, D1 and D5 voltage are 0, output digital 0100010;
Press key 13, D0, D1 and D5 voltage are 0, output digital 0100011;
The rest may be inferred.
Press key 9, D0 and D6 voltage are 0, output digital 1000001.
Press key 10, D6 voltage is 0, output digital 1000000.
High 4 indication distinct devices of 7 bit instruction codes are finished different operating, low 3 description operation contents.
High 4 is 1000 o'clock, and indication user switch turns on and off picture signal that is sent to the user and the command signal that this user sends, and hanging down 3 is that 001 expression is connected, 000 expression cut-out.
High 4 is 0100 o'clock, the indication camera switcher is connected the picture signal of corresponding video camera by low 3 bit data and simultaneously command signal and corresponding camera control unit is connected, as low 3 is No. 1 video camera of 001 connection and camera control unit, 010 connects No. 2,011 connects No. 3,, 111 connect No. 7, and 000 connects No. 8.
High 4 is that 0001 o'clock indication camera control unit is finished positive operation by low 3 figure place sign indicating numbers, that is: 001-command signal in the duration actuated camera to right rotation, command signal finishes promptly to stop the rotation, 010-command signal in the duration actuated camera raise camera lens, command signal finishes just to stop, 011-is the forward focusing in the instruction duration, 100-extends focal length in the instruction duration, 111-opens aperture and is held open after command signal finishes, 000-connects camera power supply, and finishes the back maintenance in command signal and connect.
High 4 is 0010 o'clock, and the indication camera control unit is finished reverse operating by low 3 figure place sign indicating numbers.That is: 001-command signal in the duration actuated camera to anticlockwise, 010-command signal in the duration actuated camera force down camera lens, 011-is in command signal oppositely focusing in the duration, 100-shortens focal length in command signal in the duration, 111-closes aperture and finishes the back in command signal and keeps closing, and 000-turn-offs camera power supply and finishes the back in command signal and keeps turn-offing.
As mentioned above, when not pressing any button, 7 bit sign indicating numbers of keyboard matrix and line output are 0 entirely, when a certain button is pressed, keyboard matrix is just exported 7 bit instruction codes with specific connotation, and different key buttons send different codes, handles distinct device and finishes different operating.
Fig. 7 is the electrical schematic diagram of instruction signal generator, and it comprises 7 wien-bridge oscillators, 7 triode switches, and mixer amplifier and emitter follower, 7 shared 2 integrated circuit LM324 of audio frequency oscillator, every comprises 4 low consumed power operational amplifiers.
Each oscillator only need be with an operational amplifier, the oscillator basic circuit is shown in Fig. 8, operational amplifier is by+10V and ground power supply, the suitable power supply mid point of+5V, meet 33K negative feedback resistor and two limiter diode D1 between operational amplifier reverse input end and the output, D2, diode can be with IN4148 or similar model, connect 4.7K half adjustable potentiometer between reverse input end and the power supply mid point so that adjust oscillation amplitude, meet R0 between in-phase input end and the output, the series circuit that C0 forms, meet R0 between in-phase input end and the power supply mid point, the parallel circuits that C0 forms, this is the typical connection of Wen's bridge, there is not special character, frequency of oscillation depends on C0, R0,8 oscillators produce the audio oscillation of 8 kinds of different frequencies, their C0, R0 numerical value is also just different certainly, and the concrete numerical value of 8 audio frequencies and corresponding resistance capacitance numerical value are shown in table 1:
Frequency 2418Hz can not adorn as standby.Highest frequency 1881Hz represents lowest order D0, and low-limit frequency 588Hz represents highest order D6, and 1539Hz represents D1, and 1254Hz represents D2, and 1078Hz represents D3, and 882Hz represents D4, and 719Hz represents D5.
Table 1
As shown in Figure 7; 7 oscillator outputs are received 8 collector electrodes as the triode of short switch through R1 respectively; transistor base links through diode D and corresponding Data In-Line D0-D7; D can be with IN4148 or similar model; (digital is " 1 ") just ends with the triode that it joins when a certain data line voltage of keyboard matrix is 0; being equivalent to short switch opens; the sinusoidal signal of oscillator output is just delivered to the reverse input end of integrated circuit LM741 by C1 and R2; operational amplifier LM741 also is by+10V and ground power supply; + 5V is the power supply mid point; the output signal of 7 oscillators is through C1; be added to reverse input end behind the R2 together; meet negative feedback resistor R3 between reverse input end and the output; the composite signal of LM741 output is delivered to the emitter follower base stage through partiting dc capacitor C2; the emitter follower base stage is linked by R4 and power supply mid point, and R5 is the emitter resistance of emitter follower, and signal is finally exported by the P point; R6 is a protective resistance, under the situation of output short-circuit emitter follower is shielded.
What operation keyboard was exported is a composite signal that comprises the sinusoidal signal that may reach 7 different frequencies, controlled device is received after this signal, with corresponding with the signal frequency respectively frequency-selecting filter of 7 centre frequencies, their input parallel connection, make them receive composite audio signal simultaneously, when certain frequency was arranged in the composite signal, respective filter just had output, and 7 filter outputs have just recovered 7 parallel-by-bit binary instruction codes.
In system provided by the present invention, all controlled devices are deciphered instruction all same frequency-selecting filter, be different occasion filter center frequency differences, Fig. 9 is the filter circuit figure that forms with integrated circuit LM567 and peripheral circuit, this is the phase-locked loop circuit of the extensive use of LM567, + 5V power supply is powered to it by 4 pin and 7 pin, signal is gone into by 3 footnotes, 8 pin are output, output and+meet load resistance RL between the 5V, meet capacitor C i between 2 pin and the ground, the response speed of its decision phase-locked loop is as frequency-selecting filter, it determines filtering bandwidth, connect capacitor C 0 between 1 pin and the ground, it determines output delay time, when requiring filter that different output delay is arranged, will be with the C0 of different numerical value, capacitor C p between 6 pin and the ground and 5, all-in resistance Rp between 6 pin is the key element of decision filter center frequency, and corresponding to different frequency, their numerical value is listed in table 2.
Since the filter center frequency must with represent the number the signal frequency strict conformance, the electronic component parameter of any reality all has error, so Rp adopts a fixed resistance and an adjustable resistance series connection in Fig. 9, centre frequency depends on the product of Cp, Rp, so be that the resistance or the error of electric capacity all can remedy by the adjustment to adjustable resistance, in system provided by the present invention, adjustable resistance is 4.7K, the resistance correspondence frequency from low to high of fixed resistance Rp ' is respectively 16K, 13K, 10K, 8.2K, 13K, 10K, 8.2K and 5.6K.
All are accepted the controlled device of instruction and all decipher out the command code that needs separately with same manner, high 4 of instruction code is the identification code of controlled device, user's switch is started by D6, D5 starts camera switcher, D3 and D4 start the forward and the reverse operating logic of camera control unit, any equipment all only need be deciphered part relevant with it in the instruction code, needn't decipher whole 7 figure place sign indicating numbers.
Fig. 3 is the block diagram of user's switch, 1 ', 2 ', 3 ', 4 ' respectively connect four users' monitor, 1,2,3,4 obtain command signal from four users' operation keyboard respectively, and input instruction signal is deciphered rear feed by command decoder M and given switch N, remove to control cut bank X and instruction switch Y by the control signal of switch controller N output, picture signal is given the user selectively by switch X, and with past camera switcher, concrete electrical schematic diagram is seen Figure 10 and Figure 11 to the command signal that relevant user sends by switch Y.
Figure 11 is User Recognition and the switch control portion parallel circuit in user's switch.Because user's switch only need be deciphered D0 and D6, so only need two kinds of frequency-selecting filters, centre frequency is respectively 1881HZ and 588HZ.The assurance signal of the D6 of frequency-selecting filter output as bistable data latch 74LS75, D0 is as the input data, like this when receiving digital command 1000001, D6 and D0 are 1 simultaneously, the Q output high level (logical one) of latch, after command signal finished, D6 became 0, and Q output is latched.D6 becomes the data before 0, still keeps high level (logical one).This state is kept down always.During command signal 1000000 that the user sends, D0 is 0.Refresh Data in the latch becomes 0, and Q output becomes low level (logical zero) and keeps behind order fulfillment.Convenient for circuit design, cut bank and instruction switch all take low level to connect, so export as switching controls with the Q of 74LS75.Four tunnel users are switched needs quadruplet foregoing circuit, shared 8 frequency-selecting filters.Image switching control and instruction switching controls need independent latch, also are 8 altogether, and every of 74LS75 comprises 4 latchs, so only use two.In Figure 10, to send instruction and all decipher for any 1 among 4 users via the frequency-selecting filter that integrated package LM567 constitutes, the IC1 centre frequency is 588HZ, its output 8 pin are received 74LS75 E01 end through phase inverter, make to guarantee signal.The IC2 centre frequency is 1881HZ, its output 8 pin are leaded up to NOR gate and are outputed to the D0 end of latch 74LS75, another road is to be passed to latch D1 end through phase inverter, latch Q0 outputs to instruction switching controls 1,2,3,4, Q1 output to image switching control 1 ', 2 ', 3 ', 4 ', other user.T is for forcing output, and T, R, S play expansion effect in parallel.Figure 10 is the instruction switch in user's switch, 4 users' 1,2,3,4 instruction is respectively by the reverse input end of 100K potentiometer to operational amplifier IC1, the signal of IC1 output is instructed the switch triode of switching controls to control, be added to the reverse input end of mixer amplifier IC2, its output termination emitter follower BG2, the emitter of this pipe passes to camera switcher by the compound audio signal of A point output by couple of conductor.Triode switch used herein, mixer amplifier and emitter follower, circuit is identical with corresponding part in the operation keyboard, only is the inputs of 7 road signals in the keyboard, has only 4 the tunnel herein.
Fig. 4 is the block diagram of camera switcher, the input B of camera switcher comes from the composite audio signal of user's switch output, it is divided into two-way, the signal that one tunnel conduct is switched is delivered to the instruction switch, another road is by command decoder M, be input to switch controller N, go control of video to switch X and instruction switch Y by switch controller N, switched selecting from the picture signal of 8 video cameras by video switcher X, instruction switch Y is to the camera control unit output order of appointment.Camera switcher is connected the picture signal of specifying video camera output by instruction, also operation instruction signal and corresponding camera control unit is connected simultaneously.Figure 12 is instruction decoding and control switching circuit.Four frequency-selecting filters are deciphered D0, D1, D2 and D5 respectively, integrated package LM567.D0, D1 and D2 give latch 74LS137 as data, make to guarantee signal with D5.The 3-8 decoder 74LS137 of band address latch have 8 independently export Y0, Y1, Y2 ..., Y7, guarantee signal E1, E2, E3 not simultaneously, 74LS137 makes differential responses to input signal A0, A1, A2, table 3 has illustrated the logic function of 74LS137.Guaranteeing that signal E1 is a high level, E2 and E3 are low level
The time, with input data A0, the corresponding low level that is output as of A1, A2, other output is high level, and low level is effectively output, and this moment is if other level is constant, E3 transfers high level to by low level, then output state is constant, enters latch mode, later on as long as E3 is constant, no matter how other level changes, output state all remains unchanged.If the low 3 figure place sign indicating numbers in the instruction are 001,74LS137 output 1 is low level, and other output is high level entirely, and output state remains unchanged behind the order fulfillment.If the low 3 figure place sign indicating numbers 010 of instruction, output 2 is low level, and other output is high level entirely, and the control voltage that image switching and instruction are switched is connected related circuit.
Three timing circuit NE555(IC1, IC2, IC3) all be designed to monostable flipflop, IC2 triggers IC3 to D5 time-delay back and produces burst pulse, assurance signal E3 as 74LS137, its duration was so just thoroughly got rid of because the different chaotic possibilities of 74LS137 work that cause of frequency-selecting filter output time-delay much smaller than the instruction duration.
Form multistage surveillance in order to guarantee that camera switcher serial connection same more than two or two is used, at switching command in the duration, with 8 or allow the instruction switching controls export high level entirely,, can not pass to next stage to guarantee same instruction 8 tunnel all shutoffs of instruction output.With to produce the duration be switching pulse about 1.5 seconds along triggering IC1 behind the D5, make A point during this period of time be locked as low level in addition, any new instruction all can only be passed to next stage, in the face of the corresponding levels inoperative.
The work of frequency-selecting filter is finished with phase lock circuitry.Reaction speed is relevant with many factors, even receive command signal simultaneously, because each phase lock circuitry operating frequency difference, output delay time is also different.For 74LS137 is worked on request reliably, can not be directly with the D5 signal of decoding output as guaranteeing signal, but postpone square wave that the back produces as the assurance signal with its pulse front edge, time chart is seen Figure 13.Frequency-selecting filter output D0, D1, D2 and D5, monostable flipflop output 1., 2., 3. and the time relationship available waveforms explanation of A, the conversion of B level point.Receive instruction during t0, D0, D1, D2 and D5 change low level into by high level in succession, and at this moment because of D is a low level, so A becomes high level by low level, B becomes low level by high level, and the negative saltus step of B triggers IC2 and makes 2. by the low high level that transfers to.Behind T1 after a while, IC2 recovers when t1,2. becomes low level again, and negative saltus step 2. triggers IC3, makes 3. by the low high level that transfers to, and behind T2 after a while, IC3 recovers when t2,3. becomes low level again again.
The instantaneous command signal of t3 finishes, and D5 becomes high level again by low level, and A becomes low level by high level, and the negative saltus step of this of A can trigger IC1, makes 1. to be become high level and lasted till that always t4 recovers again by low level.During this period of time in the T3,1. keep high level to t4 at t3, A is locked as low level, so even during this period of time receive new command signal, D5 becomes low level once again, other each level point can not change.
Fig. 5 is the block diagram of camera control unit, and signal is by command decoder M(Figure 15) remove to control controlled device drive circuit Q.Figure 16 is the drive circuit of camera control unit, presses the camera control unit output order and handles The Cloud Terrace change orientation and luffing angle, regulates lens focus and focal length, switch lens aperture, camera power supply and auxiliary device.The 1-8 of A is the positive action control signal, and 1 of B '-8 ' is the counteragent control signal, and C connects The Cloud Terrace, and F connects DC power supply, and P connects camera lens, and R provides AC power for power consumption equipment.Figure 14 is the circuit diagram of camera control unit.The action of the positive and negative both direction of camera control unit by two the cover fully independently the identity logic circuit finish.D3 is 1 o'clock, carries out positive operation; D4 is 1 o'clock, carries out reverse operating; D3 and D4 were failure to actuate in 0 o'clock.Normal condition can not be carried out the operation of positive and negative both direction simultaneously, so D3 and D4 can not be 1 simultaneously, the circuit of deciphering of D0, D1, D2 can a public cover, only need 5 kinds of frequency-selecting filters altogether, D0, D1 and the D2 of frequency-selecting filter output give two 74LS138 simultaneously as data, and D3 and D4 are used separately as their assurance signal.
3-8 decoder 74LS138 have 8 independently export Y0, Y1 ..., Y7, as the output of camera control unit numbering, Y0 is i.e. the 8 tunnel output of 8-.As input triad data A0, A1, A2, and when guaranteeing that signal is suitable, with the corresponding low level that is output as of input data, other output is high level, and low level be effectively to export; If guarantee signal improper, then all outputs are high level, just no-output.74LS138 has three to guarantee input E1, E2 and E3, and E1 and E2 are that low level is effective, and E3 is that high level is effective, the D3 of frequency-selecting filter output gives the E3 of IC1 and the E2 of IC2 simultaneously, and D4 gives the E2 of IC1 and the E3 of IC2 simultaneously, have only when D3 be 1, D4 is that 0 o'clock IC1 just has output, D4 is 1, and D3 is that 0 o'clock IC2 just has output, even because artificial misoperation, supress two key buttons that keyboard is established simultaneously, D3, D4 are 1 simultaneously, and camera control unit is output not, also just can not cause any consequence.
The phase lock circuitry that frequency-selecting filter is formed with integrated package LM567, the response speed of phase lock circuitry is relevant with many factors, even all conditions is all identical, because frequency of phase locking difference, output delay time is also different, even several filters are received command signal simultaneously, owing to represent different digital frequency differences, the output pulse front edge is impossible consistent in time.If directly give 74LS138 filter output, confusion must take place in circuit working, and whole system will not have practical value.
In order to address this problem, at first be to guarantee to decipher the filter lag output of high 4 bit codes in the filter of deciphering low 3 bit codes; For isotopic number sign indicating number assigned frequency not the time, specially allow the high more digital frequency of figure place low more.D0 frequency the highest (1881Hz), D6 frequency minimum (588Hz) is exactly this reason.The output filter capacitor of LM567 directly influences output delay time, and the filter corresponding with D3, D4 uses 10u electric capacity, also is for this purpose with D0, D1, filter that D2 is corresponding with 4.7u electric capacity.
After necessarily lagging behind D0, D1 as data, D2 as the D3 that guarantees signal and D4, pass through the OR-NOT circuit among the figure again, just guaranteed A0, A1, A2 and E1, the E2 consistency in time of 74LS138.
The present invention has realized with couple of conductor parallel convey 8 bit word instructions, command signal is switched easily, because it represents 128 independent switch instructions with 7 bit sign indicating numbers, the remote control parameter is many (for example controls the ON/OFF of 64 parameters, forward/back, lifting/lowering etc.), because there is the 8th figure place sign indicating number to give over to standby, can increase to 256 once enable number of instructions, the instruction of switching command signal is also included among 128 instructions, so just realized to many different field apparatus centralized control, and only needed an instruction signal generator that it is low to have saved the efficient of bringing with large operation platform and multiple conducting wires transmission, decay is big, the cost height, shortcomings such as circuit complexity are the parallel convey data because of it again, interference free performance is stronger than serial transfer significantly, improved the quality of system, simple to operate, therefore can large-scale popularization use.
Claims (4)
1, a kind of closed-circuit television system, by video camera and auxiliary equipment (The Cloud Terrace and camera lens) A, camera control unit B, camera switcher C, user's switch D, monitor and (or) magnetic recording equipment E, operation keyboard G and cable formed, be it is characterized in that:
A. between the equipment by special single cable connection, comprise high frequency coaxial line and two audio wires in the cable; The coaxial line of picture signal in cable of video camera output passes to camera switcher, pass to user's switch through coaxial line again after selecting to switch, finally pass to the monitor of monitoring terminal, the audio wire of the control signal that the operation keyboard of monitoring terminal sends in cable passes to user's switch, user's switch is connected picture signal and this user's monitor according to the indication of control signal, and this user's control signal and camera switcher and camera control unit connection, the audio wire of all control signals in cable is by monitoring that end passes to controlled device;
B. except that operation keyboard, all devices does not all have any manual operation key button, all moves according to the instruction of control signal; Camera control unit drives the The Cloud Terrace left rotation and right rotation, changes the video camera luffing angle, regulates focusing, changes lens focus, switch camera masking and camera power supply according to instruction; User's switch turns on and off the picture signal of leading to different user according to instruction, and user's control signal and miscellaneous equipment are connected; Camera switcher is issued the user to the picture signal of appointment video camera according to instruction, also control signal is issued the appointment camera control unit simultaneously;
C. all devices all is digital control, and all instructions are binary digital code; Comprise the EIC equipment identification code of indication distinct device action and the numeric data code of the different movement contents of explanation in the instruction code;
D. represent that the control signal of different binary digital codes instruction only uses a pair of audio wire parallel transmission;
2,, it is characterized in that expressing the instruction that all closed circuit television equipments are controlled with 7 bit binary number codes according to the described closed-circuit television system of claim 1.
3, according to claim 1,2 described closed-circuit television systems, it is characterized in that all controlled equipment all only need decipher number relevant with it in the instruction code, needn't decipher whole 7 figure place sign indicating numbers; As long as user's switch is deciphered 2 in 7, as long as camera switcher is deciphered 4, as long as camera control unit is deciphered 5 figure place sign indicating numbers.
4, a kind of control method of closed-circuit television system is characterized in that producing and representing the method for 8 binary code command signals and to the method for deciphering of sort signal with the couple of conductor parallel convey with a kind of:
A. the instruction signal generator in the operation keyboard is meant the audio frequency sinusoidal oscillator of 8 different frequencies, and 8 frequencies that they produce are represented 8 bit sign indicating numbers respectively;
B. the keyboard matrix circuit of being made up of diode network is when the different operating button is connected and line output 8 bit sign indicating number D0, D1 ..., D7;
C. the D0 of keyboard matrix circuit output, D1 ..., D7 delivers to instruction signal generator, controls the output of 8 audio frequency oscillators respectively, and these 8 controlled output signals are given mixer amplifier simultaneously, and mixed composite signal is exported through emitter follower.Having or not of certain frequency represents that promptly certain figure place sign indicating number is 1 or is 0 in the output signal;
D. deciphering with 8 centre frequency frequency-selecting filters corresponding with frequency of oscillation of composite audio signal finished, in parallel the filter input, make them receive composite audio signal simultaneously, corresponding filter just has output when having a certain frequency in the input signal, and 8 filters outputs have just recovered 8 parallel-by-bit binary numerals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90106845 CN1017583B (en) | 1990-08-20 | 1990-08-20 | Closed-circuit television controlled by two conducting wires |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90106845 CN1017583B (en) | 1990-08-20 | 1990-08-20 | Closed-circuit television controlled by two conducting wires |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1049260A true CN1049260A (en) | 1991-02-13 |
| CN1017583B CN1017583B (en) | 1992-07-22 |
Family
ID=4880294
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90106845 Expired CN1017583B (en) | 1990-08-20 | 1990-08-20 | Closed-circuit television controlled by two conducting wires |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1017583B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1051898C (en) * | 1997-05-05 | 2000-04-26 | 沈来沛 | Non-whole picture inhibiting TV monitoring system with bidirectional field counter code |
| CN105554617A (en) * | 2016-03-01 | 2016-05-04 | 敲敲科技（北京）有限公司 | Earphone system |
-
1990
- 1990-08-20 CN CN 90106845 patent/CN1017583B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1051898C (en) * | 1997-05-05 | 2000-04-26 | 沈来沛 | Non-whole picture inhibiting TV monitoring system with bidirectional field counter code |
| CN105554617A (en) * | 2016-03-01 | 2016-05-04 | 敲敲科技（北京）有限公司 | Earphone system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1017583B (en) | 1992-07-22 |
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