CN104457545B - The whether isometric system and method detected of each cable in a kind of group to cable - Google Patents
The whether isometric system and method detected of each cable in a kind of group to cable Download PDFInfo
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- CN104457545B CN104457545B CN201410852395.8A CN201410852395A CN104457545B CN 104457545 B CN104457545 B CN 104457545B CN 201410852395 A CN201410852395 A CN 201410852395A CN 104457545 B CN104457545 B CN 104457545B
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Abstract
The invention discloses the whether isometric system detected of each cable in a kind of group to cable, including：Signal generator, oscillograph, for the cable group to be detected of differential transfer, it is made up of the first radio frequency coaxial cables and the second radio frequency coaxial cables；Wherein, first radio frequency coaxial cables positive pole respectively with signal generator, the trigger signal port of oscillograph are connected, and second radio frequency coaxial cables negative pole respectively with signal generator, the measured signal port of oscillograph are connected.The invention also discloses a kind of whether isometric method detected of each cable in group to cable, two radio frequency coaxial cables can be detected simultaneously so that the present invention has, improve the efficiency of detection, reduce the error produced because repeatedly measuring, to obtain more preferable accuracy of detection, its other testing result is more easy to obtain, so as to enormously simplify detection difficulty.
Description
Technical field
The present invention relates to the length detection between a kind of cable used in the case of the differential transfer.More specifically,
Detected the present invention relates to whether the length between a kind of radio frequency coaxial cables used in the case of the differential transfer is isometric
System and detection method.
Background technology
Differential transfer is a kind of technology of signal transmission, is different from the way of a traditional piece ground wire of a signal wire, poor
Transmission is divided all to transmit signal in this both threads, the amplitude of the two signals is equal, opposite in phase, is transmitted in this both threads
Signal is exactly differential signal.Differential signal have strong antijamming capability, can effectively suppression electromagnetic interference, sequential accurate positioning etc. it is excellent
Point, but be logical zero or logic 1 because signal receiving end compares the difference of the two voltages judge that transmitting terminal sends, because
This is of crucial importance.
Radio frequency coaxial-cable refers to there are two concentric conductors, and conductor and screen layer share the cable in same axle center, its
For in differential transfer, it to carry out isometric control to reach to differential signal in high speed transmission of signals, as in differential transfer
Two radio frequency coaxial-cables of signal pumped (conveying) medium must be isometric as far as possible, in order to ensure the precision of differenceization signal transmission, two
The transmission time difference of root radio frequency coaxial-cable will be controlled in psec rank, therefore provides higher want to the error in length of cable
Ask.
In the prior art, for the whether isometric time domain typically used of radio frequency coaxial-cable for realizing differential transfer
Reflection technology, includes producing the time step voltage propagated along transmission line by the technology.With oscillograph detection come self-impedance
Reflection, measurement input voltage and reflected voltage ratio, so as to calculate discontinuous impedance.It is continuously special using the impedance of RF cable
Property, continuous resistance region and impedance jump node are found out on oscillograph to calculate during transmission of the signal on RF cable
Between, the length of RF cable is calculated again by the transmission speed of RF cable.This technology is in measurement due to there is node
More, the hop region shown on oscillograph is more, when RF cable is shorter is difficult to tell signal in radio frequency when especially
Transmission time region on cable, significantly increases the difficulty of measurement；Simultaneously because the technology uses Time Domain Reflectometry device,
Therefore measurement can only obtain transmission time of the differential signal in a radio frequency coaxial-cable every time, therefore be needed for differential transfer
Radio frequency coaxial-cable group, it is necessary to be measured twice, by the biography of each radio frequency coaxial-cable in obtained radio frequency coaxial-cable group
The defeated time is compared, and passage time difference is to judge whether it is isometric, and measurement is wasted time and energy, and because measuring twice, because of instrument
The error that the produces when error of device itself or operator's operation and added up so that error is increased, last measurement essence
Degree does not reach requirement.
The content of the invention
It is an object of the invention to solve at least the above and/or defect, and provide at least will be described later excellent
Point.
It is a still further object of the present invention to provide a kind of detecting system, it can be carried out to two radio frequency coaxial cables simultaneously
Detection, and relative to traditional detecting system, its testing result is more easy to obtain, so as to enormously simplify detection difficulty.
A further object of the invention is the detection method by offer, improves the efficiency of detection, is reduced because of repeatedly survey
The error measured and produced, to obtain more preferable accuracy of detection.
In order to realize according to object of the present invention and further advantage there is provided each cable in a kind of group to cable whether
The isometric system detected, including：
Signal generator for producing differential square signals；
Oscillograph；
For the cable group to be detected of differential transfer, it is by the first radio frequency coaxial cables and the second radio frequency coaxial cables group
Into；
Wherein, first radio frequency coaxial cables positive pole respectively with signal generator, the trigger signal port of oscillograph
Connection, second radio frequency coaxial cables negative pole respectively with signal generator, the measured signal port of oscillograph are connected；It is described
Signal generator sends differential square signals, and the oscillograph receives the signal by cable group to be detected transmission and in oscillograph
On show respective waveforms, and judge by the way that whether the waveform isometric to cable group to be detected.
Preferably, wherein, the oscillograph is real-time oscilloscope, and the real-time oscilloscope is set to edging trigger side
Formula.
Preferably, wherein, the trigger signal of the real-time oscilloscope and measured signal are set to AC coupled mode, and
The trigger signal level of the real-time oscilloscope is set to 0V.
The purpose of the present invention can also be further by using to the whether isometric side detected of each cable in cable group
Method realizes that this method includes the signal generator and sends differential square signals；The cable group to be detected is to differential square
Signal is transmitted, and the oscillograph receives the differential square signals of cable group transmission to be detected and goes out phase by oscilloscope display
Waveform is answered, and the position in the X-axis of oscillograph is fallen according to edge midpoint in the waveform, to first in cable group to be detected
Radio frequency coaxial cables and whether the second radio frequency coaxial cables are isometric is judged, side in the waveform shown as described on oscillograph
Fall along midpoint in the origin of coordinates of oscillograph, then judge that the first radio frequency coaxial cables and the second radio frequency coaxial cables are isometric, it is no
Then judge Length discrepancy.
Preferably, wherein, edge midpoint falls the origin of coordinates in oscillograph in the waveform shown on the oscillograph
Left side, then the first radio frequency coaxial cables are longer than the second radio frequency coaxial cables.
Preferably, wherein, edge midpoint falls the origin of coordinates in oscillograph in the waveform shown on the oscillograph
Right side, then the first radio frequency coaxial cables are shorter than the second radio frequency coaxial cables.
Preferably, wherein, first radio frequency coaxial cables and the second RF coaxial line Length discrepancy, the then oscillograph
On in the waveform that shows edge midpoint with the origin of coordinates causing apart from Td for the cable group length difference to be detected in X-axis
Transmission time difference, it can thus be concluded that the length difference between the cable group to be detected.
Preferably, wherein, the length difference between the cable group to be detected can be obtained by the following formula：
Ld=Td/Pd；
Wherein, the Ld is the length difference between cable group to be detected, and its unit is cm；The Td is the transmission measured
Time difference, its unit is ps, and the Pd cables spread speed, its unit itself is ps/cm.
The present invention at least includes following beneficial effect：The detecting system of the present invention can be simultaneously to two radio frequency coaxial cables
Detected, and relative to traditional detecting system, its testing result is more easy to obtain, so as to enormously simplify detection difficulty.
The present invention improves the efficiency of detection by isometric radio frequency coaxial cables detection method simultaneously, reduces because of repeatedly survey
The error measured and produced, to obtain more preferable accuracy of detection.
Further advantage, target and the feature of the present invention embodies part by following explanation, and part will also be by this
The research and practice of invention and be understood by the person skilled in the art.
Brief description of the drawings
Fig. 1 is the structural representation of the whether isometric system detected of each cable in a kind of group to cable of the invention；
Fig. 2 obtains to be used in the present invention to the detection method of the whether isometric system detected of each cable in cable group
Instrumentation plan；
Fig. 3 is the whether isometric system calibration schematic diagram detected of each cable in a kind of group to cable of the present invention.
Embodiment
The present invention is described in further detail below in conjunction with the accompanying drawings, to make those skilled in the art with reference to specification text
Word can be implemented according to this.
It should be appreciated that such as " having ", "comprising" and " comprising " term used herein do not allot one or many
The presence or addition of individual other elements or its combination.
Fig. 1 shows a kind of way of realization according to the present invention, including：
Signal generator 10 for producing differential square signals, it is mainly special using the opposite in phase of differential square signals
Property,
Oscillograph 20；Its mainly by observation waveform thereon to carry out the cable in cable group to be detected whether etc. progress
Row judges；
For the cable group 30 to be detected of differential transfer, it is by the first radio frequency coaxial cables 31 and the second radio frequency coaxial cables
32 compositions；
Wherein, the triggering of the positive pole, oscillograph 20 of first radio frequency coaxial cables 31 respectively with signal generator 10 is believed
The connection of number port, second radio frequency coaxial cables 32 negative pole respectively with signal generator 10, the measured signal of oscillograph 20
Port is connected；The signal generator 10 sends differential square signals, and the oscillograph 20, which is received, passes through cable group 30 to be detected
The signal of transmission simultaneously shows respective waveforms, and whether isometric to cable group 30 to be detected by the waveform on oscillograph 20
Judged.Using the opposite in phase characteristic of differential square signals, the differential square signals that signal generator 10 is produced are being passed through
After isometric coaxial radio-frequency cable transmission to be detected, signal all the way is regard as the trigger signal of oscillograph 20, another road signal conduct
The measured signal of oscillograph 20；Then it is whether former with coordinate in oscillograph using the edge midpoint of the waveform of 20 displays on oscillograph
Whether point is overlapped, isometric to judge the first radio frequency coaxial cables and the second radio frequency coaxial cables in cable group to be detected.Using
This scheme have can once detect two radio frequency coaxial cables and directly by the waveform signal that is shown on observation oscilloscope just
The whether isometric benefit of two radio frequency coaxial cables can be judged, the error brought because repeatedly measuring is solved cumulative not
Sharp part.Also, this mode is a kind of explanation of preferred embodiments, but is not limited thereto.
In another embodiment, the oscillograph 20 is real-time oscilloscope, and the real-time oscilloscope is set to edge and touched
Originating party formula.Caused using this scheme because transmission time difference is easier to obtain caused by two radio frequency coaxial cables Length discrepancies.
Also, this mode is a kind of explanation of preferred embodiments, but is not limited thereto.
In another embodiment, the trigger signal of the real-time oscilloscope and measured signal are set to AC coupled side
Formula, to treat that two radio frequency coaxial cables mode of operations are the same, the resultant error that it is obtained is smaller, and described using this scheme
The trigger signal level of real oscillograph is set to 0V.Also, this mode is a kind of explanation of preferred embodiments, but is not limited to
In this.
Fig. 2 shows what is obtained according to the whether isometric method detected of each cable in a kind of group to cable of the invention
Instrumentation plan, this method includes the signal generator and sends differential square signals；The cable group to be detected is to difference side
Ripple signal is transmitted, and the oscillograph receives the differential square signals of cable group transmission to be detected and gone out by oscilloscope display
Respective waveforms, and the position in the X-axis of oscillograph is fallen according to edge midpoint in the waveform, in cable group to be detected
One radio frequency coaxial cables and whether the second radio frequency coaxial cables are isometric is judged, in the waveform shown as described on oscillograph
Edge midpoint falls in the origin of coordinates of oscillograph, then judges that the first radio frequency coaxial cables and the second radio frequency coaxial cables are isometric,
Otherwise Length discrepancy is judged.In the waveform shown on oscillograph using this scheme edge midpoint fall X-axis in oscillograph with
The difference value of the origin of coordinates is transmission time difference caused by the Length discrepancy of the isometric coaxial radio-frequency cable of difference, can quickly,
Easy calculates difference in length.Simultaneously because two RF cables are isometric, then signal is after same transmission delay
Trigger signal and measured signal are reached simultaneously, due to differential signal opposite polarity, the triggering mode of oscillograph are set to decline
The waveform as shown in waveform 1 in Fig. 2 can be observed along triggering (trailing edge triggering mode is similar, does not illustrate), now waveform 1
Edge midpoint should be at the origin of coordinates.In actually measurement, waveform edge midpoint is measured in the origin of coordinates i.e. it is believed that two
It is isometric that bar is tested radio frequency line.It has observation simple, it is easy to accomplish function.Also, this mode is a kind of preferred embodiments
Explanation, but be not limited thereto.
In another embodiment, edge midpoint falls the coordinate original in oscillograph in the waveform shown on the oscillograph
The left side of point, then the first radio frequency coaxial cables are longer than the second radio frequency coaxial cables, using this scheme penetrating due to trigger signal
Frequency line is longer, then delay of the delay of differential signal trigger signal in transmitting procedure also than measured signal is long, i.e.,
Measured signal first reaches oscillograph, and the triggering mode of oscillograph is set into trailing edge triggering, and (trailing edge triggering mode is similar, not
Illustrate), oscilloscope display waveform is as shown in Fig. 2 waveforms 2.The x-axis of the edge midpoint of waveform 2 and the origin of coordinates is apart from Td1
Transmission time difference caused by two tested length of cable differences, thus just can calculate the length difference of tested cable.It has
Directly obtain two radio frequency coaxial cables by observation whose short effect who grows, the simple and function that is easily achieved.Also, it is this
Mode is a kind of explanation of preferred embodiments, but is not limited thereto.
In another embodiment, edge midpoint falls the coordinate original in oscillograph in the waveform shown on the oscillograph
The right side of point, then the first radio frequency coaxial cables are shorter than the second radio frequency coaxial cables.Using this scheme penetrating due to trigger signal
Frequency line is shorter, then delay of the delay of differential signal trigger signal in transmitting procedure also than measured signal is short, i.e.,
Trigger signal first reaches oscillograph, and the triggering mode of oscillograph is set into trailing edge triggering, and (trailing edge triggering mode is similar, not
Illustrate), oscilloscope display waveform is as shown in Fig. 2 waveforms 3.The x-axis of the edge midpoint of waveform 3 and the origin of coordinates is apart from Td2
Transmission time difference caused by two tested length of cable differences, thus just can calculate the length difference of tested cable.It has
Directly obtain two radio frequency coaxial cables by observation whose short effect who grows, the simple and function that is easily achieved.Also, it is this
Mode is a kind of explanation of preferred embodiments, but is not limited thereto.
In another embodiment, first radio frequency coaxial cables and the second RF coaxial line Length discrepancy are then described to show
In the waveform shown on ripple device edge midpoint and the origin of coordinates in X-axis apart from Td be the cable group length difference to be detected
Caused transmission time difference, it can thus be concluded that the length difference between the cable group to be detected.Using this scheme obtain it is to be checked
Transmission time difference caused by cable group length difference is surveyed, it is relative in the prior art by finding out continuous impedance area on oscillograph
The method of domain and impedance jump node to calculate transmission time of the signal on RF cable, with simple and be easily achieved,
Error is small, workable advantage.Also, this mode is a kind of explanation of preferred embodiments, but is not limited thereto.
In another embodiment, the length difference between the cable group to be detected can be obtained by the following formula：
Ld=Td/Pd；
Wherein, the Ld is the length difference between cable group to be detected, and its unit is cm；The Td is to be detected to measure
The transmission time difference of cable group, its unit is ps, and the Pd cables spread speed, its unit itself is ps/cm.Using this side
The cable group length difference to be detected that case is obtained, it is simple with algorithm, it is easy to accomplish advantage.Also, this mode is one kind
The explanation of preferred embodiments, but be not limited thereto.
Due to may cause inside signal generator, oscillograph etc. in transmission time error, the present invention in cable group
The whether isometric system detected of each cable has following place to cause measurement error in testing：One is signal hair
Many strict 180 ° of differential signal phase difference that raw device is produced；Two be that oscillograph trigger signal Wiring port is filled to internal trigger
Put, and measured signal port terminals are differed to the transmission delay of internal signal sampled point.
It is inevitable in measurement process by the error that above-mentioned two situations occur is instrument itself error, and
Such measurement error is fixed error, therefore should first be calibrated to avoid judging by accident caused by such error before measuring.
Whether isometric the calibration steps of each cable system detected be as follows in a kind of group to cable in the present invention：
Step one, measured RF cable is replaced by the isometric difference cable of standard；
Step 2, is analyzed the measurement result that the isometric difference cable of standard is obtained, if as shown in figure 3, there is such as Fig. 3
Waveform shown in waveform 1, then illustrate that the system need not carry out calibration operation；If there is the waveform as shown in Fig. 3 waveforms 2,3, need
Calibration operation is carried out to system, specific method adjusts the triggered time of oscillograph trigger signal by the knob on oscillograph, directly
Calibration is completed as shown in waveform 1 to oscilloscope display waveform.
Step 3, keeps oscillograph current setting subsequently to be measured.
Number of devices and treatment scale described herein are the explanations for simplifying the present invention.To a kind of right of the present invention
The application of the whether isometric system and method detected of each cable, modifications and variations are to those skilled in the art in cable group
For be obvious.
As described above, the detecting system of the present invention, relative to detecting system of the prior art, it is believed using differential square
Number opposite in phase characteristic, after the transmission of differential pair isometric coaxial radio-frequency cable, signal all the way is used as to touching for oscillograph
Signal, another road signal as oscillograph measured signal.Two radio frequency coaxial cables can be detected simultaneously, and phase
It is simple to operate for traditional detecting system, it is time saving and energy saving, reduce the different errors and error produced because repeatedly measuring
It is cumulative so that the precision of its testing result finally obtained is higher.
Using the detection method of the detecting system of the present invention, relative to detection method of the prior art, it passes through oscillography
Edge midpoint falls the position in the X-axis of oscillograph in the waveform shown on device, just can be directly in cable group to be detected two
Whether root radio frequency coaxial cables are isometric to be judged, improves the efficiency of detection；Meanwhile, because of side in the waveform that is shown on oscillograph
Along midpoint and the origin of coordinates in X-axis apart from Td be transmission time difference caused by the cable group length difference to be detected so that
It by finding out continuous resistance region and impedance jump node on oscillograph to calculate signal relative to being penetrated in the prior art
The method of transmission time on frequency cable, with reading simple and being easily achieved, the characteristics of error is small, is thus more conducive to be treated
Detect the length difference between cable group.
Although embodiment of the present invention is disclosed as above, it is not restricted in specification and embodiment listed
With.It can be applied to this various suitable practical field completely., can be easily for those skilled in the art
Realize other modification.Therefore under the universal limited without departing substantially from claim and equivalency range, this practicality is not limited
In specific details and shown here as the legend with description.
Claims (8)
1. the whether isometric system detected of each cable in a kind of group to cable, it is characterised in that including：
Signal generator for producing differential square signals；
Oscillograph；
For the cable group to be detected of differential transfer, it is made up of the first radio frequency coaxial cables and the second radio frequency coaxial cables；
Wherein, first radio frequency coaxial cables positive pole respectively with signal generator, the trigger signal port of oscillograph are connected,
Second radio frequency coaxial cables negative pole respectively with signal generator, the measured signal port of oscillograph are connected；The signal
Generator sends differential square signals, and the oscillograph receives the signal transmitted by cable group to be detected and shown on oscillograph
Respective waveforms are shown, and judged by the way that whether the waveform is isometric to cable group to be detected.
2. as claimed in claim 1 to the whether isometric system detected of each cable in cable group, it is characterised in that described
Oscillograph is real-time oscilloscope, and the real-time oscilloscope is set to edging trigger mode.
3. as described in right wants 2 to the whether isometric system detected of each cable in cable group, it is characterised in that the reality
When oscillograph trigger signal and measured signal be set to AC coupled mode, and the trigger signal level of the oscillograph is set
For 0V.
4. a kind of system as any one of claims 1 to 3 is to the whether isometric side detected of each cable in cable group
Method, it is characterised in that the signal generator sends differential square signals；The cable group to be detected is entered to differential square signals
Row transmission；The oscillograph receives the differential square signals of cable group transmission to be detected and goes out corresponding ripple by oscilloscope display
Shape, and the position in the X-axis of oscillograph is fallen according to edge midpoint in the waveform, to the first radio frequency in cable group to be detected
Coaxial cable and whether the second radio frequency coaxial cables are isometric is judged, in the waveform shown as described on oscillograph in edge
Point falls in the origin of coordinates of oscillograph, then judges that the first radio frequency coaxial cables and the second radio frequency coaxial cables are isometric, otherwise sentence
Determine Length discrepancy.
5. detection method as claimed in claim 4, it is characterised in that edge midpoint in the waveform shown on the oscillograph
Fall the left side of the origin of coordinates in oscillograph, then the first radio frequency coaxial cables are longer than the second radio frequency coaxial cables.
6. detection method as claimed in claim 4, it is characterised in that edge midpoint falls in the waveform shown on the oscillograph
The right side of the origin of coordinates in oscillograph, then the first radio frequency coaxial cables are shorter than the second radio frequency coaxial cables.
7. the detection method as described in any one of claim 5 or 6, it is characterised in that first radio frequency coaxial cables and second
Edge midpoint and distance of the origin of coordinates in X-axis in RF coaxial line Length discrepancy, the then waveform shown on the oscillograph
Td is transmission time difference caused by the cable group length difference to be detected, it can thus be concluded that the length between the cable group to be detected
Difference.
8. detection method as claimed in claim 7, it is characterised in that length difference between the cable group to be detected can by with
Lower formula is obtained：
Ld=Td/Pd；
Wherein, the Ld is the length difference between cable group to be detected, and its unit is cm；The Td is the transmission time measured
Difference, its unit is ps, and the Pd cables spread speed, its unit itself is ps/cm.
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|---|---|---|---|
| CN201410852395.8A CN104457545B (en) | 2014-12-31 | 2014-12-31 | The whether isometric system and method detected of each cable in a kind of group to cable |
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| CN104457545B true CN104457545B (en) | 2017-07-18 |
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| CN108151641B (en) * | 2017-12-14 | 2020-08-18 | 北京无线电计量测试研究所 | Method and equipment for measuring length of radio frequency transmission line |
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| JP4071688B2 (en) * | 2003-05-12 | 2008-04-02 | ローム株式会社 | Vibration measuring method and apparatus |
| CN202126248U (en) * | 2011-06-29 | 2012-01-25 | 福建福硕线缆有限公司 | Synchronous measurement device of cable length |
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| CN202814349U (en) * | 2012-10-11 | 2013-03-20 | 上海谷元电气科技有限公司 | System for on-line monitoring of sag of overhead transmission line |
| CN103063148A (en) * | 2013-01-17 | 2013-04-24 | 中国电子科技集团公司第三十四研究所 | Measuring circuit and measuring method of optical cable length errors |
| CN103591895A (en) * | 2013-11-07 | 2014-02-19 | 中国电子科技集团公司第四十一研究所 | Optical fiber length measuring system and measuring method |
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2014
- 2014-12-31 CN CN201410852395.8A patent/CN104457545B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4071688B2 (en) * | 2003-05-12 | 2008-04-02 | ローム株式会社 | Vibration measuring method and apparatus |
| CN202126248U (en) * | 2011-06-29 | 2012-01-25 | 福建福硕线缆有限公司 | Synchronous measurement device of cable length |
| CN202676133U (en) * | 2012-03-09 | 2013-01-16 | 中国科学院西安光学精密机械研究所 | High-precision optical fiber length measuring system |
| CN202814349U (en) * | 2012-10-11 | 2013-03-20 | 上海谷元电气科技有限公司 | System for on-line monitoring of sag of overhead transmission line |
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