CN103994713A - Novel cable length measuring method - Google Patents
Novel cable length measuring method Download PDFInfo
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- CN103994713A CN103994713A CN201410265881.XA CN201410265881A CN103994713A CN 103994713 A CN103994713 A CN 103994713A CN 201410265881 A CN201410265881 A CN 201410265881A CN 103994713 A CN103994713 A CN 103994713A
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Abstract
The invention provides a novel cable length measuring method. The method comprises the following steps that A, a corresponding relation between the pulse number and the length of a measured cable is set, and is stored in a central processing module; B, the central processing module sends a reference pulse to a measured cable and a pulse difference generating module, and meanwhile a pulse counting module is started for beginning counting; C, the reference pulse sent to the measured cable is processed by a first processing module to generate a capacitance effect pulse and is sent to the pulse difference generating module; D, according to the pulse difference generating module, the reference pulse is compared with the capacitance effect pulse so as to obtain the pulse difference, and meanwhile the pulse counting module stops counting; E, the pulse counting modules counts the pulse number of the pulse difference and sends the pulse number to the central processing module; F, the central processing module calculates the length of the measured cable according to the corresponding relation between the pulse number and the length of the measured cable. According to the method, the measurement of the cable length can be achieved by counting the pulse number of the pulse difference, the measuring error is reduced, and accuracy is improved.
Description
Technical field
The present invention relates to communications cable measurement of length method, relate more specifically to a kind of method of step-by-step counting survey length of cable.
Background technology
What the instrument of at present, the communications cable being tested generally adopted is pulse reflection method.Pulse reflection method is used the test signal of burst pulse as transmitting, and this signal is propagated in cable, and in the time running into impedance discontinuity point, pulse signal is reflected back toward transmitting terminal.The overlapping portion of measuring the pulse of launching and be reflected back at signal sending end comprises how many full sized puless, just can calculate the mistiming of transmitting and the pulse signal that reflects, then the transmission speed in cable just can calculate the length of barrier point cable according to pulse.But the quality requirements of the method paired pulses waveform is higher, generally in pulse
Overlapping portion is to fade to low level by high level, and therefore we can produce certain error in the time adopting the method to measure.
Therefore, be necessary to provide a kind of method of measuring length of cable by calculating the number of pulse to overcome above-mentioned defect.
Summary of the invention
For above-mentioned prior art, technical matters to be solved by this invention is to provide a kind of Novel cable length measurement method, and this Novel cable length measurement method is measured length of cable to reduce measuring error by calculating the number of pulse, improves accuracy.
In order to solve the problems of the technologies described above, the invention provides a kind of Novel cable length measurement method, comprise the following steps:
A., corresponding relation between pulse number and tested length of cable is set and is stored in central processing module;
B. described central processing module sends a basic pulse to described tested cable and pulse difference generation module, and starting impulse counting module starts counting simultaneously;
C. the described basic pulse that is sent to described tested cable generates a capacity effect pulse and is sent to pulse difference generation module after the first processing module is processed;
D. described pulse difference generation module compares to obtain pulse difference by described basic pulse and described capacity effect pulse, and described pulse counter module stops counting simultaneously;
E. described pulse counter module is counted the pulse number of described pulse difference and described pulse number is sent to described central processing module;
F. described central processing module calculates the length of described tested cable according to the corresponding relation between described pulse number and tested length of cable.
Further improvement of the present invention is that described step B comprises step by step following:
B1. described central processing module sends a basic pulse to described tested cable and pulse difference generation module;
B2. start clock generator simultaneously;
B3. impulse meter starts counting simultaneously.
Further improvement of the present invention is that described step D comprises step by step following:
D1. described pulse difference generation module compares to obtain pulse difference by described basic pulse and described capacity effect pulse;
D2. stop clock generator simultaneously;
D3. impulse meter stops counting and count results is stored in to data latches simultaneously.
Further improvement of the present invention is, described pulse counter module comprises clock generator, impulse meter and data latches, and described clock generator and data latches interconnect with described impulse meter respectively; Described clock generator, for generation of clock information, described impulse meter, the clock information the poor pulse number of count pulse that produce for receiving described clock generator, described data latches, for storing described impulse meter count results.
Further improvement of the present invention is that described the first processing module comprises interconnective electronic switch U3 and U4, and a pin of described electronic switch U3 is connected to described pulse counter module, a pin ground connection of described electronic switch U4.
Further improvement of the present invention is that described pulse difference generation module is a Sheffer stroke gate.
Further improvement of the present invention is, described central processing module adopts Single-chip Controlling, comprise single-chip microcomputer U1 and working pulse circuit, described working pulse circuit, use for single-chip microcomputer U1 work for generation of working pulse, single-chip microcomputer U1 produces a basic pulse and outwards sends through its pin CNT-CLR.
Further improvement of the present invention is to adopt I2C bus protocol to communicate between pulse counter module and described central processing module.
Further improvement of the present invention is that described tested cable is coaxial cable, telephone wire, netting twine or other metallic cable.
Compared with prior art, Novel cable length measurement method of the present invention, in the time measuring tested cable, tested cable is connected in to the first processing module, central processing module sends a basic pulse to pulse difference generation module and the first processing module, the first processing module processes to obtain a capacity effect pulse to basic pulse, afterwards, pulse difference generation module compares to obtain pulse difference by basic pulse and capacity effect pulse, the pulse number that pulse counter module count pulse is poor also sends it to central processing module, central processing module will calculate according to the corresponding relation of the pulse number of pulse difference and interior stored pulse number and length of cable the length of tested cable, , the method has realized the measurement of length of cable by the poor pulse number of count pulse, reduced measuring error, has improved accuracy.
Brief description of the drawings
Fig. 1 is the structured flowchart of Novel cable length-measuring appliance of the present invention;
Fig. 2 is the circuit theory diagrams of Fig. 1;
Fig. 3 is the circuit theory diagrams of pulse counter module of the present invention;
Fig. 4 is the process flow diagram of Novel cable length measurement method of the present invention.
In figure, each component names is as follows:
10-central processing module;
The 11-the first processing module;
The 12-the second processing module;
13-pulse difference generation module;
14-pulse counter module;
141-clock generator;
142-impulse meter;
143-data latches.
Embodiment
Below in conjunction with brief description of the drawings and embodiment, the present invention is further described, and in accompanying drawing, similarly element numbers represents similar element.
As shown in Figure 1, Novel cable length-measuring appliance of the present invention comprises:
Central processing module 10, for arranging the corresponding relation between pulse number and tested length of cable and storing, send basic pulse and calculate length of cable;
The first processing module 11, for connecting described tested cable and receiving described basic pulse, and processes to obtain a capacity effect pulse to described basic pulse;
Pulse difference generation module 13, for receive and more described basic pulse and described capacity effect pulse to obtain pulse difference; And
Pulse counter module 14, carries out length computation for counting the pulse number of described pulse difference and described pulse number being sent to described central processing module 10.
Preferably, described pulse counter module 14 comprises clock generator 141, impulse meter 142 and data latches 143, and described clock generator 141 and data latches 143 are electrically connected mutually with described impulse meter 142 respectively; Described clock generator 141, for generation of clock information, described impulse meter 142, the clock information the poor pulse number of count pulse that produce for receiving described clock generator 141, described data latches 143, for storing described impulse meter 142 count results.Described Novel cable length-measuring appliance also comprises the second processing module 12, and described the second processing module 12 is for receiving described basic pulse and being sent to described pulse difference generation module 13.
Particularly, as shown in Fig. 2 and Fig. 3, described central processing module 10 adopts Single-chip Controlling, comprises single-chip microcomputer U1 and working pulse circuit; Working pulse circuit is made up of capacitor C 19, C20 and crystal oscillator X2, use for single-chip microcomputer U1 work for generation of working pulse, one end of one end of described capacitor C 19 and capacitor C 20 is connected ground simultaneously, the other end of described capacitor C 19 connects one end of described crystal oscillator X2 and the pin 31 of single-chip microcomputer U1 simultaneously, and the other end of described capacitor C 20 connects the other end of described crystal oscillator X2 and the pin 30 of single-chip microcomputer U1 simultaneously.Single-chip microcomputer U1 produces a basic pulse and outwards sends through its pin CNT-CLR.The first processing module 11 comprises electronic switch U3, U4, and 1,2,4,5,12,13,14,15 pins of described electronic switch U3 are electrically connected and are electrically connected with contactor JP1 respectively with 1,2,4,5,12,13,14,15 pins of described electronic switch U4 respectively; When described the first processing module 11 connects tested cable, it is upper that one end of cable is connected in described contactor JP1, and the other end of cable is open-circuit condition, pin 3 ground connection of described electronic switch U4; The basic pulse that described single-chip microcomputer U1 sends pin 3 from electronic switch U3 after electronic switch U4 returns.The second processing module 12 comprises Sheffer stroke gate U7C, resistance R 1, resistance R 2, resistance R 4, resistance R 5, electronic switch U2 and Sheffer stroke gate U7A, the basic pulse that single-chip microcomputer U1 sends is after Sheffer stroke gate U7C, enter the pin 1 of electronic switch U2 through resistance R 2, after resistance R 1, R4, enter the pin 12 of electronic switch U2, finally export by pin 3 and the pin 13 of electronic switch U2, the pulse of exporting through pin 13 is being exported after Sheffer stroke gate U7A.Pulse difference generation module 13 is a Sheffer stroke gate U7B, the pin 5 of Sheffer stroke gate U7B receives the basic pulse from the pin 3 of electronic switch U2,4 pin of Sheffer stroke gate U7B receive the capacity effect pulse from the pin 3 of Sheffer stroke gate U7A, and the pin 6 of Sheffer stroke gate U7B will be sent to pulse counter module 14 the pulse difference producing between capacity effect pulse and basic pulse.Described pulse counter module 14 comprises clock generator 141, impulse meter 142 and data latches 143, and described clock generator 141 and data latches 143 are electrically connected mutually with described impulse meter 142 respectively, described clock generator 141 comprises clock chip U5, capacitor C 1, C2, C35, resistance R 7, crystal oscillator X1, and described impulse meter 142 comprises step-by-step counting chip U6, and described data latches 143 comprises data latch chip U8, capacitor C 34 and polar capacitor C14, the pin 3 (CNT-CLK) of described clock chip U5 is electrically connected with the pin 10 (CNT-CLK) of described step-by-step counting chip U6, the pin 1 (CNT-CLK-EN) of described clock chip U5 is electrically connected with the pin 6 (CNT-CLK-EN) of described Sheffer stroke gate U7B, the pin 11 (CNT-CLR) of described step-by-step counting chip U6 receives the basic pulse that described single-chip microcomputer U1 produces, the pin 1 of described step-by-step counting chip U6, 12, 13, 15 respectively with the pin 8 of described data latch chip U8, 3, 4, 7 electrical connections, the pin 1 (U8-OE) of described data latch chip U8 is electrically connected with the pin 27 (U8-OE) of described single-chip microcomputer U1.
Particularly, between described pulse counter module 14 and described central processing module 10, adopt I2C bus protocol to communicate, but also can adopt other communication protocol to communicate.Particularly, tested cable is coaxial cable, telephone wire, netting twine or other metallic cable.
Taking tested cable as the netting twine that comprises 8 inner cores is as example, please refer to Fig. 1, Fig. 2 and Fig. 3, the principle of work of Novel cable length-measuring appliance of the present invention is as follows:
First one end of tested cable is inserted in the contactor JP1 of described Novel cable length-measuring appliance, the other end of cable is open-circuit condition, gating electronic switch U4 and electronic switch U3, due to pin 3 ground connection of electronic switch U4, between the inner core 1 of tested cable and inner core 2, can there is certain electric potential difference, thereby produce capacity effect, produce a basic pulse while gating electronic switch U2, U3, U4, clock chip U5, step-by-step counting chip U6 and data latch chip U8 by single-chip microcomputer U1 again, when electronic switch U2 receives after basic pulse, electronic switch U2 will close immediately, and the basic pulse that is sent to electronic switch U4 will be exported from the pin of electronic switch U3 3, produce capacity effect owing to being connected between the inner core 1 of tested cable of electronic switch U3 and U4 and inner core 2, therefore what export from the pin 3 of electronic switch U3 is a capacity effect pulse, described step-by-step counting chip U6 receives that basic pulse starts clock chip U5 simultaneously, and described step-by-step counting chip U6 starts counting, afterwards, capacity effect pulse exports the pin 4 of pulse difference generation module 13 (Sheffer stroke gate U7B) to through the pin 3 of Sheffer stroke gate U7A, and the process Sheffer stroke gate U7C of single-chip microcomputer U1 output, the basic pulse of electronic switch U2 and Sheffer stroke gate U7A will input to pulse difference generation module 13(Sheffer stroke gate U7B) pin 5, pulse difference generation module 13(Sheffer stroke gate U7B) capacity effect pulse and basic pulse are compared to obtain pulse difference, from pulse difference generation module 13(Sheffer stroke gate U7B) pin 6 export clock chip U5 to, described clock chip U5 stops, described step-by-step counting chip U6 stops counting also counting out the pulse number of pulse difference and sending it to single-chip microcomputer U1, last single-chip microcomputer U1 calculates the inner core 1 of tested cable with respect to the length of inner core 2 according to the corresponding relation of the pulse number of storing in the pulse number of this pulse difference and single-chip microcomputer U1 and length of cable, repeat above-mentioned steps, i.e. any two pins of gating electronic switch U3 and U4 constantly, measure respectively the length of inner core 1 with respect to inner core 3,4,5,6,7,8, then by single-chip microcomputer U1 calculating mean value to draw the length of inner core 1.In like manner, can measure the length of tested all the other inner cores of cable, finally realize the measurement of length of cable, reduce error, improve accuracy.
Correspondingly, as shown in Figure 4, the present invention also provides a kind of Novel cable length measurement method, comprises the following steps:
A., corresponding relation between pulse number and tested length of cable is set and is stored in central processing module 10;
B. described central processing module 10 sends a basic pulse to described tested cable and pulse difference generation module 13, and starting impulse counting module 14 starts counting simultaneously;
C. the described basic pulse that is sent to described tested cable generates a capacity effect pulse and is sent to pulse difference generation module 13 after the first processing module processes 11;
D. described pulse difference generation module 13 compares to obtain pulse difference by described basic pulse and described capacity effect pulse, and described pulse counter module 14 stops counting simultaneously;
E. described pulse counter module 14 is counted the pulse number of described pulse difference and described pulse number is sent to described central processing module 10;
F. described central processing module 10 calculates the length of described tested cable according to the corresponding relation between described pulse number and tested length of cable.
Preferably, described step B comprises step by step following:
B1. described central processing module 10 sends a basic pulse to described tested cable and pulse difference generation module 13;
B2. start clock generator 141 simultaneously;
B3. impulse meter 142 starts counting simultaneously.
Preferably, described step D comprises step by step following:
D1. described pulse difference generation module 13 compares to obtain pulse difference by described basic pulse and described capacity effect pulse;
D2. stop clock generator 141 simultaneously;
D3. impulse meter 142 stops counting and count results is stored in to data latches 143 simultaneously.
Novel cable length measurement method of the present invention, in the time measuring tested cable, tested cable is connected in to the first processing module, central processing module sends a basic pulse to pulse difference generation module and the first processing module, the first processing module processes to obtain a capacity effect pulse to basic pulse, afterwards, pulse difference generation module compares to obtain pulse difference by basic pulse and capacity effect pulse, the pulse number that pulse counter module count pulse is poor also sends it to central processing module, central processing module will calculate according to the corresponding relation of the pulse number of pulse difference and interior stored pulse number and length of cable the length of tested cable, , the method has realized the measurement of length of cable by the poor pulse number of count pulse, reduced measuring error, has improved accuracy.
As can be seen from the above description, Novel cable length-measuring appliance of the present invention and method, realized the measurement of length of cable by calculating the pulse number of pulse difference, reduced measuring error, improved accuracy.
Above content is in conjunction with concrete preferred implementation further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.
Claims (9)
1. a length of cable measuring method, is characterized in that, comprises the following steps:
A., corresponding relation between pulse number and tested length of cable is set and is stored in central processing module (10);
B. described central processing module (10) sends a basic pulse to described tested cable and pulse difference generation module (13), and starting impulse counting module (14) starts counting simultaneously;
C. the described basic pulse that is sent to described tested cable generates a capacity effect pulse and is sent to pulse difference generation module (13) after the first processing module processing (11);
D. described pulse difference generation module (13) compares to obtain pulse difference by described basic pulse and described capacity effect pulse, and described pulse counter module (14) stops counting simultaneously;
E. described pulse counter module (14) is counted the pulse number of described pulse difference and described pulse number is sent to described central processing module (10);
F. described central processing module (10) calculates the length of described tested cable according to the corresponding relation between described pulse number and tested length of cable.
2. length of cable measuring method as claimed in claim 1, is characterized in that, described step B comprises step by step following:
B1. described central processing module (10) sends a basic pulse to described tested cable and pulse difference generation module (13);
B2. start clock generator (141) simultaneously;
B3. impulse meter (142) starts counting simultaneously.
3. length of cable measuring method as claimed in claim 1, is characterized in that, described step D comprises step by step following:
D1. described pulse difference generation module (13) compares to obtain pulse difference by described basic pulse and described capacity effect pulse;
D2. stop clock generator (141) simultaneously;
D3. impulse meter (142) stops counting and count results is stored in to data latches (143) simultaneously.
4. the length of cable measuring method as described in claims 1 to 3 any one; it is characterized in that: described pulse counter module (14) comprises clock generator (141), impulse meter (142) and data latches (143), described clock generator (141) and data latches (143) interconnect with described impulse meter (142) respectively; Described clock generator (141), for generation of clock information, described impulse meter (142), be used for receiving clock information the poor pulse number of count pulse that described clock generator (141) produces, described data latches (143), for storing described impulse meter (142) count results.
5. the length of cable measuring method as described in claims 1 to 3 any one, it is characterized in that: described the first processing module (11) comprises interconnective electronic switch U3 and U4, and a pin of described electronic switch U3 is connected to described pulse counter module (14), a pin ground connection of described electronic switch U4.
6. the length of cable measuring method as described in claims 1 to 3 any one, is characterized in that: described pulse difference generation module (13) is a Sheffer stroke gate.
7. the length of cable measuring method as described in claims 1 to 3 any one, it is characterized in that: described central processing module (10) adopts Single-chip Controlling, comprise single-chip microcomputer U1 and working pulse circuit, described working pulse circuit, use for single-chip microcomputer U1 work for generation of working pulse, single-chip microcomputer U1 produces a basic pulse and outwards sends through its pin CNT-CLR.
8. the length of cable measuring method as described in claims 1 to 3 any one, is characterized in that: between pulse counter module (14) and described central processing module (10), adopt I2C bus protocol to communicate.
9. the length of cable measuring method as described in claims 1 to 3 any one, is characterized in that: described tested cable is coaxial cable, telephone wire, netting twine or other metallic cable.
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| CN201410265881.XA CN103994713A (en) | 2014-06-16 | 2014-06-16 | Novel cable length measuring method |
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| CN201410265881.XA CN103994713A (en) | 2014-06-16 | 2014-06-16 | Novel cable length measuring method |
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| CN105300263A (en) * | 2015-11-18 | 2016-02-03 | 长春轨道客车股份有限公司 | Wire length single-end measuring system based on low-voltage pulse reflection method |
| CN109254224A (en) * | 2018-11-13 | 2019-01-22 | 永州市诺方舟电子科技有限公司 | A kind of open circuit of the communications cable, misconnection line sequence measurement method and system |
| CN112434408A (en) * | 2020-11-12 | 2021-03-02 | 合肥阳光新能源科技有限公司 | Photovoltaic power station cable length optimization method, cable model selection method and device |
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