CN101706543B - Remote low-voltage cable sequencing device and remote low-voltage cable sequencing method - Google Patents

Abstract

The invention discloses a long-distance low-voltage cable sequencing device and a sequencing method. The sequencing device with a receiving and sending device is provided with an FPGA core module respectively connected to a connecting clip body, a liquid crystal display screen and a function switching button, and is generated in a sending mode. The OFDM modulated signal with line sequence information is sent to the cable to be tested; in the receiving mode, the OFDM modulated signal containing line sequence information on the cable to be tested is received, and the correct line sequence pair information is obtained after demodulation and decoding; The invention integrates the receiving and sending devices together without any reference point, the hardware connection is simple, and the use is extremely convenient. Based on FPGA chip design, using OFDM modulation and demodulation to transmit and identify digital line sequence signals, the transmission distance is long, the external circuit connection is greatly simplified, and some external signal conditioning modules in the prior art are removed, thereby improving the flexibility of the device. Easy to expand, up to 150-core cables can be measured at the same time.

Description

A long-distance low-voltage cable sequencing device and sequencing method

technical field

The invention relates to a low-voltage cable sequencing technology, in particular to a long-distance low-voltage cable sequencing device.

Background technique

At present, cable is an important transmission medium of informatization, and its application has penetrated into various fields. During the cable laying process, how to identify the intricate and complex cables at both ends of the long-distance cable laying has become a difficult problem in construction. Although multi-core cables can be distinguished by color codes, it is still difficult to effectively distinguish if there is more than one multi-core cable at the node, and it is even more difficult when the cable fails due to factors such as the surrounding environment, external force, rodent damage, corrosion and aging. Difficult to distinguish effectively. How to solve the intricate pairing and positioning of the wire sequences at both ends of multiple cables during the maintenance process is an urgent problem to be solved.

In the domestic market, equipment for pairing cable sequence mainly adopts cable resistance network measurement or public ground wire measurement. The patent with the publication number CN89204959.6 and the name "Digital Display Cable Alignment Instrument" uses resistors of different values to connect them into a star structure. When the probe is connected to the other end of the core wire, the core wire number is calculated according to the resistance network. The disadvantage is that there is a common reference ground wire at both ends of the cable under test. The publication number is CN93213630.3, and the patent titled "cable alignment device" uses digital circuits to generate scanning pulse signals and electronic switch arrays to realize cable alignment. It uses unmodulated voltage or current signals for measurement. The defect is that when the cable distance Long time and severe signal loss will lead to measurement failure. The publication number is CN200810136691.2, and the title is "Multi-core cable sequencing method and device based on frequency modulation digital coding". The patent uses digital frequency modulation method to realize signal transmission. The disadvantage is that a reference cable needs to be selected, and only one pair of cables can be measured each time. , and the transmission distance is short, and the anti-interference ability is poor.

Contents of the invention

The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a long-distance low-voltage cable sequencing device that can simultaneously measure multiple core cables without any reference line. Another purpose of the present invention is to provide a reliable A long-distance low-voltage cable sequencing method with strong anti-interference ability.

The technical solution adopted by the sequencing device of the present invention is: the sequencing device is externally connected to the connecting clip body, and the outer surface of the sequencing device is provided with a liquid crystal display, a function switching button and a working status indicator light, and a sequencing device with a receiving and transmitting device is provided with a connecting device respectively. The FPGA core module connected with the clip body, the liquid crystal display screen and the function switch button, the FPGA core module includes a serially connected encoding/decoding module, OFDM modulation/demodulation module, comparison shaping module and signal input and output module, and the function control module is connected with the The modules are connected; the function control module controls the flow direction of the signal received or sent by the sequencing device.

The technical solution adopted by the sequencing method of the present invention has the following steps: switch the function switching button, and set the receiving and sending devices to the receiving mode or the sending mode respectively; in the sending mode, the encoding/decoding module encodes the line sequence signal and inputs it into the OFDM The modulation/demodulation module performs modulation to generate an OFDM modulated signal with line sequence information, which is processed by the comparison shaping module and sent to the cable to be tested through the signal input and output module; in the receiving mode, the signal input and output module receives the signal to be tested The OFDM modulated signal containing line sequence information on the cable, after being processed by the comparison shaping module, demodulated by the OFDM modulation/demodulation module and decoded by the encoding/decoding module, the correct line sequence pair information is obtained; all obtained line sequence pairs The result is displayed on the LCD screen.

The beneficial effects of the present invention are:

1. Integrate the receiving and transmitting devices into one body, which can realize both the transmitter function and the receiver function. The two ends of the receiving and transmitting devices are connected in the same way as the cable, without any reference point. The hardware connection is simple and the use is extremely convenient.

2. Based on the FPGA chip design, the OFDM modulation and demodulation method is used to transmit and identify digital line sequence signals, the transmission distance is long, the external circuit connection is greatly simplified, and some external signal conditioning modules in the prior art are removed, thereby improving the performance of the device. Flexibility makes it easy to expand the device, and can measure up to 150 core cables at the same time.

3. The test device is small in size and convenient for on-site use.

Description of drawings

Fig. 1 is a schematic diagram of the appearance of the cable sequencing device of the present invention.

Fig. 2 is the functional block diagram of FPGA core module 4 inside Fig. 1;

Attachment 3 is the circuit schematic diagram of the cable sequence measuring device of the present invention.

In the figure: 1. Sequencing device; 2. Connecting clip; 3. LCD display; 4. FPGA core module; 5. Function switch button; 6. Working status indicator light; 7. Function control module; ; 9. OFDM modulation/demodulation module; 10. Comparison shaping module; 11. Signal input and output module.

Detailed ways

As shown in Figure 1, a receiving device and a transmitting device are installed inside the sequencing device 1, and the cable connection clip 2 of the receiving device and the transmitting device is externally connected to the sequencing device 1, and a liquid crystal display 3 and a function switching button 5 are arranged on the outer surface of the sequencing device 1 and working status indicator light 6. An FPGA core module 4 is also set inside the sequencing device 1, and the connecting clip body 2, the liquid crystal display 3, and the function switching button 5 are respectively connected to the FPGA core module 4, and the sequencing device 1 can have a transmitter function through the function switching button 5 or the receiver function, respectively connect the connecting clamp body 2 of the transmitter function or the receiver function to both ends of the cable to be tested. At this time, the liquid crystal display 3 of the receiving device displays the corresponding line sequence pair.

As shown in Figure 2, the FPGA core module 4 includes a function control module 7, and the function control module 7 is respectively connected to the encoding/decoding module 8, the OFDM modulation/demodulation module 9, the comparison shaping module 10 and the signal input and output module 11; the encoding/decoding module 8 , OFDM modulation/demodulation module 9, comparison and shaping module 10 and signal input and output module 11 are sequentially connected in series. The function control module 7 is used to control whether the sequencing device 1 is a receiving device or a sending device, so as to control the signal flow. In the sending mode, the encoding/decoding module 8 encodes the line sequence signal, sends it to the OFDM modulation/demodulation module 9 for modulation, processes it through the comparison shaping module 10, and sends it to the cable to be tested through the signal input and output module 11. In the receiving mode, the signal input and output module 11 receives the OFDM modulated signal containing line sequence information on the cable to be tested, processed by the comparison and shaping module 10, demodulated in the OFDM modulation/demodulation module 9, and processed in the encoding/decoding module 8 to get the correct line sequence pair information.

As shown in FIG. 3 , U1 is an FPGA chip EP1C6QC240 as the FPGA core module 4 . The slot J1 is connected to U1, and is directly connected to the 1-20 pins of J1 through pins 217-228, 233-240 of U1, and the connecting clip body 2 is connected to the other end of the slot J1. The LCD screen 3 is connected to the slot J2, the 73~85 pins of U1 are respectively connected to the 4~16 pins of the slot J2, the 18 pins of the slot J2 are connected to the 1 pin of the resistor R2, and the Pin 2 is connected to pin 3 of slot J2, pin 3 of slot R2 is connected to power supply VCC3.3V, pins 17 and 19 of slot J2 are connected to VCC3.3V. Function switch button 5 is S1, pin 1 of S1 is connected to pin 216 of U1, and pin 2 of resistor R1 is connected, pin 1 of resistor R1 is connected to GND, pin 2 of S1 is connected to VCC3.3V . Working status indicator light 6 is D1 and D2, pins 63 and 62 of U1 are connected with pins 2 of D1 (the first LED lamp) and D2 (the first LED lamp) respectively, pins 1 of D1 and D2 are connected with the resistor R3 Pin 1 is connected, and pin 2 of resistor R3 is connected to VCC3.3V.

When the present invention is tested, first connect the connecting clips 2 on the two sets of receiving and sending devices to the two ends of the cable to be tested in the sequencing device 1, and then switch the two sets of devices to the receiving mode by switching the function switching button 5 or send mode. The FPGA core module 4 of the device in the transmission mode generates an OFDM modulated signal with a line sequence, which is sent to the cable to be tested, that is, the encoding/decoding module 8 encodes the line sequence signal, and inputs it to the OFDM modulation/demodulation module 9 for modulation to generate The OFDM modulated signal with line sequence information is processed by the comparison and shaping module 10, and sent to the cable to be tested through the signal input and output module 11. The device in the receiving mode receives the OFDM modulated signal from the cable to be tested, demodulates and decodes it, that is, the signal input and output module 11 receives the OFDM modulated signal containing line sequence information on the cable to be tested, and processes it through the comparison and shaping module 10 1. After the OFDM modulation/demodulation module 9 demodulates and the encoding/decoding module 8 decodes, the correct line sequence pair information is obtained, and finally all the obtained line sequence pair information results are displayed on the liquid crystal display 3 .

Claims (1)

1. A long-distance low-voltage cable sequencing device, the sequencing device (1) is externally connected to the connecting clip (2), and the outer surface of the sequencing device (1) is provided with a liquid crystal display (3), a function switching button (5) and a working status indicator The lamp (6) is characterized in that: a sequencing device (1) with a receiving and sending device is provided with an FPGA core module connected to the connecting clip body (2), liquid crystal display (3) and function switching button (5) respectively (4), the FPGA core module (4) includes a serially connected encoding/decoding module (8), OFDM modulation/demodulation module (9), comparison shaping module (10) and signal input and output module (11), function control The module (7) is respectively connected with the encoding/decoding module (8), the OFDM modulation/demodulation module (9), the comparison shaping module (10) and the signal input and output module (11); the function control module (7) controls the sequencing device ( 1) is the signal flow direction received or sent.

Images