| Nowadays, the computer network has been applied in various industries. But sometimes data transfer mess up or even the communication is blocked ,which may cause huge economic lose, because of unreasonable design, incorrect implementation ,natural factors and so on. So it is important for net maintenance workers to find out where the net cable problem is and think out how to solve it as soon as possible.The twisted-pair test module is essence of the projet"Portable Network Trouble Testing Instrument"carrying out following functions, broken point located and wire map test, but it still has some defects. Based on existent design ,this article focuses on developing the systemic stability through perfecting test function and design a power module with small volume,low power consumption. The author's main works had listed below:1. Contraposed to the shortages of unstable test results and inadequate test channels in broken point test, improved the circuit of measure pulse wide and increased the test channels from one to four.2. Due to the wire map test circuit could not detect short connect pair and the result influenced by the noise so much,Researched the method of wire map test,design new circuit to detect short connect pair, that make the wire map test inextenso; eliminate the affect of noises to the test results,that make the test results more reliable.3. In view of the emission level of disturbance source exceeded the set level in the EMC test, according to the test report, the author did a simple test instrumentation to analyzed the reason that bring on the disturbance, improved the placement and route of PCB and sloved the EMC problem.4. Acquire more trustworthy data transfer by improving the design of serial communication program, FLASH burn program and DSP bootloader and adding checkout.5. Designed a mulit output power module according to the system's request for voltage and current, at the same time, realized battery charge manage circuite and on-off control circuite. |
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