Design And Realization Of Long-Distance Transmission Module In Telemetry Equipment Of Universal Test Bench

In the experiment of ground testing to aircraft, the testers will control the device of acquisition and storage in the telemetry system. Before aircraft launching, the tester should be far away from the aircraft for safety. Therefore, we need long cable from 100m to 2000m, which connects the device of acquisition and storage with the measure-device on the ground. For the case, some common long communication method is compared. universal long distance transmission module is designed in the paper.At fist, overall design of long distance transmission module is introduced in the paper, which taking FPGA as main control logic, improving the flexibility of system. Parallel interface uses the technology of electrical current loop, which is easy, and works stably and reliably. Serial interface use the technology of LVDS, which has low power dissipation and high data transmission speed.Secondly, each interface of hardware circuit and logic timer is introduced in the paper. Parellel interface uses the circuit of photoelectric isolation, and gives the timer. Serial digital cable driver with adjustable outputs is used to enhancing the distance of data transmission. This system employs the two LVDS chips which can coordinate with the driver chips.Tirdly, The paper introduces the crucial technology in the design, including"warm-up"technology, tremble-deleting technology, matched resistance, and so on.All functions of the long-distance transmission module reach to the target and the requirement of general use, by using the combination-testing with the analogue-measured device. In the serial interface, the rate of the LVDS optical-fiber is 20M Byte/s, and transmission distance of it is 2000m. The rate of the LVDS twist-pair is 20M Byte/s, and transmission distance of it is 100m.