Synchronous Triggering Technology Study In Distributed Networked Test System

For the study of the regular of objects and changing processing, advanced test method is widely applied to measure, record, and conduct the follow up analysis and processing, all these need precise time synchronization.Utilizing the networked memory test of the distributed buoy for the transient state volume, measure dimension can be augmented, the space time overlay area can be expanded, the resolution ratio can be enhanced, and what's more it's more safe and reliable. However, this system must operate unified analysis and processing for the test outcome by the stations equipped with different kinds of sensors separated near by the object, therefore, coherence and precision of the timing system is highly required. While now the timing system equipment cannot be applied in testing system for its cost, volume, etc. So it's necessary to work on the study of the timing system in distributed memory testing. For the memory testing system, the gathering and storage memorizing of the tested parameter under the given condition is necessary, there is no need for the realization of real time synchronization among the stations but the marking and record for the occurrence moment of the key event.Follow up the thought and utilize the best current remote wireless time synchronous method—GPS which is based on the time synchronization requirement of studying the transient state volume testing system to provide the standard timing signal for the whole testing system, there are two time synchronization plans, plan A is a relative timing system, after abstracting the GPS time information, the testing and control main station sends the time service command to stations by radio. Plan B is a absolute timing system, every single buoy station directly receive the GPS time information, testing system is free to choose one of them according to the actual circumstance. In addition, introducing a circuit, a set of program, two mode, a kind of embedded multi-channel trigger signal record module is designed, which forms a synchronous trigger system with peripheral time service devices, which is able to precisely measure, mark and store the time difference between the timing impulse signal rising edge and event impulse signal rising edge, peripheral equipment can send operation command to the module by SPI interface or RS-485 interface for reading and resetting. This system can be installed on the testing station, and operating unmanned, further more, aim to the oscillation and impulsion of severe condition if any, redundancy designs which are expected to resolve the time synchronous problem among stations or stations and main station in distributed memory testing system have been down.The test outcome indicate that the finished designed synchronous triggering subsystem is not only processing high time synchronizing record precision and reliability, but also small in volume, low power consumption, low weight, flexible utilization, cheap, free to operation , all these can totally satisfy the operation requirement of memory testing system also it has a good fortune for practical popularization.