frame(DatFM)。DatFM can transmit measuring date。 ATC-FM send receiving response to sending side after receiving the data and feedback the current state information to check the correctness of transmit data。TTC-FM is used for approving the real-time trigger signal。 EtherCat transmission protocol principal takes the ethernet frame as the prototype, simplify the ethernet frame。Its function is roughly as same as the serial communication protocol,has two kinds of frames,included:PC—>counting card command frame(CmdFM) ,counting card—>PC response frame(ResFM)。In frame it has some information,such as address of corresponding equipment,length of data and so on。
This paper designs and completes hardware working block diagram of the project。It is based on the working principle of dual-frequency laser Interferometer and the functional requirements of main modules of hardware to make a rough flow block diagram of light path part and circuit part。
Keywords:Dual-Frequency Laser Interferometer;High-Speed transport protocol;functional requirements;HSSL optical Fiber transmission;EtherCat