The Design And Completion Of Founctional Test System For STM16(SFP) Port Board

Firstly, this paper introduces SDH theory, especially the definition of the frame structure and overload, this is also theoretic preparation for our explanation of test technology of STM-16 boards.After the detailed introduce of SDH theory, in order to complete the functional test of 2.5G STM-16(SFP) port in SDH Add/Drop Multiplexer (1660SM R5.0 Equipment), we will analyse the test theory of it from every aspect.Referring to ITU-G.783 recommendation, STM-16(SFP) port board performs the Transport Terminal Function on a STM-16 data stream. It also performs the High Order Path Layer Trail Termination and the High Order Path Layer Adapation functions on 16 STM-1 equivalent signals.The STM-16 signal received from the line is exchanged three times with two MATRIX boards(1+1 configration) for cross connection ( HPC & LPC) processing: regenerator and multiplex section transport overhead insertion/extraction;high order path overhead insertion /extraction; payload assembly/disassembly at VC4 level and at lower order VCs level; DCC access; Loopback testing capability. Next,we develop a set of test platform (including Hardware environment and Software part) based on the STM16 test theory. We wish we can coding with VISUAL BASIC,utilize GPIB card/cables to remote control every instruments, just like SDH Analyzer (ANT20); Optical power and Optical attenuator(OMS-150); Oscilloscope (TEK CSA8200); Splitter, then, to complete the functional test of STM-16 narrowband port(SFP), including Voltage, program download, Optical power, Sensitivity, BER, Jitter etc.The main problems are focus on making optical switch control board, control of the instruments, the definition of every test item.Optical switch control board can properly control the optical switches; the control of the instruments including the settingup of the GPIB address,initialization, preparation before testing; the definition of every test item is base on the setting of every kinds of instruments and send commands by the serial port and parallel port in order to read the measurement data, and then decide if it is pass or not after comparing the values.At last, copleting the debugging of the optical switch control board when it is made. Control all the instruments with coding and create a test system based on a shelf.