Research And Implementation Of Interchangeable Engine About Universal Test Instrument On IVI-C

IVI driver divides the instrument driver into two layers with the hierarchical designpattern. It includes class driver and specific driver. The class driver explicitly calls thespecific driver by parsing configuration file, establishes mapping relationships betweenthe two drivers, and completes control of the instrument. When changing instrument,the user only need modify the corresponding information in the configuration fileswithout modifying the test program to achieve the interchangeability of the instrument.The emergence of IVI driver development technology realizes the instrumentinterchangeability of the same type. It improves the reusability of the test procedure,promotes the development of instrument driver technology. It also provides a keytechnology for the development of automatic testing system.Based on IVI driver model, the interchangeable engine of universal test instrumentwas designed and implemented according to the IVI standards by using the C API. Themain research contents include:(1)Designing the configuration store interface and parsing the configuration storefile. Based on the object-oriented idea, different objects were managed by differentclasses. Using Python language and GTK libraries completed the design ofconfiguration store interface. The users can use configuration store to completemanagement of the driver information, meanwhile generate the correspondingconfiguration files. The analytical principle of the configuration server and Expatanalytic package were analyzed. The parsing of the XML files were designed andimplemented both on the Windows platform and Linux platform.(2)The design and implementation of attribute management mechanism. Theattributes were divided into two categories which were channel attribute andnon-channel attribute. Use the dynamic link list to store the attribute with the blockmanagement thought. The attributes which are in the same data type were stored in thesame link list. Different function interface were designed according to the date type ofattributes. The attribute were managed separately to finish the operation of reading,writing and adding to the attribute. (3)The design and implementation of channel management mechanism. Instrumentrepeated capabilities were researched. The applications of the virtual and physicalidentifiers were discussed. Virtual identifier was managed by class driver and physicalidentifier by specific driver. Finally, it achieved dynamic management, scalability andlow coupling.(4)The design and implementation of IVI class driver. The class driver of arbitrarywaveform generator was designed and implemented based on the research ofdevelopment process and design requirements. It included driver structure,implementation of function module and the program package both on the Windows andLinux platforms. Finally it achieved cross-platform.It is proved by the test that the instrument interchangeability was realized. And theinterchangeable engine can realize cross-platform, multi-language, and meets the designrequirements.