Abstract:

For TII(Transducer Independent Interface)protocol，there are different application methods and implementations，which need to be modeled，analyzed and verified．In this paper，first，according to diferent channel types，a hierarchical CPN(Colored Petri Net)model of TII protocol is established．Then，by using the average delay of data transmission，the channel utilization，the data transfer rate and the loss rate of data frames as performance evaluation indexes，the performances of the model are analyzed with the help of CPN Tools．Moreover，the performance indexes，which are affected by such interface parameters as interface rate，sampling rate ratio，sampling data length and buffer queue length，are discussed，and several methods and measures are proposed to improve model perform ances，such as increasing the channel data length and adopting controllable continuous sampling，virtual multi—channel，last—in—first·out buffer and first—in—first—out packet loss．Application results of the proposed model show that，when STIM channel is BDS(Buffered Data Sequence)，the lOSS rate of data frames，the data transfer rate and the average delay of data transmission are 0，1 500 B／s and 0．21 ms，respectively．

Key words: TII protocol, colored Petri net, IEEE 145 1, smart sensor