Address definition for master-slave communication between TRICON and PKS via MODBUS
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Our factory has a project that uses MODBUS communication between TRICON and PKS, with PKS acting as the master station to read from and write to TRICON. TRICON has defined an AI, alias 33001, which is a 32-bit memory-based real number. There is also an AO, alias 41001, which is a 32-bit memory-based real number as well. Reading is performed via MODBUS on the PKS side; points are created in QUICK BUILDER on the PKS side, and the PV SOURCE ADDRESS for AI is SIS_AI 05002 IEEEFPLB. The PV SOURCE ADDRESS for AO point is SIS_AO 05002 IEEEFPLB. SIS_AI and SIS_AO are controllers established on the PKS side; the code IEEEFPLB uses a little-endian format with byte swapping. I would like to know why both of the point addresses transmitted over the communication are 05002. How did 33001 and 41001 turn into 05002? Why are the two addresses the same?
This is related to the data structure and communication mechanism of Tricon. 33001 is just an alias for the variable, not its communication address. The corresponding actual communication address is 35001+35002 41001. Can you read from and write to it on-site normally? Refer to the documentation; your setting is incorrect. It should be 2002 IEEEFPLB
Thank you, you’re absolutely right. The program on the PKS side was developed by the manufacturer, and they got all the AO point addresses wrong. Since we haven’t used AO until now, we didn’t notice it; we only realized it while reviewing the program recently :)
“33001 is just an alias for the variable, not its communication address. The corresponding actual mailing address is 35001+35002. How is this mailing address converted? Please ask the experts for guidance