StageAge54 Posted June 8, 2022 Report Share Posted June 8, 2022 Hello friends.I am using a PLC communicating with an UAC CB 01RS4. What I want to achieve is an meter MODBUS measuring the volt and amp value of a load, connected to a PLC via Modbus, this PLC is connected to a computer via ethernet.I managed to establish communication but didn't suceed. Indeed, All attempted sessions are fails and the status is 3 - Connection exists, but there is an error in the MODBUS commands. I have added the MODBUS module to the PLC on UniLogic, and all informations (Modbus panel, baud rate, data bit....) are correct. Then I've added a Master -> 'registers periodic' -> the modbus communication is the UAC-CB-RS4 and the adress is 5000 (which is the adress register of the Voltage measurement content (for the automate). I also tried to add a slave but still I have the same errors. If you have any clue on why I have a connection but the MODBUS command has errors, please tell me 😀. Thank you very much !! Quote Link to comment Share on other sites More sharing options...
Gabriel Franco Posted June 8, 2022 Report Share Posted June 8, 2022 I suggest to double check wiring, network configuration (ID, baud and so on) on the meter side and register numbering, response timeout. Also, first try using a Modbus software. Any chance that 5000 is hex? If so, set decimal address. Quote Link to comment Share on other sites More sharing options...
MVP 2022 kratmel Posted June 8, 2022 MVP 2022 Report Share Posted June 8, 2022 Please post meter model name plate or pdf manual. Some models have non modbus protocol on board. Quote Link to comment Share on other sites More sharing options...
MVP 2022 Ausman Posted June 8, 2022 MVP 2022 Report Share Posted June 8, 2022 Gabriel and Kratmel, does Unistream stuff also do the register number offset of 1 that Vision does? Perhaps this is the issue? And Stage, trial your comms using a PC first, then once proven transfer the known good parameters to the PLC's commands. Quote Link to comment Share on other sites More sharing options...
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