ORSO2001 Posted February 24, 2018 Report Share Posted February 24, 2018 Dear Alls, I have to set up my Unistream to works at same time as Slave by Modbus RTU TCP and Masert by Modbus RTU RS485. I already wrote the program part about slave (Modbus TCP) than I set PLC communications->Protocols->MODBUS->Slave->Panel Ethernet...I have set the registers and "wrote" the code...now I am approcing the Slave side...my question is: I must use/set the same PLC communications->Protocols->MODBUS->Master->RS485 or I can mix/use the first with the PLC communications->Physical->Serial COM ? I hope that my qestion is clear enough. thanks Link to comment Share on other sites More sharing options...
ORSO2001 Posted February 25, 2018 Author Report Share Posted February 25, 2018 ok...I found what I have to do....and also reading again my first post this has no sense...sorry usually I used unitronics as master using the "advanced modbus"...now I am trying to use "periodic/aperiodic" and at this point I have few questions: - using "advanced modbus" if a data exchange don't works I use an instruction to empty the buffer to try again...using "periodic/aperiodic" this works automatically or I have to do something? - when I compile the project I have a warning like: Do NOT place "COM: MODBUS" Ladder elements on the bus bar, or anywhere it will be continuously activated. Use a delay of 10-50 msec between requests. Click on "Find All Elements" to locate all of the instances where it is used in the program ...I placed a "P" contact and a "modbus aperiodic trigger" to do some test...this warning is for safety or I am missing something? thanks Link to comment Share on other sites More sharing options...
sgull Posted February 27, 2018 Report Share Posted February 27, 2018 I also have that error- Do NOT place "COM: MODBUS" Ladder elements on the bus bar, or anywhere it will be continuously activated. Use a delay of 10-50 msec between requests. Click on "Find All Elements" to locate all of the instances where it is used in the program Also the command is not being called continuously (with a positive transition contact). The program appears to work OK,but I still get this error at each download. Any help would be appreciated Link to comment Share on other sites More sharing options...
Saragani Posted February 28, 2018 Report Share Posted February 28, 2018 It is just a warning, ignore it. We cannot detect (unless the element is directory on bus bar) that it will be called continuously or not), since it might be on a bus bar of another function that is called through a timer, or the other way around: not on bus bar, but after a Contact that is always open dues to the state of the connected bit. Link to comment Share on other sites More sharing options...
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