Problem with modbus


Thread Starter


I'm trying to communicate a PLC TSX3722 sv 5.0 with a TSX Nano using Modbus, but the following error is detected: "Exchange stopped on time-out".
Why is this error present? How can I resolve it?

thank you.


You have forgotten to write what channel is used by the TSX3722 (PCMCIA card TSXSCP114 or terminal port with a CPU SV>=V5.0). Probably the TSX Nano (slave) doesn't answer to the request of the TSX3722 (Master). There are a lot of reasons.... one basic being the wiring, the others the transmission format, the last the kind of request and its coding.

Give me more information by e-mail please. About the wiring, there is a possibility of mistake between the marking on the nano(A,B,SG) and the marking of the TSX3722 (D(A)/D(B)/D-/D+). A must be wired to D(B) and B to D(A) in our case. Don't forget the link between the OV. Please send me an E-mail with more information.
thank you very much for your reply. the problem was in wiring and the solution was to permute D(A)& D(B)in nano PLC.