I am using a AB7702 as an interface from a Modbus TCP/IP Master (PC) to a Modem Modbus RS485 acting as a slave.
We can communicate with the Modem from a PC Serial Modbus Modbus using Calta MDBus (see below), but we had to increase RTS/TX Delay to 1, and RTS Extra to 10 to connect to the Modem.
I have tried all possibilities of timer settings within the AB7702 serial settings, also reversing the two RS485 wires, but no success with communicating to the Modem via the AB7702. I believe the issue maybe related to RTS/CTS.
Do you have any suggestions what I could try to solve this issue?