Digi One IAP not recieving data RS485 two wire half duplex 9600 bd no echo

i cannot seem to get a connection when using the DIGIone IAP. I can take the same two wires to a 485-usb convertor and read everything on modscan but when i hook those up to 3&4 or 6&7 or both 3 jumped to 6 and 4 jumped to 7 still no comms. all settings on serial port are the same as the modbus gateway i am trying to talk to. tried terminated and unterminated.
Any help is appreciated

Can you see your RS-485 traffic on the RS-485 to USB converter when you try to communicate? Do you have an oscilliscope to see what the difference is between 485 to USB and your device? What is your device? A modbus VFD?

Did you get this figured out? Or just give up on this forum where no one answers questions?