Are any other non default settings required?

The Modem works fine on the Serial Port of the PC.
But on the TS Serial ports it doesn’t work. I use the original Digi cable For the TS–>Modem connection:
RJ45(10pin)/DB25 Straight (part# 76000198).
I see that the program is trying to talk to modem (the lights on the modem blink) but says that settings on the modem are wrong
(again as I said everything is fine if I use the same modem on the PC Com Port).
All the settings for the serial port on TS are default.
So, is it anything I need to do with the Serial Port settings on TS?

Does any of the information in either of these KB articles help?