Hello Geo1,
Could you please elaborate whether you currently have a ModemCOM with TM11q, or an FM tracker?
TRM250 is more like ModemCOM rather than FM tracker. All communication with TRM250 modem is via terminal only (i.e. putty.exe), and only via AT commands. There is no software for TRM250 configuration.
So depending on what you want to accomplish, TRM250 may or may not be suitable.
Hope this helps