The Tecmar internal modem (d9350/9351) served as a security dongle to enable you to use RAM or RPS software for communication. When that device stops working and you remove it from the computer, or you upgrade to a computer you can’t install it in, you will have to get an external security dongle.
There are two different part numbers for the external security dongle.
D5370-LPT runs off the LPT port
D5370-USB runs off the USB port
After installing one of the external security dongles you will be able to resume communications with the alarm system panels