Electronic Alarms and Home Security Devices - Caretaker Plus

I have a Caretaker Plus Alarm system. It was installed about 15 years ago and we have NEVER had any problems with it. I am very happy with it. I understand that they are no longer in business.
I recently had Cox Communications (we have used their phone service for over 2 years and the alarm worked fine)out to repair static on our phone line. The alarm system was disabled while the phone work was being done. The static was eliminated (Cox guy said there were a bunch of wires bunched together in the basement and he "unbunched" them)and the phone was turned back on. Ever since the Cox guy left, however, I have been unable to arm or disarm my alarm system from a house phone-wired or wireless. I am able to perform all fuctions using the alarm keypad.
The alarm monitoring company does not know what to do and the Cox people don't either. The Cox guy just left after conferring with the alarm support and nobody knows how to correct this. They are all scratching their heads and other parts of their anatomy.
Anyone have any ideas? Do I need wiring schematics? Any old installation books out there?

Check to see if you have a dialtone at the phone jack for the panel (Unplug the alarm line, and plug in a regular phone). If not, in the midst of his fix, the Cox tech probably disconnected the alarm from the phone line.

Possibly, he may have altered it's position in the phone lines. For this thing to work correctly, it has to be first in line from the dialtone source/telco incoming line. (see the link for wiring a RJ-31x jack in the FAQ for this forum)

Thank you so much for your help. The cable people left a few hours ago and I now have phone access to my alarm system. Your information was extremely helpful.