I was a programmer for the video surveillance company that was in turn Kalatel, Interlogix, and GE Security. It is now owned by United Technologies and using the Interlogix name.
I wrote the built-in software for PTZ cameras, interface units and control equipment. My main focus was the KTD-405 keypad and controller. I wrote most of the original code, added a number of features later and maintained the code (bug fixes etc.) for the 5 years that I was with the company. I have been retired for several years, but still may be able to answer questions about the KTD-405.