The DTH is the one i suggest. ULM is deprecated, it was replaced by Lock Manager.
For a comprehensive keypad solution, with entry and exit delays, user pin control, and panic key/pin support, I recently released SHM Delay version 2 Scroll down on that link, there is a section on Xfinity/Iris/Centralite Keypad Installation and TroubleShooting with links on how to reset and rejoin your keypad.