Hi, sorry I'm unable to help you with this question, but I have a question for you since I have the same model;IMA 4006 series, which is quite outdated so I'm unable to locate a users manual for it. But the question is, how to I set up the master control unit so that I can communicate with all the rooms with an intercom installed. I can't seem to figure out the configuration for the switches on the panel to get it working!!! Your help will be appreciated, and I hope you find an answer to your question too!!! Thanks Calvin