I recently had to implement alternate floor fire service on a 1230mp. If you look at the print for the fire service you will see the main fire service smoke contact as normally opened between FE (H1) and 48F (H2). Closing the contact recalls elevator to the main fire floor. However, if you look at the alternate floor circuit, you will see 2 normally open contacts, one to close between LFE, and ICOM, and the other to close between the main input FE, and 48F. It seems that both contacts are to close at the same time for alternate fire service. I had trouble with this setup, sometimes the car will recall to alternate and sometimes to main. The only way I could get alternate floor to work right everytime, was to close LFE to ICOM first, and then close FE to 48F. I couldn't find any literature about this circuit in any of the old 1230 manuals I have. I do know that the above sequence will work every time.