I just inherited this building with a small system 600 panel. Its primarly used for start-stop and some elementary control functions. The owner wants to keep it because its currently working. There is no front end or software on-site. There is a modem and controllers (part# 545-700LT and 545-703. The controllers are gray so I think they are MBC's (modular building controllers). The owner would like access just to make schedule changes. I think that can be done using hyperterminal through the RJ-11 port to a DB9 serial port on a PC. Does anyone have the wiring info. for that cable or is there another way ?

Thanks