I'd have to take a look at an Apex manual, since it's been a while for me, however first:
It would be benefitial to know what format the system was communicating in prior, without that, it'll be setting up the report codes and enabling reporting for functions. From memory, the Apex unit has quite a few fields that need to be set up for CID communication, as well as matching the CS template.
CID is universal in what it transmits, however getting a non "Ademco" control to transmit the information as intended is another affair
4 digit CID means to me that the account is 4 digits long, CID format, however your mileage may vary.