What does "Code Not on File" Mean?
Common digital alarm communicators send their signals to the Central Station using one of numerous predetermined "data formats."
Each particular data format has a certain number of digits or characters in its message. A typical alarm message in the very common "4/2" format would be something like this:
1234 11
"1234" is the account number that identifies your system.
"11" is the alarm code. It tells the Operator what kind of signal is being sent.
A few typical alarm codes might be:
11 Fire
44 Burglary
88 Low Battery
Every code which your system is meant to use needs to be listed at the Central Station. If an unlisted code is received, the computer returns a conversion of "No Code on File," or "NCOF" or "NCF."
Modern alarm control units are capable of sending such a variety of signals that some won't be needed by your application. For example, a "Sprinkler Supervisory Alarm" would be rare in a residential system. There is no point in listing such codes in your computer record, because they will just cause confusion and wasted effort. However, if your system has unused zones, they will often be programmed as burglary or fire zones, to accommodate possible expansion or rearrangement of your system. If those zones are later implemented, a NCF code could result if a signal comes in before the Dealer updates the Central Station records.
The response to a "No Code on File" signal will be whatever "default" response has been specified by the Alarm Dealer. In many cases, it could mean no response or a seriously delayed response.
You must depend on your Dealer to know what codes your system can send and to post an accurate code list into your Central Station records.
If an alarm panel or digital dialer has been replaced, it is imperative that the Central Station records be updated to reflect any new data format that has been used.