When a telephone line cut is detected (which takes around a minute), a Phone Trouble alarm is activated.
By default, this gives a fast trouble beep for 10 seconds.
Although it is possible to program a full alarm to occur when there is a telephone line cut, it is not recommended because of the likelihood of false alarms due to interruption of telephone service If there is a Line cut at the same time as a power failure, the siren is activated immediately.
The UCM/GSM module is available for high security installations. This will use the GSM network as a backup when the phone line is unavailable for any reason