Bell output only activates for 30 seconds even though it is programmed for 99 minutes.
When the fire bell time (address 0195 in version 3, address 4032 in version 4) or burglary bell time (address 0196 in version 3, address 4033 in version 4) is set to 99 for a DS7400Xi version 3 or 4 this sets the bell cutoff time to 30 seconds.
For indefinite bell output then these programming addresses should be set to 00. For 98 minutes of bell output these should be set to 98.
Part numbers DS7400X, DS7400, DS7400Xi, DS7400XIVER2, DS7400XIVER3+, DS7400XIVER4+,