Motorola PR1500 - Manual (Page 37)

PR1500 27
Common Radio Features
Emergency Keep-Alive
With Emergency Keep-Alive enabled, if the radio is in the Emergency
state, you cannot turn off the radio by using the On/Off Volume
Control knob.
With Keep-Alive, the radio will only exit the Emergency state using
one of the ways mentioned in the previous sections (Emergency
Alarm, Silent Emergency Alarm, or Emergency Call).