Unacknowledged Emergency Alarm

As of R2.8.0, it is possible for a radio to transmit an emergency alarm a fixed number of times, without being acknowledged, before it proceeds with the emergency call.  Preamble can also be prefixed to these emergency alarm transmissions.

Normally, the only way a radio could transmit an emergency to a group of radios was to have a dedicated always-on radio generate the required acknowledgement. Also, because of this, it was also not possible for radios to receive the emergency alarm while scanning.

Now, with this feature available and turned on, the transmitting radio will ignore any acknowledge received and continue to retry transmissions until the configured number of retries (both Impolite and Polite) have been exhausted. Enabling this ensures that any scanning radios will also receive the emergency call.