|+20||0||Set alarm (local time)|
|1||Set alarm (UTC)|
|+24||Depends on reason code at +20|
This message can be sent used to set/cancel alarms.
If the message is recorded, then the application
!Alarm acknowledges with 0 if successful or a null terminated error string. (Presumably this is in the error block at +20, but unsure. If it is, then the message block format is inconsistent, depending on whether it is to or from the application).
When setting an alarm using local time, it is possible to add out-of-range alarms to the database, which
!Alarm will fault on redraw (but not fault on save).
When the task goes off
!Alarm broadcasts Message_AlarmGoneOff, which your application should acknowledge.