When executing a command, the keyfob's LED blinks
red once to indicate transmission of the command to
the control panel. If the operation is successfully
completed, the green LED lights momentarily and a
"Success tune" is heard. If the operation fails or
cannot be completed, for example, when the system
is "not ready", the red LED lights steadily and a
"Failure tune" is heard
,
see KF-234 PG2 User's
Guide, “Panel Response to Keyfob Commands”
section 3.2.