Honeywell PRIMUS 1000 Pilot's Manual page 222

PRIMUSr1000 Integrated Avionics System
The ASEL mode automatically arms when the aircraft climbs or
descends towards the alert altitude and the following conditions are
met:
ASEL altitude is more than 250 feet from the current altitude
D
Computed vertical speed is greater that actual vertical speed
D
Vertical speed is greater than 100 fpm for 3 seconds
D
Glideslope is not captured.
D
The ASEL mode is cancelled in altitude hold, or at glideslope capture.
When the altitude select capture detector trips, the ASEL mode is
captured and the other active vertical mode is dropped. The PFD
displays ASEL in green.
At ASEL capture, a command is generated to flare the aircraft onto the
selected altitude.
The aircraft remains in the ASEL capture modes until the following
conditions exist simultaneously:
Altitude error less that 25 feet
D
Altitude rate less than 5 feet/second.
D
When these three conditions exist simultaneously, the system
automatically switches to altitude (ALT) hold.
NOTE: Changing the selected altitude on the GC while in the capture
phase, cancels the active ASEL mode and the armed ASEL
annunciation is displayed.
Table 8--10 is an illustrated step through of the ASEL procedure. The
numbers in figure 8--24 correspond to the procedural step numbers in
table 8--10. Figures associated with each step number show the PFD
annunciations after the step has been completed.
Modes of Operation
8-34
A28--1146--112--00