Cirrus SR22 Pilot Operating Handbook page 366

Section 9 Cirrus Design
Supplements SR22 / SR22T
Flight Management System Keyboard
The Flight Management System Keyboard, found in the center
console below the AFCS mode controller, is the primary means for
data entry for the MFD and is used to control NAV/COM Radios,
transponder, and flight management system entry. Heading, course
and altitude select are also provided.
28 VDC for Flight Management System Keyboard operation is
supplied through the 5-amp KEYPADS / AP CTRL circuit breaker on
MAIN BUS 1.
AFCS related functions are as follows:
HDG - Heading Knob.
The HDG knob controls the selected heading bug on the HSI portion
of the PFD. It provides the reference for heading select mode. Pushing
the HDG knob synchronizes the selected heading to the current
heading.
CRS - Course Knob
The CRS knob controls the course pointer on the HSI portion of the
PFD. It provides the reference for FD navigation modes when the
Flight Director is selected. Pushing the CRS knob re-centers the CDI
and returns the course pointer to the bearing of the active waypoint or
navigation station.
ALT SEL - Altitude Select Knob
The ALT knob controls the Selected Altitude, which is used as the
reference for the altitude alerter and the altitude capture function.
Pushing the ALT SEL knob synchronizes the selected altitude to the
displayed altitude to the nearest 10 ft.
18 of 32 P/N 13772-135
Revision 04: 09-08-14