TruTrak Digiflight Install Manual - Manual (Page 5)

TruTrak Flight Systems DigiFlight Autopilot Installation Manual
3 March 2002 Printing
Electrical Wiring
All TruTrak DigiFlight series (DigiFlight 100, DigiFlight-200, and DigiFlight-200VS) autopilots have consistent wiring
requirements. Therefore, this manual covers all such units, with special notations covering any differences between the units.
The DigiFlight-200 programmer is mechanically identical to the DigiFlight-200VS and differs only in its internal circuitry and
software. The table below provides a brief explanation of each pin function on the main 37-pin connector P101.
P101
Pin
Function Notes
1 Dedicated ground connection for Pitch Reverse Jumper.
Pitch Reverse Jumper,
present or absent, as follows: Direction of servo arm / capstan rotation
(as viewed from face of the servo body)
for UP elevator
Pin 2 open (no connect): Servo CCW (counter-clockwise) ! UP
2
Pin 2 Jumpered to pin 1: Servo CW (clockwise) ! UP
DigiFlight 200 / 200VS
Only.
See note 4 on wiring
diagram
3 Auxiliary RS-232 Output. Presently unused, intended for future expansion.
4 LAMP1 (see also pin 18) A source of variable DC from external dimming source. Drives the
LCD backlighting circuit. If left disconnected, backlight will be full-on.
Dimmer is wired based on
supply voltage. See note 2
on wiring diagram
5, 6, 7
8,9
Reserved. Do not connect to these pins.
10 Pitch Servo Torque Control. A signal from the autopilot to the pitch servo which sets the
amount of torque to be delivered by the servo.
DigiFlight 200 / 200VS
Only.
11 Pitch Servo Trim Sensor. A signal from the pitch servo to the autopilot which indicates an
out-of-trim condition and its direction.
DigiFlight 200VS Only.
12 Autopilot Master (+12 to +28 V DC). The autopilot itself draws less than 0.5 ampere. Most of
the current required by the autopilot system is used by the servos (up to 1A per servo).
13 Reserved. Do not connect to this pin.
14
15
16
17 Pitch Servo control lines. These lines cause the stepping motor in the pitch servo to run in the
appropriate direction at the desired velocity. They are small-signal lines and do not have any
substantial current-carrying capability or require any special shielding. Connect to pitch servo
as shown on wiring diagram. DigiFlight 200 / 200VS
Only. Do not attempt to
reverse servo direction by
swapping wires
18 LAMP2 (see explanation for pin 4, above).
19 Ground Connection. Provide #20 AWG to common grounding point.
20 Control Wheel Switch. Connect as shown in wiring diagram to a SPST momentary switch
located remotely to the autopilot for convenient engage/disengage function.
21 22,
23, 24 Reserved. Do not connect to these pins.
25 Primary Serial Input. Baud rate selectable 1200,2400,4800 or 9600 baud. Automatically
decodes NMEA-0183, Garmin Aviation Format, or Apollo/UPSAT Moving-Map or GPSS
format. Provides directional reference to the autopilot.
26 ARINC-A
27 ARINC-B Digital differential signals from Garmin, Sierra, or other panel-mount receiver
which provide directional steering commands (GPSS) to autopilot GPSS Option Only
28 Roll Servo Torque Control. A signal from the autopilot to the roll (aileron) servo which sets
the amount of torque to be delivered by the servo.
GPSS Option Only
29 Reserved. Do not connect to this pin.
30 Auxiliary RS-232 Input. Presently unused, intended for future expansion.
31 No Connection. Reserved for future expansion.
Rear 37-Pin Connector P101
viewed from rear of unit
1
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19