Installation Manual For DigiFlight Series Autopilots TRUTRAK FLIGHT SYSTEMS 1500 S. Old Missouri Road Springdale, AR 72764 Ph: 479-751-0250 Fax: 479-751-3397 www.trutrakflightsystems.com info@trutrakflightsystems.
INSTALLATION MANUAL for DigiFlight Series Autopilots TABLE OF CONTENTS Mechanical Considerations ........................................................................ 1 Pitot / Static Connections ........................................................................... 2 Magnetic Considerations............................................................................ 2 RFI / EMI Considerations .......................................................................... 2 Electrical Wiring ............
Mechanical Considerations The installation information in this section is extremely important and must be clearly understood by the installer. Improper servo installation or failure to observe and diagnose installation problems prior to flight can result in extremely serious consequences, including loss of ability to control the aircraft. If there are any questions on the part of the installer it is mandatory to resolve these questions prior to flight of the aircraft.
Pitot and Static Connections ( DigiFlight 200 / 200 VS Only ) All multi-servo TruTrak autopilots require connections to the pitot and static lines. The preferred method of this connection would be tee fittings near the aircraft’s altimeter. The static line for the autopilot requires due care in its construction, as excessive lag or insufficient static orifices can cause the autopilot to oscillate (hunt) in pitch.
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 Autopilot Rear Connector Wiring (continued) P101 Pin 32 33 34 35 36 37 Function Notes Roll (aileron) Servo control lines. These lines cause the stepping motor in the roll 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 roll servo as shown on wiring diagram.
Specific connections for certain commonly-used in-panel GPS units Note that the information in the tables is based upon the best information available from each manufacturer’s documentation at the time of publication. Please consult the appropriate installation manual for confirmation of wiring information.
Note that for the GX-50/60/65 units, the autopilot will need to be set for 9600 baud. The autopilot’s ARINC-A and ARINC-B inputs should be left unconnected, as steering information in the case of UPSAT units is sent over the serial RS232 line along with the ground track and ground speed information the autopilot needs. The serial GPS Steering information is only recognized by DigiFlight units which contain the GPSS Option.
DigiFlight 100 Initial Checkout Once wiring is completed the autopilot should be tested in the aircraft while on the ground. The first step is to enter the setup mode on the autopilot and set all parameters to their correct values. Apply power to the autopilot programmer. The initial screen should be displayed, along with the words PWR UP in the lower-right of the display. After approximately ten seconds, the autopilot is ready to be set up for operation, indicating AP OFF on the display.
The next step in the check-out procedure is to verify that the serial input from the GPS receiver is being properly received and interpreted. With the aircraft outside of any building, power up the GPS panel-mount receiver and the autopilot. After the GPS receiver acquires its position, the autopilot will begin to flash the “*” character once per message from the GPS unit showing that valid position data is available.
DigiFlight 200 / DigiFlight 200 VS Initial Checkout Once wiring is completed the autopilot should be tested in the aircraft while on the ground. The first step is to enter the setup mode on the autopilot and set all parameters to their correct values. Apply power to the autopilot programmer. The initial screen should be displayed, along with the words PWR UP in the lower-right of the display.
The next step in the check-out procedure is to verify that the servos run, and in the correct direction. At this point, the display differs depending on autopilot model. DigiFlight 200 The screen will show that the altitude portion of the autopilot is still disengaged. Press ENTER to engage the altitude hold function. DigiFlight 200 VS The lower-right of the screen will show the present value of selected vertical speed, (SVS) which will be approximately zero.
control system lockup at the extremes of servo travel. Insure that any “lost motion” in the linkages is eliminated or minimized, in order to maximize the performance of the autopilot. Lost motion (dead zone) will result in wandering or slow “hunting” behavior in flight. The next step in the check-out procedure is to verify that the serial input from the GPS receiver is being properly received and interpreted. With the aircraft outside of any building, power up the GPS panel-mount receiver and the autopilot.
The reason for setting LAT TORQUE to a setting less than its maximum (250) is to reduce the current draw of the servo and to make it easier to override the autopilot should the need arise. Manual override is not normally required, as using the controlwheel switch or holding the knob for three seconds, then releasing it, will disengage the autopilot, but it is best to have a setting of torque which can be comfortably overridden if necessary.
Magnetic Calibration The DigiFlight autopilot contains a built-in magnetometer which is used to maintain gyro centering and slaving for the built-in Electronic DG of the autopilot in case of GPS loss. This magnetometer is icalibrated at the factory in a disturbance-free environment, but once installed in the aircraft it may be necessary to account for any magnetic disturbances in the aircraft itself.
INSTALLATION NOTES: 1. USE #20 AWG FOR POWER AND GROUND WIRES TO SERVO (PINS 1 AND 9 ON 9-PIN CONNECTOR J201) AND WIRE TO AUTOPILOT MASTER AND SINGLE-POINT GROUND. ALL OTHER WIRING #20 TO #24 AWG. 2. INSTRUMENT LAMP DIMMER CONTROL IS OPTIONAL. 12V SYSTEMS: CONNECT J101 PIN 4 TO DIMMER CONTROL AND J101 PIN 18 TO GROUND. 28V SYSTEMS: CONNECT J101 PIN 18 TO DIMMER CONTROL ( J101 PIN 4 NO CONNECT ). 3.
INSTALLATION NOTES: 1. USE #20 AWG FOR POWER AND GROUND WIRES TO SERVOS (PINS 1 AND 9 ON 9-PIN CONNECTORS J201 AND J301) AND WIRE TO AUTOPILOT MASTER AND SINGLE-POINT GROUND. ALL OTHER WIRING #20 TO #24 AWG. 4. PITCH SERVO ONLY: REVERSAL OF SERVO DIRECTION CAN BE ACCOMPLISHED AS NECESSARY BY INSTALLING OR REMOVING A JUMPER BETWEEN PINS 1 AND 2 OF THE 37-PIN CONNECTOR ( CUSTOMER'S J101 MATING PROGRAMMER P101 ). 2. INSTRUMENT LAMP DIMMER CONTROL IS OPTIONAL.
TRUTRAK FLIGHT SYSTEMS 1500 S. Old Missouri Road Springdale, AR 72764 Ph: 479-751-0250 Fax: 479-751-3397 www.trutrakflightsystems.com info@trutrakflightsystems.
