GRT Avionics Sport SX User manual

Sport SX
Installation Manual
Including Legacy Sport HS/WS Installation
Revision A
May 2019
GRT Avionics, Inc.
3133 Madison Avenue SE
Wyoming, MI 49548
616-245-7700
[e-mail]
grtavionics.com

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Sport SX Install. Manual I Rev. A
FOREWORD
Congratulations on your purchase of the GRT Avionics EFIS! We are pleased that you
have chosen our product to meet your flying needs!
This manual describes the installation of the GRT Sport SX and legacy Sport HS and
Sport WS display units using the software version shown in the Record of Revisions.
Some differences may be observed when comparing the information in this manual to
other software versions. Every effort has been made to ensure that the information in this
manual is accurate and complete. Visit the GRT website, www.grtavionics.com, for the
latest manuals, software updates and supplemental information concerning the operation
of this and other GRT products. GRT is not responsible for unintentional errors or
omissions in the manual or their consequences.
Information in the document is subject to change without notice. GRT Avionics, Inc.
reserves the right to change or improve their products and to make changes in the content
of this material without obligation to notify any person or organization of such changes or
improvements.
Copyright © 2001 - 2019 GRT Avionics, Inc. or its subsidiaries. All rights reserved.

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RECORD OF REVISIONS
Revision
Date
Sport
SW Revision
Description
A
May
2019
SX 15.00
and prior
Re-issue as a standalone manual for
Sport SX/Sport HS/Sport WS

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Contents
FOREWORD....................................................................................................................I
RECORD OF REVISIONS..............................................................................................II
SECTION 1: GENERAL DESCRIPTION.........................................................................1
1-1: Introduction...........................................................................................................1
1-2: Certification...........................................................................................................2
1-3: System Description and Architecture....................................................................2
1-4: Integrating Third-Party Equipment........................................................................3
1-5: Display Unit Features and Limitations..................................................................3
1-6: Supported Equipment...........................................................................................4
SECTION 2: PLANNING YOUR INSTALLATION ...........................................................6
2-1: Choosing Your Serial Port Assignments—the Key to a Good Installation!...........6
2-2: Common Equipment Interfaces............................................................................7
2-2-1: Other GRT Avionics Display Units—the Inter-Display Unit Link.....................7
2-2-2: Autopilots.......................................................................................................8
2-2-3: Autopilot Using GRT Avionics Servos............................................................8
2-2-4: Trio Avionics and TruTrack Flight Systems External Autopilots.....................8
2-2-5: ADS-B Receivers...........................................................................................9
2-2-6: ADS-B GPS Output .......................................................................................9
2-2-7: Remote Transponders...................................................................................9
2-2-8: Panel-Mounted Transponders .......................................................................9
2-2-9: Communication and Navigation Radio Tuning.............................................10
2-2-10: External GPS Sources...............................................................................10
2-2-11: IFR GPS Navigator Sources......................................................................10
2-2-12: GPS Data to External Devices...................................................................10
2-3: Gray Code Altitude Encoder Output...................................................................11
2-4: USB Port ............................................................................................................11
2-5: Audio Output.......................................................................................................11
2-6: Analog Inputs......................................................................................................11
2-7: Optional Features...............................................................................................11
2-8: Loss of GPS Data...............................................................................................11
2-9: For More Information..........................................................................................12
SECTION 3: PHYSICAL INSTALLATION.....................................................................13
3-1: Display Unit Installation......................................................................................13

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3-2: Remote Digital Magnetometer Installation..........................................................13
3-3: Legacy Analog Magnetometer Installation for Sport SX200...............................14
3-4: Cooling Considerations ......................................................................................15
3-5: Pitot-Static Connections.....................................................................................15
3-6: Angle-of-Attack Pressure Port Connection.........................................................16
SECTION 4: WIRING....................................................................................................17
4-1: General Guidelines.............................................................................................17
4-2: Power Connections ............................................................................................18
4-3: Ground Connections...........................................................................................18
4-4: Magnetometer Wiring.........................................................................................19
4-5: Specific Equipment Interconnect Details............................................................19
4-6: Warning Light Output..........................................................................................20
SECTION 5: INITIAL CHECKOUT, BASIC CONFIGURATION SETTINGS AND
CALIBRATION..............................................................................................................21
5-1: Display Unit Checkout........................................................................................21
5-2: Basic Configuration Settings ..............................................................................21
5-3: Configuring the Serial Ports................................................................................21
5-4: Required Setup for the Internal GPS..................................................................22
5-5: Internal GPS Settings.........................................................................................22
5-6: AHRS/Air Data Computer Test...........................................................................22
5-7: Setting AHRS Orientation...................................................................................23
5-8: Magnetometer Location Validation.....................................................................24
5-9: Analog Magnetometer Wiring Problems –Sport SX200 (Legacy WS and HS
Only)..........................................................................................................................25
5-10: Set Final Magnetometer and Instrument Orientation........................................25
5-11: Check the Uncorrected Magnetic Heading.......................................................26
5-12: Fine Magnetometer Calibration Procedure.......................................................26
5-13: Measuring the Accuracy of the Magnetic Heading ...........................................28
5-14: How Accurate Should the Magnetic Heading Be?............................................29
5-15: Other Required Settings and Options...............................................................29
APPENDIX....................................................................................................................31
A-1: 6.5” Sport SX Mounting Template ......................................................................32
A-2: 8.4” Sport SX Mounting Template ......................................................................33
A-3: Sport HS Mounting Template.............................................................................34
A-4: Sport WS Mounting Template............................................................................35

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A-5: External Module Diagrams.................................................................................36
A-6: Magnetometer Installation Diagram ...................................................................37
A-7: Sport SX Internal GPS Diagram.........................................................................38
A-8: Sport SX200A (Adaptive AHRS) Connector A Pinout Diagram..........................39
A-9: Legacy Model SX200 Connector A Pinout Diagram...........................................40
A-10: Magnetometer –Digital and Analog (Legacy)..................................................41
A-11: Sport SX200A Suggested Connector A Pinout Diagram (Dual-Screen System)
...................................................................................................................................42
A-12: Legacy Model SX200 Suggested Connector A Pinout Diagram (Dual-Screen
System) .....................................................................................................................43
A-13: Sport SX100 Suggested Connector A Pinout Diagram (Multi-Screen System) 44
A-14: Angle-of-Attack (AOA) Installation and Calibration...........................................45
A-14-1: Sensed AOA Installation............................................................................45
A-14-2: Calculated AOA Installation.......................................................................45
A-14-3: Calibration of the AOA (Calculated and Sensed) ......................................45
A-15: Sport SX Display Unit Specifications................................................................46
A-16: Table of Figures...............................................................................................47

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SECTION 1: GENERAL DESCRIPTION
1-1: Introduction
This document provides the physical, mechanical and electrical characteristics and
installation requirements for the GRT Sport SX Electronic Flight Instrumentation System
(EFIS). The information and processes in this manual are also applicable to the Legacy
Sport models HS and WS.
This manual is set up in order to match the steps you will follow to install this equipment.
•Description of the display unit –What the equipment does.
•Planning your Installation - What this equipment can do for you
•Physical installation –How to install it
•Wiring –How to wire it
•Initial Checkout, Basic Configuration, and Calibration –How to set it up and
check it out.
This manual, the Sport Setup Guide and the Sport User’s Guide comprise the entire
set of Sport user documentation.
*NOTE: This manual refers to the EFIS, display unit and screen; although it may seem
like these are all interchangeable terms, it is importantto note that theyall refer to different
aspects of the Sport SX stem:
•EFIS: Electronic Flight Instrumentation System. This refers to the Sport SX system
as a whole; it includes the display unit, peripheral devices and the components
that connect them together (such as wiring harnesses). Alternatively referred to as
“the system.”
•Display Unit: This is the centerpiece of the EFIS. It is made up of the electronic
components that connect to the peripheral devices and the physical elements that
the pilot uses to interact with the system. It takes the data from the peripheral
devices, processes it and then displays a human-readable version of that data on
its screen for the pilot to use. Abbreviated and referred to as “DU;” may also be
referred to by model name, “Sport SX.”
•Screen: This is the physical screen of the Display Unit; it’s what all the data from
the system is displayed on for the pilot’s use.

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1-2: Certification
The GRT Sport EFIS is not certified for installation in FAA Type Certificated Aircraft. It is
designed and intended for installation in VFR aircraft licensed as Experimental or Light-
Sport.
1-3: System Description and Architecture
The GRT Sport SX EFIS consists of a panel-mounted Display Unit and a remotely-
mounted magnetometer. The Sport SX is available in two configurations: one for use as
a Primary Flight Display (PFD)and one as aMultifunction Display (MFD). The two models
are designated as S200 (PFD) and S100 (MFD).
The display unit provides a graphical display of primary flight data, moving map/HSI and
engine data. The display of engine data requires the EFIS to be connected to a GRT
Engine Information System (EIS) Engine Monitor. Dimensional drawings for the Sport SX,
Sport HS and Sport WS display units along with the magnetometer are provided in the
Appendix sections A-1: 6.5” Sport SX Mounting Template, A-2: 8.4” Sport SX
Mounting Template, A-3: Sport HS Mounting Template, A-4: Sport WS Mounting
Template and A-5: External Module Diagrams.
The GRT Sport EFIS may be operated as a single or multiple screen system. Within each
display unit is a processor, power supply and screen that allow it to process and display
information independent of another EFIS display unit (except for unique data that may be
coming from other display units). This allows multiple screens to provide redundancy.
Multiple screens are normally linked together via a serial inter-display link to share pilot
entries, such as baroset, dimming, flight plan, etc…
Interfacing to other systems is accomplished via serial ports, and in some cases, the USB
port. The Sport SX is also connected to the aircraft pitot/static system for sensing
airspeed, altitude and vertical speed. The internal AHRS provides roll and pitch attitude
data. When a magnetic heading is provided via the remote magnetometer, the gyro
heading data is also provided. Without the magnetic heading data from the
magnetometer, gyro-stabilized GPS ground track is provided. The GRT AHRS is unique
in the industry in that it can provide attitude data without external aiding from air data or
GPS.
The Sport SX EFIS display units have two model numbers. The S200 is used as the
primary flight display (PFD) in a multi-display system, or the only display in a single-
display system. It contains the AHRS, Air Data Computer and altitude encoder for the
transponder. It may also contain the optional Internal GPS, but this is typically installed in
the secondary unit in multi-unit systems.
The S100 is used as a multifunction display (MFD) or slave unit. It’s never used as the
primary unit. It does not contain an AHRS, air data computer or encoder, but may contain
the Internal GPS, if optionally ordered. The S100 may be used to display map and

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weather data or engine instrumentation. It may also be used as a redundant display of
the flight instrumentation through the inter-display link. If a builder prefers dual AHRS
systems for redundancy, a second S200 should be used in place of the S100.
An internal GPS is standard in the Sport SX S200. Any external GPS may also be used,
as long as its serial data output is in one of the commonly used avionic formats. Most
GPS units will always transmit their flight plan, allowing the EFIS to display either the
GPS’s flight plan or its own internal plan. This ability is useful for adding IFR GPS
capability to the Sport system via an IFR-approved GPS navigator. Please note that only
the GPS functions will be transmitted via a GPS serial output, such as position, ground
track, groundspeed, flight plan, etc…Other data provided to an external GPS (such as
weather) are not displayed on the GRT EFIS screen (unless this data is also available to
the EFIS, such as weather from an ADS-B receiver). Database information (such as
airport frequencies, runway information, etc…) will always come from the EFIS navigation
database.
When the GRT Avionics Engine Information System (EIS) unit is connected to the EFIS,
its data is displayed on the EFIS screen. The EFIS enhances the usefulness of the engine
data by adding such features as an EGT time history, percent power and engine efficiency
(specific fuel consumption). The EIS may include its own digital display or may be fully
remote. The ENG page on the EFIS is dedicated to engine and environmental
parameters. Engine data can also be displayed on a portion of the primary flight display
page.
1-4: Integrating Third-Party Equipment
GRT Avionics differentiates itself from other manufacturers by embracing compatibility
with third-party equipment. This allows new technologies to be adopted quickly and gives
the owner the ability to take full advantage of the advances made in a competitive
marketplace. This includes equipment like Comm/Nav radios, transponders, ADS-B
transponders/receivers and many other devices. The addition of a second or third display
unit doubles or triples the number of available serial and USB ports, allowing for the use
of more third-party devices. The inter-display link between display units also allows for
data from most devices to be shared amongst the units for redundancy and convenience.
See section 2.2 - Common Equipment Interfaces, the Appendix, or the GRT Avionics
website (www.grtavionics.com/home/compatible-equipment/) for more information on the
various GRT system & third-party equipment configurations.
1-5: Display Unit Features and Limitations
A partial list of features and limitation includes:
•Complete Primary Flight/Map/Engine display functionality (optional sensors
required).

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•Optional Synthetic Vision with 10-mile range; displays terrain, obstacles, airports
and more.
•Sunlight-readable LCD displays; dimmable to less than 5 nits for night flying.
•Internal AHRS/Air Data computer; provides critical attitude, altitude and airspeed
data.
•Supports internal GRT GPS, external GRT GPS Safe-Fly module and third-party
GPS.
•High-Integrity AHRS; does not require pitot-static or GPS aiding.
•Internal, world-wide database.
•Receives deviation data from Nav radios (excludingthose with composite outputs).
•ADS-B transponder/receiver support; display of weather and traffic.
•Displays Traffic Information Service (TIS) traffic (when used with Mode S
transponder).
•Interfaces with Garmin SL30/40 to display VOR/ILS/GS and tune preset radio
frequencies.
•Fully-integrated autopilot functionality for GRT and third-party units.
•Flight director.
•Customizable split-screen views, PFD-MFD screen swap, Engine Page and
Moving Map overlays.
•Up to 5 serial ports (4-port version standard; 5-port version available with the
upgraded processor option).
•Optional ARINC 429 expansion module; allows full integration with Garmin panel-
mounted GPS.
1-6: Supported Equipment
The list of serial-port compatible equipment includes:
•ADS-B (Traffic and Weather)
•GRT EIS Engine Monitor (All Versions)
•GRT Autopilot Servos
•External Autopilots (Trio Avionics and TruTrack Flight Systems)

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•Single or Dual GPS Receivers (All Types)
•Full Nav Interface with Garmin:
oGNC Series Nav/Comm (420/420W)
oGNS Series GPS/Comm (480) and GPS/Nav/Comm
(430/430W/530/530W)
oGTN Series GPS/MFD (625/725), GPS/Comm/MFD (635) and
GPS/Nav/Comm/MFD (650/750)
•Single or Dual Interface with Garmin SL30/SL40
•XM Satellite Weather
•Guardian Avionics CO Guardian Series CO Detector
•TIS Traffic Datalink (GTX 330)
•Zaon Flight Systems PCAS XRX and MRX
•BF Goodrich WX-500 Stormscope
•Vertical Power VP-X Series Electronic Circuit Breaker System
•Serial Data Input Transponders
•TCAS (Traffic Collision Avoidance System/Traffic Alert and Collision Avoidance
System)

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SECTION 2: PLANNING YOUR INSTALLATION
Modern flight instrumentation systems may seem intimidating, but they can be easier to
install than their analog counterparts. This section provides some basic information for
aircraft builders new to the world of electronic flight display systems.
2-1: Choosing Your Serial Port Assignments—the Key to a
Good Installation!
A key element to designing a glass-panel installation is the communication between
different components of the system, which occurs primarily through the serial port
connections. For systems with multiple display units, it is essential to consider the effect
of any single device failure—a power bus, GPS unit, etc… Although less likely to occur,
it is also important to consider the effects of multiple device failures on the system. These
considerations are pivotal to any airplane that’s operated in instrument conditions.
Multiple device failures are unlikely; however, they can occur in conditions that effect
multiple elements of the plane’s avionics. Such conditions include static discharge (not a
consideration in aluminum airplanes, but essential to consider with fiberglass airplanes),
water leaking into the airplane (when entering the plane during rain, any opening in the
canopy during flight, especially the vents), an over-voltage condition that can occur if the
battery becomes disconnected, loss of charging, etc…
Electrical connections to the EFIS display unit are made through the D-sub connectors
affixed to it and its accompanying wiring harnesses. The connectors are pre-wired for
required, dedicated functions, such as power, ground and warning light output
connections. Up to five of the terminal positions in the connectors (four standard with an
optional fifth) are reserved for use as serial ports.
All serial ports are user-configurable, allowing them to be used with a wide variety of other
equipment. Each serial port consists of two contacts–a Transmit (OUT) and a Receive
(IN)–that exchange information between the display unit and a connected device, such
as a GPS, radio or autopilot. Some devices will only transmit data (such as a GPS), while
some will only receive data (such as altitude data to a transponder). Some devices
transmit and receive data, such as autopilot servos.
A stream of serial data is like a sentence, with data packets being the words of that
sentence. Data packets are transmitted in a predetermined order and frequency. This
frequency is known as the baud rate. A device that communicates at a baud rate of 9600
delivers 9,600 coded data packets per second in a sequence that the receiving device
expects. The baud rate of a serial port in the display unit must be configured to match
that of the device connected to it. Note: that when two devices share one serial port, they
must use the same baud rate.
Some limitations that should be considered when planning your serial port
connections:

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•The baud rate set for the serial port in the EFIS corresponds to BOTH the serial
input and output.
•The type of function for an EFIS serial input does not have to match; the baud rate,
however, MUST match. For example, Serial Input 1 on the EFIS could be wired to
an EIS engine monitor. It is configured for 9600 baud. Serial Output 1 on the EFIS
could then be used to send altitude data to a transponder, if it accepted data at
9600 baud.
•The hardware designof the serial inputs tothe EFIS can’t exceed RS-232 standard
loads; this ensures that any standard RS-232 output can provide data to multiple
EFIS display units with no loss of fidelity. For example, since serial output from an
external GPS can be wired to multiple GRT EFIS display units, its signal can be
corrupted if the loading from the EFIS exceeds the standard.
•The Sport SX serial ports are all high-speed, meaning that any serial port can be
used with any device, regardless of the baud rate the connection may require. The
Legacy Sport WS and HS models have a single high-speed port (serial port 4),
which is typically used to provide ADS-B weather or XM weather to the EFIS.
2-2: Common Equipment Interfaces
This section is an overview of the typical interconnectionsthat are made to other avionics.
It is intended to inform you of the benefits of connecting your GRT EFIS to other
equipment. Refer to the latest revisions of the Equipment Supplements for each third-
party component for the most detailed and up-to-date wiring and setup information
(www.grtavionics.com/home/compatible-equipment/).
2-2-1: Other GRT Avionics Display Units—the Inter-Display Unit Link
This connection allows two or more display units to function as one integrated system, so
pilot inputs do not need to be duplicated on each display unit. The following pilot entries
are always shared over the inter-display unit link:
•Baroset
•Display Dimming Level
•Flight Plan
•Limits (compared between display units at power-up)
•Autopilot/Flight Director Mode and Targets
•EFIS Navigation Mode

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The inter-display unit link can also share specified data that only a single display unit may
be receiving, including any analog inputs.
2-2-2: Autopilots
An autopilot provides the greatest benefit for the cost of almost any addition to the
airplane. It is an essential tool for single pilot IFR and highly beneficial for any VFR pilot
that undertakes cross-country flights. The autopilot frees up the pilot to perform other vital
tasks, such as looking for traffic, radio tuning, evaluating imminent weather, etc…We
highly recommend it for all airplanes, with the exception of those that are not flown cross-
country. If you have chosen not to install an autopilot, but may do so in the future, we
recommend installing the servo wiring at the very least, and possibly installing the servo
mounting kits as well. This will make the addition of the servo easier in the future. This
also increases the value of the airplane for any future owner if it is sold without an autopilot
installed.
2-2-3: Autopilot Using GRT Avionics Servos
An autopilot using GRT Servos provides excellent performance and is the easiest
configuration to implement. The installation will require wiring for the servos, mounting
kits to attach the servos to your airplane, a power-switch for the servos and an
engage/disengage button. A single serial port is used to control both the roll and pitch
servos.
When using multiple GRT EFIS display units, any display unit can function as the autopilot
mode controller. Adding an autopilot switch to a second display unit ensures functionality
in the event that the primary autopilot-controlling display unit fails.
2-2-4: Trio Avionics and TruTrack Flight Systems External Autopilots
Most of our customers use GRT Servos for their autopilot needs. However, airplanes with
existing autopilots can still interface with any GRT EFIS. This is accomplished via a serial
output from the EFIS for lateral-only steering. Autopilots that provide vertical steering
require an ARINC 429 adapter to receive GPSS and GPSV commands, which requires
the use of both a serial input and an output from the EFIS.
External autopilots that include their own source of gyro data provide some degree of
redundancy with the AHRS data from the EFIS when the autopilot is coupled. This benefit
is offset by slight transients in pitch when the autopilot is initially coupled to the EFIS. It
also requires more button presses than when GRT servos are used. Since GRT servos
can be mounted in place of TruTrak or Dynon servos, many of our customers choose to
sell their autopilot and install GRT servos; in this instance, the existing mounting kits and
wiring can be used. The required changes to the electrical connections for this switchover
are not difficult to make.

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2-2-5: ADS-B Receivers
All ADS-B receivers that provide data in the standard ADS-B format can be wired to the
display unit for weather and traffic data. Most ADS-B receivers provide data in this
standard format, except for some Garmin units. We find the inclusion of ADS-B weather
and traffic to be very beneficial and highly recommend its integration into your airplane’s
avionics systems. ADS-B receivers can be purchased for as little as a few hundred
dollars.
2-2-6: ADS-B GPS Output
The GPS output from the Sport SX’s internal GPS is NOT FAA 2020 compliant for use
with ADS-B or mode S with extended squitter transponders. If this GPS position data is
used, the FAA will detect that a noncompliant GPS is being used. However, the GRT
Safe-Fly GPS is 2020 ADS-B compliant and is approved by the FAA for this use. This
GPS also includes a serial combiner that provides the EFIS with 3 more serial ports.
Additionally, this GPS provides accuracy and integrity data that is used by the Sport SX.
The integrity validation performed by this GPS is similar to that performed by IFR-certified
GPS navigators.
2-2-7: Remote Transponders
The Sport SX supports fully remote transponders, including the Trig TT22 and Uavionix.
These have several advantages over traditional panel mounted transponders:
•No panel space is required.
•The EFIS interface is easy to use.
•More flexibility in the mounting location.
•The EFIS can have automated control over the transponder.
•Multiple display units provide multiple ways to control the transponder.
A serial input and output is required to interface a display unit with a Uavionix remote
transponder. If the Trig TT22 is being used, an RS-422 interface (or a serial input and
output with a Trig Adapter) is needed to connect it to the display unit. When the remote
transponder and display unit are interfaced, the connection provides altitude data and
control of the transponder to the display unit.
2-2-8: Panel-Mounted Transponders
The EFIS provides altitude encoding information to all common transponders. Gray code
outputs are provided for older transponders that do not have a serial input for altitude

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data. The Sport SX requires an external adapter for Gray code altitude encoding outputs.
Newer transponders may allow either serial output or Grey code.
2-2-9: Communication and Navigation Radio Tuning
The EFIS has the ability to load the Garmin SL30 and SL40 radios with frequency pre-
sets, allowing convenient selection of these frequencies from the front panel controls of
the radio. For the SL30, the EFIS can also tune the navigation radio. This data is
transmitted to the radio via an RS-232 serial output from the EFIS display unit.
Display of Navigation Data from the SL30: The EFIS provides an HIS and other functions
that display and use the VOR bearing data provided by the SL30 Nav/Com. Localizer and
glide slope deviation data is also displayed on the EFIS from this radio. This data is
transmitted to the radio via an RS-232 output from the EFIS display unit.
Multi-Display Unit Considerations: Although the navigation data from the SL30 is
communicated to other display units via the inter-display unit link, it is preferable to
connect the serial data output from the SL30 to two display units independently. This
allows the SL30 navigation data to be displayed in the event that one of the display units
fails. One serial data output from the SL30 may be connected to multiple display units.
Only one serial data output TO the SL30/SL40 is provided, but in this case, redundancy
is not an issue. If the display unit that provides the tuning data to the SL30/SL40 is non-
operational, the radio would simply be tuned with its front panel controls.
2-2-10: External GPS Sources
Practically all external GPS receivers provide a serial output that is compatible with the
input formats accepted by the EFIS display unit. Position, groundspeed, ground track and
the flight plan are normally provided by the GPS. The display unit supports two GPS
inputs. The GPS source used bythe EFIS is selected on the display unit Navigation Mode
softkey.
2-2-11: IFR GPS Navigator Sources
The Sport SX is fully-compatible with IFR GPS navigators from Garmin and Avidyne. The
optional ARINC 429 Interface is required to receive VOR/ILS information from these
devices, as well as to provide them with EFIS data that the GPS can use for enhanced
functionality. A serial connection is enough to receive the GPS position, groundspeed,
track and flight plan data.
2-2-12: GPS Data to External Devices
Configuring any serial output to “Autopilot-NMEA 0183” will provide NMEA0183 GPS
position, speed and ground track data; the flight plan is not transmitted.

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2-3: Gray Code Altitude Encoder Output
Older transponders use an interface called Gray Code to receive data from altitude
encoders. Since the Sport SX does not contain an internal altitude encoder, an external
adapter is used for interfacing with this type of transponder. All newer transponders have
the option to use serial data instead of Gray Code, so use of this adapter is not common.
2-4: USB Port
In some cases, other equipment may communicate with the display unit via a USB
connection. A USB port is easy to connect and transmits large amounts of data quickly.
USB devices do not require you to program a baud rate. The Sport SX has one USB port
that may be used for one USB device. Alternatively, you may attach a USB hub to connect
up to three devices. Software updates are also delivered to the EFIS via USB—simply
install the software update files onto a USB thumb drive from the GRT website, then
connect the thumb drive to the EFIS USB port. The EFIS will upload the files as per the
Update instructions found in the Sport Setup Guide.
2-5: Audio Output
The Sport SX feature an audiooutput; it provides amethod of alertingthe pilot when limits
are exceeded, altitude call-outs on approach, traffic alerts and much more. The audio
output is wired through the intercom or audio panel.
2-6: Analog Inputs
The Sport SX does not include analog inputs, however, the EIS engine monitor provides
up to six auxiliary inputs that can be used for trim and flap position.
2-7: Optional Features
The Sport SX includes a moving map, ADS-B displays, Bluetooth wireless compatibility,
five serial ports and audio alerting as standard features. Synthetic Vision/Terrain relief
map and angle-of-attack are available options. Touchscreen, basic engine monitoring and
analog inputs are not available at this time.
2-8: Loss of GPS Data
While it is expected that the EFIS will be provided with GPS data for accurate navigation
information, it is a possibility that all GPS data could be lost. If this occurs while in flight,
the EFIS will dead-reckon from its last known GPS position. Due to varying winds and
sensor errors, the EFIS system position will degrade in accuracy over time. The intent of
the dead-reckoned system position is to provide approximate position information so that

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the pilot has time to implement other means of navigation, such as visual observations,
VOR, etc…
2-9: For More Information
Depending on what your “mission” is, you may want a simple VFR system, or an IFR
system with many built-in redundancies. The GRT system enables customization for the
entire range of possible configurations, from simple to sophisticated, depending on the
builder’s desire and skill level.
While this manual covers the very basics of EFIS wiring and communication, along
with GRT Sport-specific details, there are many very important safety aspects of
aircraft wiring that we cannot even begin to discuss in this manual. The techs at
GRT recommend the following sources for more information on proper aircraft
avionics & electrical system design:
•The “Aeroelectric Connection” by Bob Nuckolls is a great place to start. It covers
everything from the very basics of electricity to the proper design and installation
of sophisticated IFR-capable systems.
•EAA columnist Tony Bingelis’s books have long been a staple of experimental
aircraft builder knowledge. In addition to wiring considerations, Mr. Bingelis
discusses all aspects of kitplane building, from spinner to tail. The books are: The
Sportplane Builder: Aircraft Construction Methods, Sportplane Construction
Techniques: A Builder’s Handbook, Firewall Forward: Engine Installation
Methods and Tony Bingelis on Engines.
•FAA Advisory Circular 43.13-2B provides the “certified” reference for safe and
durable aircraft wiring techniques, though it is a bit outdated. It is available online
as a free download from www.faa.gov.
•The Experimental Aircraft Association has compiled a collection of videos called
“Hints for Homebuilders”on its website, www.eaa.org. A quick search through
these will give you valuable hints on various wiring topics, including properly
crimping D-sub/Molex connector pins.

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SECTION 3: PHYSICAL INSTALLATION
3-1: Display Unit Installation
Mount the display unit(s) in the desired location in the instrument panel. The main
consideration in choosing a location is the ability to view the display unit and reach its
controls. Since the screen is fully sunlight-readable, no consideration for shielding the
display unit from sunlight is required. Be mindful of the space behind the instrument panel
as well; some aircraft with tip-up canopies, for example, have canopy supports that may
interfere with the back of the EFIS when the canopyis closed. See the Appendix sections
A-1: 6.5” Sport SX Mounting Template, A-2: 8.4” Sport SX Mounting Template, A-3:
Sport HS Mounting Template and A-4: Sport WS Mounting Template for display unit
dimensions and clearance requirements for the rear of the unit.
1. For panel-mount style display units, the use of nut plates behind the instrument
panel greatly simplify the task of installingand removing the 4 screws used to retain
the display unit in the panel. #6 socket cap stainless steel screws are
recommended.
2. For radio rack style display units, the #6 screws on the side of the unit (2 per side)
should be used to attach the display unit to the radio rack.
3-2: Remote Digital Magnetometer Installation
The remote magnetometer must be placed in an area of the airplane with little or no
electromagnetic interference. The cable is 20 feet long and designed to reach out to the
wingtip or tail. The magnetometer is marked with an arrow pointing in the direction of
flight. Mount it with the arrow pointing forward, parallel to the centerline of the airplane.
There is not a designated “top” of the magnetometer, so it can be turned on its side for
easier mounting. The side of a wing tip rib is a simple place to put it. The arrow on the
magnetometer should be parallel with the centerline of the airplane for yaw. Pitch attitude
is not critical as long as it is within 60 degrees nose up or nose down.
60° up limit
Longitudinal Axis
60° down limit
Figure 3-1: Magnetometer Pitch Range

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*NOTE: The most common cause of magnetic sensing error is simply magnetic
disturbances near the magnetometer. This can be caused by ferrous metal (any metal
that a magnet will stick to), control cables or cable carrying electrical currents, such as
navigation or landing lights, being too close to the magnetometer. The magnetometer’s
location will be tested for interference in Section 5: Initial Checkout, Basic
Configuration Settings and Calibration, after the initial boot-up checks of the Sport SX.
3-3: Legacy Analog Magnetometer Installation for Sport
SX200
Determining the location of the magnetometer requires considerable care because of the
magnetometer's sensitivity to magnetic disturbances generated by the airplane. No
periodic maintenance is required for the magnetometer, although it is desirable to mount
it in a location that allows access to it if necessary. The most important consideration
when mounting the magnetometer is choosing a location in the airplane that is away from
magnetic disturbances. It is quite amazing how sensitive the magnetometer is to these
disturbances and how much error this can cause in the magnetic heading reported by the
AHRS.
Keep the magnetometer at least 12 inches away from any current carrying wires (such as
navigation or landing light wires) and more than 18 inches from ferrous metal, such as
the steel mass balance tube that is typically used in the leading edge of ailerons. Use
non-ferrous hardware (or even double-sided sticky tape) for mounting the magnetometer.
You can test your proposed magnetometer location prior to mounting the magnetometer
itself by placing an ordinary compass at the spot. Then:
1. Turn on and off any electrical equipment whose wiring passes within 2 feet of the
proposed magnetometer location.
2. Move the flight controls from limit to limit.
3. If the proposed magnetometer location is within 2 feet of retractable landing gear,
operate the landing gear.
Observe the compass while doing each of the above processes. The goal is for there to
be no movement from the compass needle, although movement of less than five degrees
is acceptable. If you observe the needle moving greater than five degrees at any time, try
another location. After the installation and wiring of the magnetometer and display unit(s)
is complete, a more sensitive check for magnetic disturbances will be conducted.
The magnetometer and the AHRS in the Primary Flight Display unit work together. For
this reason, they must be oriented in the same direction; that is, the pitch, roll and yaw
axes of the magnetometer and the PFD display unit containing the AHRS need to be
parallel. A standard level can be used to orient the magnetometer and display unit such
that they are equal in roll and pitch. For yaw, the orientation of these devices should be