
GRT Avionics, Inc.
May 2019
Sport EX/Horizon EX Install. Manual
18
Rev. A
4-3: Ground Connections
The cable assembly provided includes 22 gauge wire for the ground return of the display
units. This will result in a voltage drop of about 0.015V/ft, which is acceptable for wire
lengths of up to
5’.
4-4: Digital Magnetometer Wiring
Typically, the magnetometer harness supplied with the EFIS will not have its D-sub
terminals plugged into the connector housing. This makes it easier to route the cable
through the airplane. After the cable has been routed, the wires can be cut to length if
desired (new terminals will have to be crimped on the wire ends). If the wires are not cut,
inspect the D-sub connector terminals to verify that they have not been damaged. Insert
the designated wire into the appropriate D-sub connector housing position according to
section
A-6: Digital Magnetometer Pinout Diagram
. If desired, the crimp-type D-sub
connector can be replaced with a solder-type connector.
All magnetometer connections are made directly to the mating display unit with internal
AHRS. This wiring includes the power connections necessary for the magnetometer to
operate.
The digital magnetometer serial output may be shared between any number display units
with Adaptive AHRS or stand-alone Adaptive AHRS.
4-5: Specific Equipment Interconnect Details
Most equipment shares information with the display unit via a serial port connection. Each
serial port in the DU that is wired to another device must be configured so that the DU
knows what it has been connected to. This is accomplished via the “Set Menu,” within the
“General Setup” menu. Each serial port is listed and entries are provided that allow them
to be configured for a wide variety of functions. Since all serial ports on the Sport EX are
high-speed, they are capable of receiving data at 115,200 baud and can be used for any
function.
Detailed instructions and wiring information for connecting to specific other avionics
equipment, along with EFIS pinout information, are provided in the
Appendix
, as well as
being
provided
as
Equipment
Supplements
on
GRT’s
website
www.grtavionics.com/home/compatible-equipment/
).
Depending on the other equipment installed in the airplane, switches may be necessary
or desirable for some functions. For example, a switch to allow the autopilot to be
controlled by the EFIS, or directly from the GPS, allows the GPS to control the autopilot
in the event that the autopilot-controlling display unit fails.