Garmin GPS 24XD NMEA 2000 User manual

GPS 24XD NMEA 2000®
INSTALLATION INSTRUCTIONS
Important Safety Information
CAUTION
To avoid possible personal injury, always wear safety goggles, ear protection, and a dust mask when drilling,
cutting, or sanding.
NOTICE
When drilling or cutting, always check what is on the opposite side of the surface to avoid damaging the vessel.
For the best performance and to avoid damage to your boat, read all installation instructions before
proceeding. Install the device per these instructions. Use the appropriate fasteners, tools, and mounts listed,
which are available at most marine dealers.
The Garmin® GPS 24xd NMEA 2000 high-sensitivity GPS antenna provides position information to your existing
NMEA 2000 network. If your boat does not have a NMEA 2000 network, you will need to install one.
For more information, go to garmin.com.
Tools Needed
• Drill
• 3.2 mm (1/8 in.) drill bit
• 19 mm (3/4 in.) drill bit for a pole-mount cable-hole
• 25 mm (1 in.) hole saw for a surface-mount cable-hole
• Countersink bit for mounting on fiberglass
• Screws for under-deck mounting
• Screwdriver, appropriate for the screw type
• Marine sealant (optional)
• Additional NMEA 2000 network components as needed
TA-2020/6796
GUID-28CE8C25-CFD8-4C12-B6D0-AD9CDF4D5084 v3June 2021

Mounting the Antenna
Antenna Mounting Considerations
CAUTION
Do not install or store the antenna near strong magnets, including speakers. A strong magnetic field can
damage the antenna.
You can mount the antenna on a flat surface or attach it to a standard 1 in. OD, 14 threads per inch, pipe-
threaded pole (not included). You can route the cable outside of the pole or through the pole. For best
performance, consider these guidelines when selecting the antenna mounting location.
• To ensure the best reception, the antenna should be mounted in a location that has a clear, unobstructed
view of the sky in all directions .
• The antenna should not be mounted where it is shaded by the superstructure of the boat , a radome
antenna, or the mast.
• The antenna should not be mounted near the engine or other sources of Electromagnetic Interference (EMI)
.
• The antenna should not be mounted near known ferrous metal objects such as a toolbox or compass.
• A handheld compass should be used to test for magnetic interference in the area where the antenna is to be
mounted. Your boat, motors, and devices must be on during the test.
If the needle on the handheld compass moves when you hold it where you intend to mount the antenna,
magnetic interference is present. You must choose another location and test again.
• Mounting screws are provided with the antenna. If you use mounting hardware other than the provided
screws, the hardware must be made of quality stainless steel or brass material to avoid magnetic
interference with the antenna.
NOTE: Test all mounting hardware with a handheld compass to make sure no magnetic fields are present in
the hardware.
• If a radar is present, the antenna should be mounted above the path of the radar . If necessary, the
antenna may be mounted below the path of the radar .
• The antenna should not be mounted directly in the path of the radar .
• The antenna should not be mounted within 1 m (3 ft.) of a VHF radio antenna or the path of a radar .
2

Testing the Mounting Location
1Temporarily secure the antenna in the preferred mounting location and test it for correct operation.
2If you experience interference with other electronics, move the antenna to a different location, and test it
again.
3Repeat steps 1–2 until you observe full or acceptable signal strength.
4Permanently mount the antenna.
3

Surface Mounting the Antenna
NOTICE
If you are mounting the bracket on fiberglass with screws, it is recommended to use a countersink bit to drill a
clearance counterbore through only the top gel-coat layer. This will help to avoid cracking in the gel-coat layer
when the screws are tightened.
Before you permanently mount the antenna, you must test the mounting location for correct operation (Testing
the Mounting Location, page 3).
1Using the surface-mount bracket as your mounting template, mark the three pilot-hole locations and
trace the cable-hole in the center of the bracket.
2Set the surface-mount bracket aside.
Do not drill through the bracket.
3Drill the three 3.2 mm (1/8 in.) pilot holes.
4Drill the 25 mm (1 in.) cable hole in the center.
5Use the included M4 screws to secure the surface-mount bracket to the mounting surface.
6Route the cable through the center hole, and connect it to the antenna.
7Verify the large gasket is in place on the bottom of the antenna, place the antenna on the surface-mount
bracket, and twist it clockwise to lock it in place.
8Secure the antenna to the mounting bracket with the included M3 screw .
9Route the cable away from sources of electronic interference.
4

Mounting the Antenna on a Pole
Mounting the Antenna with the Cable Routed Outside the Pole
Before you permanently mount the antenna, you must test the mounting location for correct operation (Testing
the Mounting Location, page 3).
1Route the cable through the pole-mount adapter , and place the cable in the vertical slot along the
base of the pole-mount adapter.
2Screw the pole-mount adapter onto a standard 1 in. OD, 14 threads per inch, pipe-threaded pole (not
included).
Do not overtighten the adapter on the pole.
3Connect the cable to the antenna.
4Place the antenna on the pole-mount adapter and twist it clockwise to lock it in place.
5Secure the antenna to the adapter with the included M3 set screw .
6With the antenna installed on the pole mount, fill the remaining gap in the vertical cable slot with a marine
sealant (optional).
7Attach the pole to the boat if it is not already attached.
8Route the cable away from sources of electronic interference.
5

Mounting the Antenna with the Cable Routed Through the Pole
Before you permanently mount the antenna, you must test the mounting location for correct operation (Testing
the Mounting Location, page 3).
1Position a standard 1 in. OD, 14 threads per inch, pipe-threaded pole (not included) in the selected location,
and mark the approximate center of the pole.
2Drill a hole using a 19 mm (3/4 in.) drill bit for the cable to pass through.
3Fasten the pole to the boat.
4Thread the pole-mount adapter onto the pole.
Do not overtighten the adapter.
5Route the cable through the pole and connect it to the antenna.
6Place the antenna on the pole-mount adapter and twist it clockwise to lock it in place.
7Secure the antenna to the adapter with the included M3 set screw .
8With the antenna installed on the pole mount, fill the vertical cable slot with a marine sealant (optional).
9Route the cable away from sources of electronic interference.
6

Mounting the Antenna Under a Surface
NOTICE
Verify that the supplied screws will not penetrate the surface before you install the under-deck mounting
bracket. If the supplied screws are too long, use surface-appropriate screws instead.
Because the antenna cannot acquire signals through metal, it must be mounted under a fiberglass surface only.
1Determine and test the location under a fiberglass surface where you want to mount the antenna (Testing
the Mounting Location, page 3).
2Place the adhesive pads on the under-deck mounting bracket .
3Place the antenna in the under-deck mounting bracket.
4Adhere the under-deck mounting bracket to the mounting surface.
5Secure the under-deck mounting bracket to the mounting surface with screws.
6Connect the cable to the antenna .
7Route the cable away from sources of electronic interference.
7

Connecting the Antenna
NMEA 2000 Network Connection
If you do not have an existing NMEA 2000 network, you must install a NMEA 2000 network on your boat. For
more information on NMEA 2000, go to garmin.com/manuals/nmea_2000.
The antenna is packaged with a NMEA 2000 T-connector and a NMEA 2000 drop cable. You will use these two
components to connect the antenna to your existing NMEA 2000 network.
A 6 m (20 ft.) drop cable is included. If more cable is needed, add an extension to your NMEA 2000 backbone,
based on the NMEA 2000 guidelines. A shorter drop cable can be installed if desired.
GPS 24xd antenna
NMEA 2000 drop cable
NMEA 2000 T-connector
NMEA 2000 backbone
Heading Calibration
After installation is complete, you must calibrate the heading and perform the auto heading alignment to
receive magnetic heading data.
Depending on the types of devices connected to the NMEA 2000 network, you can calibrate the antenna using
either a menu-based method or a basic method.
If you connect the antenna to a NMEA 2000 network with a compatible Garmin chartplotter, you can perform
either the basic calibration or the menu-based calibration (Performing Menu-Based Calibration, page 9).
If you connect the antenna to a NMEA 2000 network without a compatible Garmin chartplotter or with a third-
party device, you must perform basic calibration instead of menu-based calibration.
8

Performing Menu-Based Calibration
Before you can perform menu-based calibration, you must connect the antenna to the same NMEA 2000
network as a compatible Garmin chartplotter.
1Select Menu > Settings > Communications > NMEA 2000 Setup > Device List.
2Select the GPS 24xd NMEA 2000 from the device list.
3Select Review > Compass Cal. > Begin.
4Follow the on-screen instructions until the compass calibration is complete, taking care to keep the boat as
steady and level as possible.
The boat should not list during calibration.
When the compass calibration is complete, a value appears near the Compass Cal. setting. A value near 100
indicates the antenna was installed in a perfect magnetic environment and calibrated correctly. If the
heading performance is unacceptable, and the value is closer to 0 than it is to 100, you might need to
relocate the antenna and calibrate the compass again.
NOTE: The antenna compass must be calibrated successfully and maintain a valid GPS position, which
requires the antenna to have a clear, unobstructed view of the sky in all directions, before you proceed to
Auto Heading Alignment.
5Select Auto Heading Alignment.
6Select Begin.
7Follow the on-screen instructions until the magnetic heading alignment is complete.
Disabling the Magnetic Heading Data
If you cannot mount the antenna in an ideal location for magnetic heading and GPS performance, you can
disable the magnetic heading data.
Perform a factory reset (Antenna Configuration, page 11).
The device still outputs GPS Course over Ground.
Adjusting the Fine Heading Alignment
You can adjust the Fine Heading Alignment in conjunction with Auto Heading Alignment to fine-tune the
heading output (optional).
NOTE: Fine heading alignment must be completed under open skies to ensure proper calibration.
1Select Settings > Communications > NMEA 2000 Setup > Device List.
2Select the GPS 24xd device.
3Select Review > Fine Heading Alignment.
4Using a landmark or a known good compass, determine the heading of your boat.
5Adjust the heading until it matches your measurement.
6Select Done.
9

Performing Basic Calibration
If you connect the antenna to a NMEA 2000 network without a compatible Garmin chartplotter or with a third-
party device, you must perform basic calibration instead of menu-based calibration.
Before you can perform basic calibration, you must be able to view heading data from the NMEA 2000 network
on a connected device. To perform basic calibration, you must remove from the network all sources of heading
data other than the antenna.
When performing basic calibration, you first calibrate the compass and then align the heading in one
continuous procedure.
NOTE: The boat must be able to reach a cruising speed of at least 6.4 km/h (4 mph) to perform the heading
alignment.
1Drive the boat to a location with calm, open water.
2Set the display to view heading data from the connected antenna.
NOTE: You must not use GPS Course Over Ground (COG) to perform basic calibration.
3Disconnect the antenna from the NMEA 2000 network or turn off the power to the NMEA 2000 network.
4Wait while the boat becomes level and stationary.
5Turn on power to the antenna, and wait until the heading data appears on the display .
NOTE: If you are performing the first basic calibration after a factory reset, the heading is blank.
6Within three minutes, complete two full, slow, tight circles , taking care to keep the boat as steady and
level as possible.
The boat should not list during calibration.
When the antenna is prepared to calibrate the compass, the heading data disappears from the display .
You may receive an error message that the heading was lost. You can ignore this message.
7Continue turning in the same direction at the same speed for approximately 1 1/2 rotations until the
heading data appears .
10