Garmin GPS 18 5Hz Manual

The Garmin GPS 18 5Hz is a high-performance, 5Hz update rate GPS sensor designed for precision applications. It features WAAS/EGNOS capability, NMEA 0183 and RS-232 output, rugged waterproof construction, and low power consumption. Ideal for marine, automotive, and aviation use where fast position updates are critical. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: GPS 18 5Hz sensor, Power/data cable, Mounting hardware, Waterproof housing.

Feature	Description
Update Rate	5Hz (5 updates per second)
Accuracy	Typically <3 meters with WAAS/EGNOS enabled
Output Protocols	NMEA 0183 v3.01, RS-232
Power Input	6-40 VDC, reverse polarity protected
Connector	6-pin sealed circular connector
Operating Temperature	-30°C to +80°C
Waterproof Rating	IPX7 (submersible to 1 meter for 30 minutes)
Antenna Type	Internal patch antenna with external connector for optional external antenna
LED Indicator	Power and satellite lock status
Dimensions	72mm x 46mm x 25mm

Installation

Unpack and inspect contents. Select mounting location with clear view of sky.

1. Mount the unit: Use provided bracket and hardware. Ensure mounting surface is clean and dry.
2. Connect power and data: Route cable to power source and host device (PC, chartplotter, etc.).
3. Connect optional external antenna: If required, attach to SMA connector on unit.
4. Apply power: Connect to 6-40 VDC source. Green LED will illuminate.

WARNING! Ensure power is off during installation. Do not mount near strong RF sources or obstructions.

First-Time Setup

Power on GPS 18; allow time for initial satellite acquisition.

1. Initial acquisition: May take up to 5 minutes for first fix under open sky.
2. Verify operation: Check LED (solid green = tracking satellites; blinking = searching).
3. Configure host device: Set serial port to match GPS output (default: 4800 baud, NMEA).
4. Enable WAAS/EGNOS: For improved accuracy, ensure WAAS/EGNOS is enabled in supported regions.

CAUTION! Do not expose to temperatures beyond specified range during operation.

Specifications

• Receiver: 12-channel GPS with WAAS/EGNOS.
• Update Rate: 5Hz (user configurable to 1Hz).
• Position Accuracy: <10 meters (GPS), <3 meters (WAAS/EGNOS).
• Velocity Accuracy: 0.1 knot RMS steady state.
• Time Accuracy: 1 microsecond synchronized to GPS time.
• Data Output: NMEA 0183 v3.01 (GGA, GLL, GSA, GSV, RMC, VTG, ZDA).
• Serial Data Format: 8 data bits, no parity, 1 stop bit.
• Baud Rate: 4800 (default), configurable to 9600, 19200, 38400.
• Power Consumption: 140mA @ 12VDC typical.
• Weight: 85 grams.

Controls and Connections

Unit has no physical controls. All configuration via serial commands.

Cable Pinout (6-pin):

Pin	Function	Wire Color
1	Power Ground	Black
2	NMEA Out + / RS-232 TX	Brown
3	NMEA In + / RS-232 RX	Red
4	Power Input (6-40 VDC)	Orange
5	NMEA Out -	Green
6	NMEA In -	Blue

LED Indicators: Solid green = tracking; Blinking green = acquiring; Off = no power.

Connecting to Devices

Connect to PC, chartplotter, autopilot, or other NMEA-compatible device.

1. Turn off power to all devices before connecting.
2. Match cable pins to device input (refer to device manual).
3. For RS-232 to PC: Use appropriate serial cable or USB-serial adapter.
4. Apply power and verify data stream with terminal software.

Tip: Use shielded cable for long runs to reduce interference.

Operation Modes

Normal operation: Provides continuous position, velocity, and time data.

1. Default Mode: Outputs all standard NMEA sentences at 5Hz.
2. Configuration Mode: Send proprietary Garmin commands via serial port to change settings (baud rate, update rate, NMEA sentences).
3. Simulator Mode: For testing without satellites (enabled via command).
4. Power Save: Not applicable; unit runs continuously when powered.

WARNING! Do not send configuration commands during critical navigation.

NMEA Output

Default NMEA 0183 v3.01 sentences transmitted:

• GGA: Time, position, fix type, satellites used.
• GLL: Latitude, longitude, UTC time.
• GSA: GPS DOP and active satellites.
• GSV: Satellites in view.
• RMC: Recommended minimum specific GPS/Transit data.
• VTG: Course and speed over ground.
• ZDA: Time and date.

Sentences can be enabled/disabled via configuration commands.

Care & Maintenance

Wipe exterior with damp cloth if dirty. Ensure connector seals are intact.

CAUTION! Do not disassemble unit. No user-serviceable parts inside. Keep connectors clean and dry.

Regulatory Information

FCC Part 15: Class B digital device. Complies with FCC rules. Operation subject to conditions: (1) device may not cause harmful interference, (2) device must accept any interference received. Contains GPS receiver regulated under ITU-R M.823-3. For support, visit www.garmin.com or contact Garmin International at 913-397-8200.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power LED	Power connection	Check voltage (6-40 VDC); verify polarity; check fuse.
LED blinking, no fix	Satellite acquisition	Ensure clear view of sky; wait up to 5 minutes; check for interference.
No data output	Baud rate mismatch	Verify host baud rate matches GPS (default 4800); check cable connections.
Inaccurate position	WAAS/EGNOS status	Ensure WAAS/EGNOS enabled; check for obstructions.
Intermittent data	Cable/connector issue	Inspect cable for damage; ensure connector fully seated and dry.

Reset: Power cycle unit. For factory reset, send proprietary reset command.

Service: Contact Garmin Product Support. Unit is not field repairable.