LMU-4230 Install Guide

device Specifications

Preparing for installation

Be sure you have received all the LMU components you need. This must include:

• The LMU to be installed
• A power harness
• GPS Antenna
• Comm Antenna
• Optional Components:
  • Input and output cables
  • Relays
  • LMU peripherals (i.e. Serial adapter, ioPOD, BTA, TetheredLocator)
  • Host serial devices (e.g. PDAs, laptops, other serial devices)

Plan the installation

Verify power, ground and ignition. Be sure to check each source to ensure that the proper signaling exists. The dimensions of the LMU should be taken into account as well. Whether you intend to place the LMU under a seat or into a cavity behind the vehicle's interior molded trim, be sure the LMU will fit before drilling any holes or running cable. 

• Be certain that the cables running to the LMU will not be bent or constricted. Damage to the cables may impede the LMU's performance.
• It is best not to place the LMU unit in an unusually warm location such as directly near heater vents, near hot engine components or in direct sunlight. 
• Status LED lights on the front of the LMU unit can provide valuable information about the operation of the LMU. When feasible, attempt to install the LMU in such a way that these lights can be seen with reasonable ease. 
• The LMU unit must be located where it will not be exposed to moisture or water. In a typical installation inside a vehicle this is not commonly thought to be a concern; however, it might be best to avoid locating the LMU below a car's cup holders, or where rain might easily splash into the compartment when a door is opened. 

Typical connection sequence

1. Attach the cable from the GPS antenna
2. Connect the cable from the Comm. antenna
3. Connect any peripherals to the LMU
4. Plug in the power harness

Placement of antennas

There are effectively three options for placements of an antenna:

• Roof-mount (magnetic or thru-hole)
• Glass-mount
• Covert (e.g. under the seat, dash, etc...)

Comm antenna

The comm. antenna must be located at least 20 cm away from the vehicle passengers, other personnel, or bystanders in order to comply with FCC radio frequency exposure limits. Typically, the Comm antenna used by the LMU for wireless service is a standard 3-dB gain whip. It mounts with standard mounts (i.e. thru-hole, magnetic mount or peel and stick) and requires a ground plane to work properly. If possible, it should be located at least 3 feet from the GPS antenna. Ensure that the cable does not get crushed during installation. 

GPS Antenna

In order to maximize the performance of the LMU the GPS antenna should have a clear view of the sky. When installing the GPS antenna on a vehicle, make sure that there are no obstructions close to the antenna that might block the view 360 degrees to the horizon. Things like air horns, lights, vents, etc... should not block the antenna beyond 5 degrees above the horizon. The best location is usually near the center of the roof; however it is also desirable to locate the cellular antenna as far from the GPS antenna is practical.

Installation

Typically, the LMU should be placed under the passenger seat or dashboard of the vehicle. Attach the LMU to the solid body of the vehicle, not to plastic panels. The LMU can be placed out of sight by removing interior trim and molding to expose available space, then replacing the trim once the LMU is in place.

Connect power, ignition, and ground

The power input (red wire) must be connected to a constant (un-switched) +12 VDC or +24 VDC supply; preferrably, connected directly to the vehicle battery terminal or as close to it as possible. This connection point should be fuse protected to not more than 5 Amps. The ignition input (white wire) must be connected to the vehicle ignition or another appropriate key operated line, such as ACCESSORY, ensuring that power to the ignition wire is available only when the vehicle ignition is on. The ground line (black wire) must be connected to chassis ground.

Failure to connect these lines in the manner described may result in discharge of the vehicle battery.

For best results, it is strongly recommended that the LMU connection be on its own circuit. Connect the power input directly to the vehicle battery if possible and protect the circuit with an inline fuse. If you must connect through the fuse box, use standard commercial wiring practices to create a permanent installation rather than using press-in fuse clips or other temporary measures.

DO NOT connect the power cable to the LMU at this time.

Place the GPS antenna

The GPS antenna must have a clear view of the sky. Mount the GPS antenna on the vehicle's highest point (for example, the roof of a car). Make sure that there are no obstructions close to the antenna that might block the view 360 degrees to the horizon. Air horns lights, vents, etc... should not block the antenna beyond 5 degrees above the horizon. 

Kinks or knots in the antenna cable can prevent the GPS receiver from operating properly. When laying out the antenna cable, take care that the cable is not subjected to crushing or strain. 

The ideal location is typically near the center of the vehicle's roof. However, it is also desirable to locate the cellular antenna as far from the GPS antenna as possible.

Mount the comm. antenna

When using seperate Comm and GPS antennas, it is best to locate the Comm. Antenna at least 3 feet from the GPS antenna. Ensure that the cable is not crushed during installation or normal vehicle operation. 

Again, the Comm. Antenna must be located at least 20cm away from vehicle passengers, other personnel, or bystanders in order to comply with FCC radio frequency exposure limits.

The physical installation of the LMU hardware is now complete.