Access To The Sim (Subscriber Identity Module) Card; Protection From Heat; Visibility Of Diagnostic Leds; Cable Length - CalAmp LMU-5541 Hardware And Installation Manual

Hardware installation manual (22 pages)

Table of Contents

9/28/23, 4:30 PM

When dealing with combination antennas, it is more important to considered GPS performance over Comm performance. GPS signal strengths are much lower than those

typically seen by cellular networks supported by the LMU. In order to maximize the performance the LMU should have a clear view of the sky as possible. When

installing the GPS antenna in a vehicle, make sure that there are as few obstructions as possible close to the LMU that might block the view 360° to the horizon. As with

stand-alone GPS antennas, nothing should not block the combination antenna beyond 5° above the horizon with the best location being near the center of the roof. For

more covert installs, directly under the front or rear-windshields are also acceptable.

6.2.3 Access to the SIM (Subscriber Identity Module) Card

When used in a GSM/GPRS/LTE network, each LMU uses a Subscriber Identity Module (SIM) card, which should be inserted before you install the LMU for the first

time. The SIM card is attached to the main-board inside the housing of the LMU unit.

At some future time, you might need or want to replace the SIM card with a different one, so try to install the LMU in such a way that the cover can be removed to make

the SIM card accessible.

6.2.4 Protection from Heat

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. The maximum

temperature that can be tolerated by the LMU is described in the LMU Environmental Specifications section.

6.2.5 Visibility of Diagnostic LEDs

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.

You may find it useful to be able to view the LEDs periodically to make sure that the LMU is operating properly. If at any time you should encounter a problem with the

LMU, you may need to read the LEDs in order to troubleshoot the problem. If you cannot fix the LMU yourself, you will need to provide the LED information to CalAmp

customer support.

For information about how to interpret the LEDs, see the Status LED Behavior section.

6.2.6 Cable Length

The RF cables which are provided for connecting to the LMU antennas should be used at the length provided. Do not cut cables. Instead, coil any excess cable length,

making sure not to crimp or flatten the antenna cable.

6.2.7 Moisture and Weather Protection

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.

6.2.8 Preventing Accidental or Unauthorized Modification

If you anticipate that fleet drivers or others might interfere with the LMUs once they are installed, take steps to be sure that it is not easy to disconnect the antenna wiring,

remove the LMU from its power source, etc.

Two common methods are the use of Tamper Proof Sealant or creation of PEG Script to detect power loss or GPS antenna disconnections.