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TTU-12x0 Hardware & Installation Guide - PULS Wiki
https://puls.calamp.com/wiki/TTU-12x0_Hardware_%26_Installation_Guide
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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.
5.2.6 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.
5.2.7 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.
5.2.8 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.
5.3 Installing the LMU in a Vehicle
This section provides instructions for installing an LMU in a vehicle.
Be sure to consider the design decisions described in the previous sections. When you are ready to begin installing the LMU,
follow these steps:
5.3.1 Place the LMU unit in the vehicle.
Typically, the LMU should be placed under the passenger seat or dashboard of the vehicle. LMUs with internal antennas
should be placed to maximize their GPS performance. A typical location include under the dash close to the front wind-shield.
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.
5.3.2 Connect power, ignition, and ground.
The power input (red wire) must be connected to a constant (un-switched) +12 VDC or +24 VDC supply; preferably,
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.
