Installation Guide

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.
5.5.3 Typical Connection Sequence
Connect any peripherals to the LMU
Plug in the power harness.
The physical installation of the LMU hardware is now complete.
5.6 Installation Verification
In many cases it is desirable to verify that an installed HMU-3640™ is working properly. That is, installers should verify that the
GPS and
communications functions of the HMU-3640™ are working properly before departing the installation site. In more robust cases,
some key
configuration settings such as the Inbound Address and URL should also be verified.
Note that these processes are all based on issuing AT Commands to the HMU-3640™. It is expected that installers will have
access to a serial port
expansion cable and a laptop or PDA capable of a terminal connection. Alternatively, an SMS message can be sent to an HMU-
3640™ to obtain
its current status.
5.6.1 Comm Verification
Installers should first verify that the HMU-3640™ has been acquired and has registered to the wireless network. This may be
verified in one of
two ways. First, installers may look at the Comm LED (i.e., the one closest to the SMC antenna connector). If this LED is solid,
then the LMU has
registered to the network and established a data session.
If the LED is not visible, then Comm may be verified using an AT Command:
ATIC
Depending on the wireless network being used something similar to what is shown below will be displayed. It is important to
verify that 'Yes'
values are displayed at the top for Data and Network registration and the correct APN is displayed.
Radio Access : GSM
Network Reg. : Yes, Home
Data Reg. : Yes, Home
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Connection : Yes
RSSI : -97 dBm
BER : 99
Channel : 737
Cell ID : 3441
Base Station ID : 40
Local Area Code : 31003
Network Code : 410
Country Code : 310
IMEI (Modem S/N): 351802055396182
IMSI (SIM ID) : 310410202524377
ICC-ID (SIM S/N): 89014102212025243778
Phone Number :
GPRS APN : ISP.CINGULAR
Maint. Server : maint.vehicle-location.com(216.177.93.246):20500
Inbound Server : (0.0.0.0):20500
Dual Comm : routing id=0, log cid=0, modem type=21, inbnd index=0
OK
If any of the responses return Not-Acquired or Not-Registered (and the APN is correct), the wireless network operator should be
contacted for
further troubleshooting.
Please note that it may take several seconds (or longer) for the HMU-3640™ to communicate with the modem and acquire the
wireless network.
5.6.2 GPS Verification
The next step is to verify that the GPS receiver is seeing enough satellites to obtain a valid GPS position. Again, installers have
two choices on
how to perform this verification. First, like the Comm Verification, there is a GPS status LED (i.e., the one closest to the SMA
connector). If this
LED is solid, then the LMU has found GPS service.
If the LED is not visible then GPS service may be verified using an AT Command:
AT$APP GPS?