DMU380SA Series
User’s Manual
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Doc# 7430-0026 Rev.01
Page 7
GPS Antenna Connection (INS380SA)
2.9
The GPS receiver needs to receive signals from as many satellites as possible. A GPS
receiver doesn’t work properly in narrow streets and underground parking lots or if
objects or human beings cover the antenna. Poor visibility may result in position drift or a
prolonged Time-To-First-Fix (TTFF). A good sky visibility is therefore a prerequisite.
Even the best receiver can’t make up for signal loss due to a poor antenna, in
-band
jamming or a poor RF cable.
The DMU380SA Series unit ships with an external active antenna that must be connected
properly to SMA jack located next to the DB-15 connector. Placing the antenna on a 4
inch or larger ground plane is highly recommended.
IMPORTANT
Place the antenna with optimal sky visibility and use a ground plane. Route the GPS
Antenna RF cable away from sources of radiated energy (i.e. switching power supplies).
No Connection
2.10
During normal operation of the DMU380SA Series, no connection is made to the factory
test pins. These pins have internal pull-up mechanisms and must have no connections for
the DMU380SA Series to operate properly.
Quick Digital interface connection
2.11
On a standard DB-9 COM port connector, make the connections as described in Table 6
