© 2019 Jackson Labs Technologies, Inc. 5
Micro-JLT GNSS™ User Manual
Quick-Start
Instructions
2.1 Powering Up the Unit
To operate the unit, simply follow these two steps:
1) Connect a 3.3V-compatible GNSS antenna to SMA connector J2. Use an appropriate
lightning surge suppressor on the antenna cable. The Micro-JLT GNSS™ board will supply
a current-limited 3.3V power to the antenna
2) Connect +5.5V (-0.3V/+0.5V) DC Power to J1 pin 10 and pin 12 on the unit, and ground
to pin 2 and pin 9 of J1
[The unit will consume up to 8W of power during oscillator warmup]
The unit will now lock to GNSS signals (Red LED D2 is blinking to indicate that the GNSS receiver
has a proper fix) and will indicate proper lock and no events pending when the Green LED D2 goes
on, with the Red LED D2 intermittently blinking as well. Once the green LED D2 is on, the unit will
output 10MHz with significantly better than 1ppb frequency accuracy.
By default the unit will be set to Position Hold mode, and an antenna position
Auto Survey process is started after power-on that may take up to 3 hours to
finish. The antenna should never be moved when the unit is set to run in
Position Hold mode as this would result in loss of frequency, timing
accuracy, and incorrect GNSS fixes. The unit must be configured to mobile
3D mode using the GPS:TMODe OFF command when used in an
application where the antenna position can move during normal operation.
Using the Auto Survey process and Position Hold mode allows the unit to
over-determine the timing solution. It also allows TRAIM operation which
will result in a higher timing stability and more robust GNSS reception in
challenged environmental conditions such as under foliage, in urban
canyons, etc.
Please note that the GNSS receiver establishes the internal antenna gain right after
power-on, so for proper operation the GNSS antenna should always be connected prior
to turning on the +5.5V prime power.
To Next Page
Loading...