Technical Manual

Table Of Contents
48 D C U M a i n t e n a n c e & O p e r a t i o n M a n u a l
Troubleshooting
Verify LED conditions match the information indicated in the following
table.
Global Positioning System (GPS) Card
Verify the GPS board is securely inserted into the backplane.
Verify the gold cellular cable connector is hand tight.
Perform more in-depth troubleshooting using the Global Navigation Satellite
System (GNSS) menu. Refer to Global Navigation Satellite System (GNSS)
Menu.
N
OTE
Commands 1 and 2 disable GPS functionality. Command 4 allows you to adjust
the sensitivity threshold for using satellite data. Commands 4 and 5 provide
information regarding how many satellites you are connected to.
Component Function State / Condition
SW1 Switch Resets logic to cellular card
(similar to power failure)
SW2 Switch Internal/Engineering use only
LED 1 Red TX LED Flashing (normal) - Indicates
DCU transmit line to M2M
module
LED 2 Red RX LED Flashing (normal) - Indicates
activity on DCU receive line
from M2M module
LED 3 Red LED ON (normal) - 5 FDC supply
is running
LED 4 Red LED Cellular activity status
LED 5 Red LED GPS activity status
LED 6 Red LED VAUX - Janus cellular card
only