Filter
Top Products
7870 Interfacility Link Installation and User’s Guide page 25
Foxcom proprietary information
4 Troubleshooting
The 7870D Interfacility Link unit was tested before it left the factory.
However if you are experiencing difficulties see the list below for
possible solutions. if you are still experiencing problems, attempt to
isolate and identify the malfunctioning unit before consulting
Foxcom’s technical support.
Table 8 Troubleshooting the Transmitter
Problem Possible Cause
1. Laser LED not on a. No DC power to the unit. Possible
power supply problem or AC power
input problem. Check the power
supply fuse.
b.Verify LSRI monitor is between -4.2
and -4.8VDC. If not, laser may have
overheated. Disconnect power or
remove plug and allow to cool. Try
again with better airflow.
c. If an optical power meter is avail-
able, measure the optical power out
of the transmitter. The power
should between 0.5 mW[-3 dBm]. If
an optical power meter is not avail-
able, use another receiver to deter-
mine if there is optical power
emerging from the transmitter (use
a 5 meter jumper cable). If there is
no optical power, then the transmit-
ter unit is malfunctioning.
If any or all the above are not within
the guidelines, the transmitter unit is
faulty.
2. The RF LED is not
lit
The input signal is less than -28 dBm;
verify RF signal strength [RSSI] is≤0.2
VDC. [See
Table 4 7870T Transmitter
Pinout
on page20]. Even if slightly out
of range, the unit may still function,
although it will register an alarm
condition.
3. RF LED illuminated
- with no input
signal
Unit may be receiving stray RF “pick
up”. Solution: provide RF input or use
necessary termination input.`