Foxconn Interfacility Link 7870 User Manual

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.

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 

on page 20]. 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.`