Cisco Model GS7000 4-Port Node 1 GHz with 42 54 Split Installation Guide

 

OL-29643-02 

161 

 

 

 

These notes apply to the previous troubleshooting flowchart. 

1 

Recommended RF input levels are: 

 

Headend transmitter module: 14 dBmV 

Note: Based on 79-channel loading. The input will increase as the 
channel loading decreases. 

2 

The range for optical light input 
level is -10 to +3 dBm which 
converts to 0.1 to 2.0 V DC. The 
optimum operating range is -3 
dBm to +3 dBm which converts to 
0.5 to 2.0 V DC. Levels higher than 
+3 dBm can cause the photo diode 
to generate distortions, which add 
to the distortion performance of 
the link, effectively degrading the 
distortion performance. 

The range for optical light input 
level is -10 to -1 dBm which 
converts to 0.1 to 0.8 V DC. The 
optimum operating range is -6 
dBm to -1 dBm which converts to 
0.25 to 0.8 V DC. Levels higher 
than -1 dBm can cause the photo 
diode to generate distortions, 
which add to the distortion 
performance of the link, effectively 
degrading the distortion 
performance. 

3 

Attenuate the light to simulate the amount of light that should be at the 
GS7000 Node and rerun the distortion performance. If the distortion 
performance improves, there is too much light. An inline optical 
attenuator or a coupler with a higher loss can reduce the light, or the 
laser may have to be replaced with a lower launch power.