krishna.venkateswara@LIGO.ORG - posted 10:31, Friday 12 August 2016 - last comment - 13:39, Friday 12 August 2016(29057)
NN Array L4C 7 and 8 swapped temporarily
Krishna,
Jenna and I had noticed that L4C 7 didn't appear to be working. L4C is close to the c-BRS, so it would have been good for comparison. In order to test if it was the instrument or the electronics, I temporarily swapped the cables with those of L4C 8 going in to the SUS rack at the LVEA. Now L4C "7" appears to be working and L4C "8" is not, indicating that the problem must be on the instrument side (or the pre-amp, I guess?). I'll swap it back in the afternoon.
Cables replaced in original configuration.
After looking at a different working L4C output (5), I think I was wrong about the instrument being faulty. It looks like the L4C was working when I swapped the cables, suggesting that the problem must be on the electronics side.