(Sheila, Max, Chris)
On Friday we uncovered a snafu with the slow controls cabling at the Y end. The connector labels engraved on the rear panel of the "End 2" EtherCAT chassis (Exhibit A) do not agree with the chassis wiring plan (Exhibit B). Upon opening the chassis it appeared that the internal wiring to the Beckhoff modules was done according to (B), whereas the external cable runs had been connected relying on (A). Here's a table showing the correspondences:
Port | Wiring plan | Rear panel description |
6 | Auxiliary | DC Photodiodes |
7 | PZT Mirrors/PDs/Laser Temp | Auxiliary |
8 | TCS | PZT Mirrors/PDs/Laser Temp |
9 | RF Amplifiers | TCS |
10 | DC Photodiodes | RF Amplifiers |
11 | LSC Demodulators | LSC Demodulators |
12 | Laser Diagnostics | Laser Diagnostics |
This problem came to our attention after we noticed that the fiber PLL slow path (laser temperature) control output was broken. Actually it was just routed onto the wrong cable.
Attached images show the interior and rear panel of the End 2 chassis at the Y end.