We aligned and locked Y arm for green:

• installed camera on PSL to monitor green transmission
• aligned green path on the ETMY table to see the beam on the PSL camera
• misaligned ETMY and aligned ITMY to see reflected beam on REFL PD
• installed green transmission PD on PSL
• aligned ETMY and locked YARM to 00 mode

I've switched error channel cable to output monitor. Whitening filter is need for scattering measurements.