This is a 2 hours trend when the end PDH signal was offloaded to the BSC6 HEPI yesterday (see alog 6862).

This worked good so far --- the end laser stayed locked for more than an hour without an obvious sign of misalginment.

Although we do see drift in the ETMY oplev signal as the amount of the offload increases. Since the alignment of the arm stayed good, this could be a longitudinal to angle coupling of the oplev itself.