Following the recovery of this morning, there are alerts in the DMS (triggered only in LN3 mde): some DSPs from different suspensions are not properly synchronized:
- the NE, WI and PR MIRrors have a different synchronisation that before the timing issue of last Monday. In particular the case of the NE mirror will introduce large errors in the reconstructed h(t) data.
- the synchronisaton of the NE and WE MARionnettes is not activated since few months, so no information on them. But since they are not used for the controls, it has no impact on Hrec.
The first two VIM plots from today show the current status for the mirrors and for the marionettes (the phase is computed at a line injected at 2012 Hz):
- NE Mirror DSP off by 50 µs --> impact on Hrec
- WI Mirror DSP off by 50 µs
- PR Mirror DSP off by 50 µs
- SR MIrror DSP off by 25 µs
- WI Marionette DPS off by 25 µs --> impact on Hrec
The figures 3 and 4 show the monitoring data on Monday 17 November: the synchronisation of the different DSPs changed at different times in the afternoon.
The last figure shows the current bias on hrec (supposed to be unbiased) : this has a huge impact on the phase bias, (apparently not on the h(t) amplitude, which I do not undertand at first sight). The phase bias looks consistent with ~50 µs bias around 250 Hz.
At least the NE mirror and WI marionette DSPs should be resynchronized as soon as possible to have a correct reconstructed h(t).
