keita.kawabe@LIGO.ORG - posted 12:02, Friday 25 January 2019 - last comment - 14:35, Friday 25 January 2019(46641)
Acausal EPICS timestamp for HAM6 fast shutter
In the attached, top two traces are EPICS of the HAM6 fast shutter readback (top is the state of the shutter, next one is the trigger voltage, threshold is set to 2V). According to these, the shutter was triggered between -0.2 and -0.13 second.
If you look at the bottom two traces (ISI sensors to listen to the banging of the toaster and OMC PZT voltage readback), the actual triggering time was at around 0 second.
Images attached to this report
Comments related to this report
The top two are beckhoff channels, the bottom ones are from the RGC. We have seen the timing between the two systems be off by large fractions of a second.