As outlined in alog 17077 we should shift the IMC frequency to the reference cavity AOM up by ~450 KHz after we are locked, the common tidal feedback path is engaged and after the green light is no longer needed. To this end an offset has been added after the IMC_F filter module. This way we can use kHz rather than counts. It also employs a ramping feature, so the offset can be turned on smoothly.

New channels are H1:IMC-F_OUT_OFFSET for the frequency offset in kHz, H1:IMC-F_OUT_OFFSET_SW for engaging the offset, H1:IMC-F_OUT_TRAMP for the ramp time in sec, H1:IMC-F_OUT_RAMPING for the status of the ramping process, and H1:IMC-F_OUT_MONITOR as the new error signal for the common tidal servo. H1:IMC-F_OFFSET_OUT is available as a new fast testpoint which includes the offset.