ECR Title: Add critical duotone readback channels in science frames at 16kHz for OMC and PCAL	DCC No: E1500373-v1
Date: 2015/08/28
Requester: Keita Kawabe	Impacted Subsystem(s): OMC/ISC/CAL
Description of Proposed Change(s): Add ADC0 CH31 (duotone monitor channel) in science frame for IOPs that monitors OMC DCPD, Pcal X and Pcal Y. Record them at 16kHz. For the OMC DCPD ADC monitor, such channel does not exist yet in the user model, so one filter will be added in the common OMC model to make the channel. I propose IFO:OMC-ADC_DT-OUT_DQ as the channel name, following the naming of corresponding 64k IOP channel IFO:IOP-LSC0_ADC_DT_OUT_DQ. For Pcal X and Y such channels already exist. The channel name is IFO:CAL-PCALX_FPGA_DTONE_OUT_DQ for X and IFO:CAL-PCALY_FPGA_DTONE_OUT_DQ for Y. These channels are merely added to the science frame.
Reason for Change(s): The proposed channels allow one to perform full analysis of aLIGO timing calibration retroactively, e.g. in the event of potential first detection. Without these channels, the only available timing check is a simple zero-crossing based check performed in each IOP which doesn’t use the full benefit of duotone (e.g. zero-crossing cannot detect a large timing jump, however unlikely that is).
Estimated Cost: Three more 16k channels in the science frame. One more 16k channel in the commissioning frame.
Schedule Impact Estimate: None. Model change could be done in the background, and once the models are ready they could be installed in one maintenance period.
Nature of Change (check all that apply): Safety Correct Hardware Correct Documentation	Improve Hardware Improve Software Improve/Clarify Documentation Change Interface Change Requirement
Importance: Desirable for ease of use, maintenance, safety Desirable for improved performance, reliability Essential for performance, reliability Essential for function Essential for safety	Urgency: No urgency Desirable by date/event: ____________ Essential by date/event: ____________ Immediately (ASAP)
Impacted Hardware (select all that apply): Repair/Modify. List part & SNs: ______________________ Scrap & Replace. List part & SNs:_____________________ Installed units? List IFO, part & SNs: _________________ Future units to be built	Impacted Documentation (list all dwgs, design reports, test reports, specifications, etc.): Impacted Software (list all that apply): Common OMC frontend model. Common PCAL frontend model.
Disposition of the proposed change(s): The disposition of this proposed engineering change request is to be completed by Systems Engineering and indicated in the “Notes and Changes” metadata field in the DCC entry for this ECR. The typical dispositions are as follows: Additional Information Required: in which case the additional information requested is defined. The ECR requester then re-submits the ECR with the new information using the same DCC number for the ECR but with the next version number. Rejected: in which case the reason(s) for the rejection are to be given Approved Approved with Caveat(s): in which case the caveat(s) are listed TRB: the ECR is referred to an ad-hoc Technical Review Board for further evaluation and recommendation. It is the System Engineer’s (or designee’s) responsibility to organize the TRB. The System Engineer (or designee) then makes a technical decision based on the TRB’s recommendation. Links to the TRB’s documentation (charge, memos, final report, etc.) are to be added to the “Related Documents” field for this ECR. CCB: a change request for approval of additional funds or schedule impact is to be submitted to the Configuration Control Board. Links to the CCB’s documentation (CR, etc.) are to be added to the “Related Documents” field for this ECR. Concurrence by Project Management: Acknowledgement/acceptance/approval of the disposition is to be indicated by the electronic “signature” feature in the DCC entry for this ECR, by one the following personnel: Systems Scientist Systems Engineer Deputy Systems Engineer