ECR Title: ECR: Acquisition of green arm transmitted signals in ASC front-end	DCC No: E1400047
Date: 01/30/2014
Requester: Stefan Ballmer Daniel Sigg	Impacted Subsystem(s): ALS ASC
Description of Proposed Change(s): Add DB9 cable from ALS PDC concentrator 3 (D1201345, LHO S/N 1300240), outputs 1-4 (in rack ISC-R4, slot U20 back) to ASC ADC card 3, channel 25-28 (Rack ISC-C1, slot 33 front, port 7) [D0902783, LHO S/N S1102794]. This cable provides the following signals to be digitized by the ASC (see D1100683): PD_ALS_LASER_IR, PD_ALS_LASER_GR, PD_ALS_TRANS_X, PD_ALS_TRANS_Y
Reason for Change(s): The arm initial alignment (dither alignment) code needs the green arm transmitted signals to be available in the ASC front-end. Those signals are currently only available in the Beckhoff corner system. A DB9 cable and 4 ADC channels are required to make the signals available. Note: CH 17-24 on ASC ADC card 3 have been taken up by WFS DC signals, but are not in document T1100472 yet.
Estimated Cost: the cost of the cable, 4 ADC slots
Schedule Impact Estimate:
Nature of Change (check all that apply): Safety Correct Hardware Correct Documentation	Improve Hardware 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: _DB9_cable_ Future units to be built	Impacted Documentation (list all dwgs, design reports, test reports, specifications, etc.): T1100472 E1200408 D1100683
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