ECR Title: IO Extender Inline On-Off Switch	DCC No: E1300855-V1
Date: 11/07/2013
Requester: David Kinzel	Impacted Subsystem(s): ALL at LHO that are participants of the nature of owning one or more IO Extenders.
Description of Proposed Change(s): Insert into the DC path of every IO extender (D1001715) an inline on-off switch. This is done at LLO.
Reason for Change(s): Sometimes the IO extenders need to be truly turned off. In addition, the DC pigtails need some sort of strain relief.
Estimated Cost:
Schedule Impact Estimate: None. This is not part of aLIGO, so “schedule” is not an applicable roadmap. However there is an impact on operations. It will take approximately 5 minutes per IO chassis to install this hardware. Whatever the cost is to the rebooting of the front ends will be a multiple of the multiple of IO extenders shut down at any given event.
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: ___1/1/2014_________ 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.): Since there is no documentation for how to hook up an IO extender, there is probably no impact on it.
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