Observing Operations | Reviews | Survey Management

SDSS Controls & Interlocks Operational Readiness Review
Summary Recommendations
July 14-15, 1999

Reviewers: Ed Bell—NOAO

Jeff Percival—University of Wisconsin

Jeff Peterson—Carnegie Mellon University

Alan Schier—Consultant

Patrick Wallace—Rutherford Laboratory

Overall Issues

1. During commissioning of the system, the project needs a few capable engineers dedicated to the task who spend most of their time on site. These engineers need equipment, long periods of access, and technical support.

2. A larger building is vital in order to allow efficient debug and testing of the telescope.

3. The project needs an on-site system engineer to prioritize and coordinate the work necessary to bring the telescope to an operational state. In the sense intended here, a systems engineer is a technical person.

4. The project needs a project manager and a project management plan.

5. The noise in the various sensors must be addressed immediately. In particular, work on the servos is a much lower priority until the noise in the axis encoders is eliminated.

6. The variety of the computing hardware and software systems is of concern. The project must plan for the case where a critical person is not longer available. This plan should include instructions for rebuilding executables. These instructions must be periodically exercised by the person who is responsible at the time.

7. It appears that the requirement for the speed of the azimuth axis has been misinterpreted. A modest increase in the maximum speed should be easily feasible with the existing hardware and would dramatically reduce the size of the zenith blind spot.

8. The source of the axis runaways must be found and corrected.

9. An axis over speed detection interlock must be implemented.

10. The design of the TPM and utility software should be internally reviewed, decided upon, and documented. The implementation should then proceed quickly.

11. The project needs to generate and implement a policy regarding the bypassing of interlocks.

12. It appears that there is some risk to the telescope and primary mirror in the event that the telescope runs into a hard stop or the windscreen at zero degrees elevation.

13. A slip detection system should be implemented. A procedure for recovery from a slip fault should be decided upon and formalized.

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