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Message ID: 2517     Entry time: Fri Jan 15 18:53:05 2010
Author: josephb,peter,koji 
Type: Update 
Category: Computers 
Subject: Attempted locking with Megatron replacing ETMY front end 

This afternoon we attempted to lock the interferometer using Megatron insteady of the usual ETMY front end.

We attempted it once, found the alignment seemed particularly bad, then realized we had forgotten to add the QPDs.  In the process of adding the QPDs to the tst.mdl file, we realized I (Joe) should have been looking at the iscNetDsc.h file, not the iscNetDs40m.h file for the RFM memory structure.  The only major difference was the memory location of where the qpd information gets passed.

We added QPDs to the tst.mdl file, writing to the RFM network with the QPD pitch, yaw and sum values.

We also added normalization to the oplev, by dividing the OL pitch and yaw values by the OL sum value in the tst.mdl file.

The lscPos, ascPit, ascYaw were working properly, although we did have to poke at the ascPit and ascYaw values once before they started reading properly at Megatron (they started at -1e20).  We think the RFM card may have started in an odd state, and without something causing the ascPit and ascYaw values to change, it never updated.

At the end of the day, the interferometer was locked for a few seconds.  There is are still some issues to be worked on, but its progress.

Koji returned everything back to normal operations after the test.

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