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Message ID: 2539     Entry time: Thu Jan 21 15:16:16 2010
Author: josephb, koji 
Type: Summary 
Category: Computers 
Subject: Megatron used to lock Y arm 

We succeeded in having a stable single arm (Y) lock using Megatron to replace c1iscey.

Now the lock with megatron is pretty easy. Really. It's very cool.

As we saw the oscillation of the YARM servo, we temporalily increased the gain of TRY filter by a factor of 2 (0.003->0.006). Also decreased the gain of YARM servo by the factor of  2 (1->0.5). This makes the servo gain reduced by a factor of 4 in total. This change seemed to come from the change of the ADC/DAC range.

We finally fixed the hi-gain pd transmission communications from Megatron to the c1lsc by tracking down the correct RFM memory location (which is unhelpfully labeled as a qpd channel in both losLinux and lsc40.m).  The memory location is 0x11a1e0, and is refered to as qpdData[3].

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