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Message ID: 2370     Entry time: Mon Jul 22 19:31:20 2019
Author: anchal 
Type: DailyProgress 
Category: FSS 
Subject: FF Gain channels converted to physical units 

I found today that all this while, the channel values shown on our FSS_Interface medm screen and used by rmsMonitor.py for gain cycling were somewhat arbitrary numbers. It took me a while to figure out that the channel voltage is 10 times what reaches the AD602 on TTFSS board. Maybe awade knew about this but there was no documentation on this. Anyways it seemed bogus to increase the gain of FSS loops in arbitrary units. I added four more channels with _DB suffix which carry the physical units (in dB) of the Common and Fast gains in FSS loops. The older gain channels are calc channels now which calculate the channel voltage required from dB value. Everything has been tested to work correctly with the changes. My next steps are to step by step check all transfer functions in the FSS loop and find the culprit.

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