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Entry  Thu Oct 14 00:53:44 2010, kiwamu, Update, SUS, what's wrong with MC2 OSMEs.png
    Reply  Fri Oct 15 22:16:22 2010, kiwamu, Update, SUS, what's wrong with MC2 
Message ID: 3731     Entry time: Fri Oct 15 22:16:22 2010     In reply to: 3711
Author: kiwamu 
Type: Update 
Category: SUS 
Subject: what's wrong with MC2 

[Yuta, Suresh, Rana and Kiwamu]

 The DC alignment problem of MC2 was fixed.

There were some loosely connected cables on the backside of a VME rack which contains the MC2 SOS driver.

We pushed those connectors to make them tightly connected.  And then the problem disappeared.

 


(voltage unbalance on coils)

 Before fixing it Yuta opened the satellite box and measured the voltage across the coils using a voltmeter.

At that time UL and LR showed 20 times smaller voltages than that of the other two when we moved the DC alignment slider from min. to max. on the medm screen.

This behavior is exactly consistent with the wired motion of a beam spot which we saw when we were aligning MC2. 

 

(diagnostic using optical lever)

 After pushing the connectors, we made an optical lever using a red laser pointer in order to check the actual motion of MC2.

We confirmed that MC2 respond correctly to the alignment slider.

Quote:

 2010:Oct.14th:

It turned out that the DC alignment of MC2 from epics doesn't helathily work.

For example, the pitch slider does drive the yaw alignment as well.

 

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