Howard Fenker's notes from installation of now collimator contollers (S6961). logbook.txt
Setup and programs initally downloaded to controllers. download.001
Handy commands and info:
1. Connect to iochc10 via terminal server: telnet hctsv5 2002
2. "Warm boot" of controller (since cable connected to optilogic box disconnected): ColTestCmd "5RS ", 0
Note space between S and close quote. "5" is the collimator being addressed.
3. Send single collimator "HOME": ColTestCmd "5RN2 ",0
Runs program "2" on collimator 5.
4. Get all info in RAM: ColTestCmd "5UA ",2
Figure showing collimator layout, HOME positions and ranges of motion (courtesy HCF).
Visual inspection of collimators - updated September 23, 2008
After investigating the cause of the "grinding" sound coming from collimator 6 when going "HOME", discovered that the drive current from the controller was set to 3.6 A (HCF notes suggested this is bad - should be 2.6 A). Setting to 2.6 A, collimator 6 behavior changes slightly - so updated photos below.
Picture on left shows collimators at -2.3 cm, right shows collimators at -2.35 cm.
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This photo shows collimators driven to -2.1 cm - the sound of grinding was clear. Visually looks much like as shown for -2.3 cm. Conclusion is that -2.35 cm is the best "safe" starting point.
Visual inspection of collimators (September 17, 2008)
Spring 2008, non-reproducibility of collimator 6/7 positions (see fig.) made me suspect they were colliding. Perusing old logbooks suggested that this could/would happen at positions closer to beam than -2.3 cm. Below is a brief summary with photos of what I found when collimator box was opened.
Picture 1: Collimators in retracted position - as found upon initial inspection. Note the opening is cocked relative to the collimators. I think the collimators are properly aligned though.
Picture 2: Collimators in "HOME" positions. Only collimators 1 and 2 are visible.
Picture 3: Collimator 5 in. Note nice beam strike mark.
Picture 4: Collimators 6 and 7 sent to "-2.0" cm. There was an obvious grinding sound as they got very close together - clear sign that they were colliding. Note that there still apears to be a little space between the collimators proper, but the bottom of the frame is in contact.
Picture 5 and 6: Here I sent collimators 6 and 7 "HOME" again, and then to -2.3 cm. There was no obvious grinding sound, but it looks again like the frame is touching at the bottom. For comparison, picture 6 shows the collimators at -2.35 cm. There is visible space at the bottom frame. Also, the vertical shift between colls. 6 and 7 for Picture 5 is not present for Pciture 6.
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Picture 7: Collimator 5 "IN" with collimators 6 and 7 at -2.3. From this perspective, it appears collimator 5 completely defines the acceptance with 6 and 7 as far in as they can go.
