1. GONIOMETER SWITCH POSITIONS
Vanik Kakoyan
Hall D Controls Meeting 9-June-2016

2. HOME SEARCH in the XPS Controller
Home search is a specific motion process. Its goal is to find a reference point along the travel accurately and repeatedly. Any motion group must first be homed before any further motion can be executed.
Home search processes available in the XPS controller is set up in the stages.ini configuration file.
Low limit switch
Home switch
High limit switch
Home
CurrentPositionAsHome
Home
MinusEndOfRunHomeSearch
MinusEndOfRunAndIndexHomeSearch
Home
MechanicalZeroHomeSearch
MechanicalZeroAndIndexHomeSearch
Home
PlusEndOfRunHomeSearch

3. Home Search for Goniometer Stages
Motors of the X and Y stages have an Encoder. As Home Search
procedure we defined: MinusEndOfRunAndIndexHomeSearch
Home switch
Low limit switch
High limit switch
Home
First index Before latching to the Low LS
Motors of the Pitch, Yaw and Roll stages have not an Encoder.
Home search procedure is: MechanicalZeroHomeSearch
Low limit switch
Home switch
High limit switch
Home
Somewhere After latching to the Home Switch

4. The Geometry of Goniometer X and Y Stages
In order to check working condition of some switch we have to know the geometry of stage and in which area of the stage find it.
Low limit switch Minus End of Run
Home switch Mechanical Zero
High limit switch Plus End of Run
Home + - B A C
The Distances from Home position to the 3 Switches of X and Y stages was measured using GroupReferencing functions of XPS Controller.
A) GroupReferencingActionExecute (S, LatchOnLowToHighTransition , MinusEndOfRun , )
B) GroupReferencingActionExecute (S, LatchOnHighToLowTransition , MechanicalZero , 0.001)
C) GroupReferencingActionExecute (S, LatchOnLowToHighTransition , PlusEndOfRun , 0.001)
Stage
Unit
< A >
Deviation
< B >
< C > X mm
-0.876
0.002
99.201 Y
-1.106
49.012

5. The Geometry of Pitch, Yaw and Roll Stages
Home switch Mechanical Zero
Low limit switch Minus End of Run
High limit switch Plus End of Run
Home + - A C B
We used several functions:
A) GroupReferencingActionExecute (S, LatchOnLowToHighTransition , MinusEndOfRun , )
B) GroupReferencingActionExecute (S, LatchOnLowToHighTransition , MechanicalZero , )
C) GroupReferencingActionExecute (S, LatchOnLowToHighTransition , PlusEndOfRun , )
The distances from Home position to the 3 switches for Pitch,Yaw and Roll stages:
Stage
Unit
< A >
Deviation
< B >
< C >
Pitch
degree
0.0006
0.0019
Yaw
0.0073
0.0065
0.0168
Roll
0.0146
0.0038
0.0061

6. Distances between Home Positions
Three possible Home positions for each stage.
To change Home Search process during the Experimental Run due to damage of the switch which was used for Homing .
The distances of Home positions are the Transformation parameters (offsets) to calculate the coordinates of Known positions of Goniometer in new coordinate system.
Easy to make all necessary changes in the Goniometer positions control GUI and in the scripts.
Low limit switch
Home switch
High limit switch
Home1
Home2
Home3 A B
Stage
Unit
< A >
Deviation
< B > X mm
100
0.001 Y 50
50.602
Pitch
degree
0.0005
Yaw
0.0071
0.0166
Roll
0.0144
0.0058

7. THANK YOU