Motion Set points

Wiki > The Backend System > IOCs > Motor IOCs > Motion Setpoints

Motion set points allow you to label set positions for a motor, current either 1 axis or 2 axes. The code for this is in support in the directory motionSetPoints. The configuration for a motion set point is in to parts:

1. St file called motionsetpoints.cmd which sets up the db file which is stored in the configuration under the motor name:
   • galil is Settings\config\<host name>\configurations\galil
   • mclennan is Settings\config\<host name>\configurations\mcleanan
   • sm300 is Settings\config\<host name>\configurations\<sm300 ioc name e.g. SM300_01>
2. The positions which are referenced from the st file. are stored in Settings\config\<host name>\configurations\motionSetPoints

The motionsetpoints.cmd contains the following lines:

1. Point at motion setpoint config: epicsEnvSet "LOOKUPFILE<X>" "$(ICPCONFIGROOT)/motionSetPoints/<motion setpoint file>"
2. Configure setpoints: motionSetPointsConfigure("LOOKUPFILE<X>","LOOKUPFILE<X>")
3. Load Motion Setpoint Records:
   • For 1D setpoint not using an axis macros dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db","P=<motion set point prefix>,TARGET_PV1=<motor prefix>,TARGET_RBV1=<motor prefix>.RBV,TARGET_DONE=<motor prefix>.DMOV,TOL=<tolerance>,LOOKUP=LOOKUPFILE<X>")
   • For 2D setpoint not using an axis macro dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db","P=<motion set point prefix>,TARGET_PV1=<motor prefix>,TARGET_RBV1=<motor prefix>.RBV,TARGET_PV2=<motor prefix2>,TARGET_RBV2=<motor prefix2>.RBV,TARGET_DONE=<motor prefix>.DMOV,TARGET_DONE2=<motor prefix2>.DMOV,TOL=<tolerance>,LOOKUP=LOOKUPFILE<X>")
   • For 1D setpoints using an axis dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db","P=<motion set point prefix>,NAME1=<name1>,AXIS1=<axis1>,TOL=<tolerance>,LOOKUP=LOOKUPFILE<X>")
   • For 2D setpoints using axes dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db","P=<motion set point prefix>,NAME1=<name1>,AXIS1=<axis1>,NAME2=<name2>,AXIS2=<axis2>,TOL=<tolerance>,LOOKUP=LOOKUPFILE<X>")
4. Load In Position records: This is a dbLoadRecordLoop instruction (one for each dbLoadRecords above), which loads an extra db file for one setpoint per iteration, which contains a record for indicating whether the motor is at this particular setpoint. The line should look as the corresponding line from above, except:
   • replace dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db" with dbLoadRecordsLoop("$(MOTIONSETPOINTS)/db/inPos.db"
   • add the loop arguments at the end (currently hardcoded), e.g.: LOOKUP=LOOKUPFILE<X>, "NUMPOS", 0, 30)
5. A blank line at the end

Where:

• X - enumeration of lookup files, e.g. 1, 2
• motion setpoint file - the lookup motion setpoint file
• motion set point prefix - the prefix you want to create for the motion setpoint, e.g. $(MYPVPREFIX)LKUP:MON3:, $(MYPVPREFIX)LKUP:SAMPLE:, $(MYPVPREFIX)LKUP:ANALYSER: (ending in a colon)
• motor prefix - the prefix of the first/only motor e.g. $(MYPVPREFIX)MOT:MTR0601
• motor prefix2 - the prefix of the second motor e.g. $(MYPVPREFIX)MOT:MTR0601, $(MYPVPREFIX)MOT:ANALYSER:THETA
• tolerance - tolerance with which the position has to comply with the positions in the lookup file
• axis1 - the axis to use for the first/only motor e.g. $(MYPVPREFIX)MOT:SAMPLE:LIN
• name1 - the name of axis 1, e.g. "linear" (defaults to axis1)
• axis2 - the axis to use for the second motor e.g. $(MYPVPREFIX)MOT:SAMPLE:ROT
• name2 - the name of axis 2, e.g. "rotational" (defaults to axis2)

For examples see Larmor, Demo or SANDALS.

The lookup motion setpoint file has the following format:

# Commnet, lines starting with hashes are comments
<label> <coord 1> <coord 2>
<label> <coord 1> <coord 2>
...
<label> <coord 1> <coord 2>

Field are separated by spaces. The fields are:

- `label` is the text label for the setpoint
- `coord 1` is the set point for the first/only motor
- `coord 2` is the set point of the second motor (or not included if it is 1D set point)

Often these files are calculated from xml files using the sample changer support module.

Example file

$(IFIOC_GALIL_04) epicsEnvSet "LOOKUPFILE1" "$(ICPCONFIGROOT)/motionSetPoints/monitor3.txt"
$(IFIOC_GALIL_04) motionSetPointsConfigure("LOOKUPFILE1","LOOKUPFILE1")
$(IFIOC_GALIL_04) dbLoadRecords("$(MOTIONSETPOINTS)/db/motionSetPoints.db","P=$(MYPVPREFIX)LKUP:MON3:,NAME1=linear,AXIS1=$(MYPVPREFIX)MOT:MONITOR3,TOL=0.1,LOOKUP=LOOKUPFILE1")
$(IFIOC_GALIL_04) dbLoadRecordsLoop("$(MOTIONSETPOINTS)/db/inPos.db","P=$(MYPVPREFIX)LKUP:MON3:,NAME1=linear,AXIS1=$(MYPVPREFIX)MOT:MONITOR3,TOL=0.1,LOOKUP=LOOKUPFILE1", "NUMPOS", 0, 2)

OPI

There are two motion set point OPIs:

• Motion Set Point (Few): For setpoints with only 3 or 4 positions
• Motion Set Point: For setpoints with many positions