The following table describes the EPICS PVs used for executing a +
+The following table describes the EPICS PVs used for executing a trajectory.
Channel access clients should do the following to execute a trajectory:
++Channel access clients should do the following to execute a trajectory:
- Set
Execute=1 - Repeatedly read
Execute, wait for it to go to @@ -556,10 +625,10 @@ trajectory.The execution can fail because the velocity or acceleration is too large, even if the build succeeded, if
-TimeScaleis less than 1.0.
-
-Reading Back a Trajectory
+
++ Reading Back a Trajectory
After a trajectory has been executed it is possible to read back from the MM4005 or XPS the theoretical and actual positions of the motors when each @@ -568,7 +637,9 @@ as the actual positions and the following errors (actual position minus theoretical position) since these are usually of most interest to the user. Obviously the theoretical position can be computed from the actual position and the following error.
-Reading back this information from the MM4005 (but not the XPS) is rather slow, + +
+Reading back this information from the MM4005 (but not from the XPS) is rather slow, but in many cases this does not need to be done for each scan. Once it is established that the following errors are small enough it is possible to execute scans without reading back from the @@ -576,8 +647,12 @@ MM4005 each time. The readback time is determined by the speed of the communications interface to the MM4005. Each point returned from the MM4005 is about 200 characters. Using RS-232 at 19,200 baud this requires 0.1 seconds per point, where the number of points is equal to the number of output pulses. This -is thus 30 seconds for a scan with 300 output pulses.
-The following table describes the EPICS PVs used for reading back a +is thus 30 seconds for a scan with 300 output pulses. The XPS uses FTP over Ethernet +to read the "Gathering.dat" file containing the theoretical and actual motor +positions. The time to copy this file is very short, even for a large number of points.
+ ++The following table describes the EPICS PVs used for reading back a trajectory.
@@ -589,7 +664,7 @@ trajectory.
Readbackbusy Setting this PV to 1 will read back the results of the - trajectory motion from the MM4005. It will be set back to 0 automatically + trajectory motion from the controller. It will be set back to 0 automatically when the readback is complete. ReadStateNactuallongout -The actual number of pulses output by the MM4005. This value + The actual number of pulses output by the controller. This value is normally equal to Npulses, but it could be less if a trajectory did not complete.@@ -642,32 +717,40 @@ trajectory. It can be used to read back this trace buffer even if the previous operation was not a trajectory execution. This can be useful for debugging operations in general. -
-
-Interaction with EPICS Motor -Records
+
++ Interaction with EPICS Motor Records
+The trajectory scanning does not use the EPICS motor records, but rather talks directly to the controller. In order to keep the motor records in -sync with the actual motor positions the SNL program always returns the motors -to their original positions, i.e. the positions where the motor records think -they are, after a trajectory execution is complete. One should not move any -motors on an MM4005 while a trajectory scan is in progress.
+sync with the actual motor positions the SNL program always sends the motors +to the final position in the trajectory scan, i.e. the positions where the motors actually +are, after a trajectory execution is complete. This should not result in any actual +motor motion (except for small following errors), but serves to resynchronize the +EPICS motor VAL and RBV fields with the actual motor positions. +One should not move any +motors on the MM4005 or XPS with the EPICS motor records +while a trajectory scan is in progress. -When a motion is aborted with the
AbortPV it will be necessary ++When a motion is aborted with the
-AbortPV it will be necessary to home the motors and synchronize the motor records with the actual positions of the motors.
-
-Communication with the -MM4005
-The communication with the MM4005 uses asyn. It can be used with either the +
++ Communication with the controller
+ ++The communication with the MM4005 uses asyn. It can be used with either the RS-232 or GPIB interfaces. Debugging can be enabled with the
asynSetTraceMaskandasynSetTraceIOMaskcommands. Communication with the XPS also uses asyn over a TCP/IP socket connection. Debugging can be enabled and disabled in the same way. -The timeout for communication with the MM4005 is set to 30 seconds, because + +
+The timeout for communication with the MM4005 is set to 30 seconds, because some commands can take a very long time to response. This was found to be necessary to allow for the long time it takes the MM4005 to respond to the TB command after a VC command is issued when verifying the trajectory. However, it would probably be @@ -676,12 +759,20 @@ trajectories as a function of
-NelementsandNpulsesand have the SNL program wait that long after sending the VC command and before sending the TB command. These measurements have not been done yet.Hardware Notes
-The synchronization output pulses from the MM4005 are provided on pin 12 of -the DB-25 Auxilliary Connector. We have found it convenient to make a connector -with a short BNC pigtail coming from this pin. This pulse output from the MM4005 -is an open-collector circuit. The maximum rating is 30V and 40 mA.
-When using the pulse output as the channel-advance input of the Struck 7201 +
++ Hardware Notes
++The synchronization output pulses from the MM4005 are provided on pin 12 of +the DB-25 Auxilliary Connector. +The synchronization output pulses from the XPS are provided on pin 12 of +the GPIO2 connector. We have found it convenient to make DB-25 connectors +with a short BNC or LEMO pigtail coming from these pins. The pulse outputs from both +the MM4005 and XPS +are open-collector circuits. The maximum rating in both cases is 30V and 40 mA.
+ ++When using the pulse output as the channel-advance input of the Struck 7201 or SIS 380x multi-scaler some modifications are required. The SIS 380x manual states that with the LEMO TTL input configuration the inputs are pulled up to +5V with 1K Ohm resistors in a resistor pack. For our module the factory @@ -692,15 +783,18 @@ microseconds to go from 0V to the TTL threshold. This slow rise time caused the SIS 380x to double count the channel advance signal most of the time. By replacing the 4.7K Ohm resistor pack with a 200 Ohm pull-up resistor pack the rise time was reduced to about 2 microseconds, and the module does not double -count. 200 Ohms is within the spec of the MM4005, since it will result in a +count. 200 Ohms is within the spec of the MM4005 and XPS, since it will result in a current of 5V/200 Ohm = 25 mA, which is less than the 40 mA maximum.
+
-
-Installation
-The source files for trajectory scanning are in the synApps +
+ Installation
++The source files for trajectory scanning are in the synApps motor module , in the motorApp/ tree. -
+ +
NewportSrc/MM4005_trajectoryScan.st NewportSrc/XPS_trajectoryScan.st Db/trajectoryScan.db @@ -709,227 +803,353 @@ op/adl/trajectoryScanDebug.adl op/adl/trajectoryPlot.adl
-vxWorks startup file
-The following are the comments from the beginning of -
-trajectoryScan.dbwhich describe the macro parameters which must be -supplied in thedbLoadRecordscommand in the vxWorks startup -script.# Database for Newport MM4005 trajectory scanning. -# -# Mark Rivers -# August 12, 2000 -# -# Note: This database is completely general for the MM4005, it makes no -# assumptions about the motors defined on particular axis. Thus it can be used -# with the Newport diffractometer or any other set of up to 8 motors. -# -# Macro paramters: -# $(P) - PV name prefix -# $(R) - PV base record name -# $(NAXES) - Number of axes to be used. Typically 6 for diffractometer. -# $(NELM) - Maximum number of trajectory elements -# $(NPULSE) - Maximum number of output pulses -# $(DONPV) - Name of PV to turn detector on -# $(DONV) - Value to write to DONPV to turn detector on -# $(DOFFPV) - Name of PV to turn detector off -# $(DOFFV) - Value to write to DOFFPV to turn detector off -# $(C) - Card # (0,1,2...) of the board with the IP slot for the -# generic serial records -# $(IPSLOT) - IP slot (A-D) for the serial I/O module -# $(CHAN) - Channel (0-7) for the serial port -# $(BAUD) - Baud rate for the serial port -# Note: the MM4005 is assumed to be configured with 8 data bits, -# 1 stop bit, no parity. +
++ Loading the database
++The database file is called
trajectoryScan.db.. +This database is completely general for the MM4005 and XPS, it makes no +assumptions about the motors defined on particular axis. Thus it can be used +with the Newport diffractometer or any other set of up to 8 motors. +It takes the following macro parameters: ++ +
+ ++ Macro parameter +Description ++ +$(P)PV name prefix + $(R)PV base record name ++ $(NAXES)Number of axes to be used. 6 for our Newport diffractometers. ++ $(NELM)Maximum trajectory elements ++ $(NPULSE)Maximum number of output pulses ++ $(DONPV)Name of PV to turn detector(s) on ++ $(DONV)Value to write to PV to turn detector on ++ $(DOFFPV)Name of PV to turn detector(s) off ++ +$(DOFFV)Value to write to PV to turn detector off +
++ Starting the SNL program
++There are different SNL programs for the MM4005 and the XPS. The MM4005 SNL program +is defined as follows: +
+program MM4005_trajectoryScan("P=13IDC:,R=traj1,M1=M1,M2=M2,M3=M3,M4=M4,M5=M5,M6=M6,M7=M7,M8=M8,PORT=serial1")-The following is an example of the lines which must be put in the vxWorks -startup file to load
trajectoryScan.db.Note that the command line -is longer than the vxWorks limit, so the command must be built using -malloc,strcpyandstrcat.# Database for trajectory scanning with the MM4005/GPD -# The required command string is longer than the vxWorks -# command line, must use malloc and strcpy, strcat +The parameters are defined as follows: +
+ +
+ ++ Macro parameter +Description ++ +PPV name prefix + RPV base record name ++ M1-M8EPICS motor record names for axes 1-8. ++ +PORTasyn port name for the RS-232 or GPIB port connected to the MM4005 ++The XPS SNL program is defined as follows: +
+program XPS_trajectoryScan("P=13BMC:,R=traj1,IPADDR=164.54.160.34,PORT=5001," + "USERNAME=Administrator,PASSWORD=Administrator," + "M1=m1,M2=m2,M3=m3,M4=m4,M5=m5,M6=m6,M7=m7,M8=m8," + "GROUP=g1," + "P1=p1,P2=p2,P3=p3,P4=p4,P5=p5,P6=p6,P7=p7,P8=p8") + ++The parameters are defined as follows: ++ +
+ ++ Macro parameter +Description ++ +PPV name prefix + RPV base record name ++ IPADDRIP address of the XPS. Can be an IP name if the IOC supports DNS. ++ PORTIP port number that XPS uses for socket connections ++ USERNAMEThe user name to use to login to XPS for FTP ++ PASSWORDThe password for the USERNAME account for FTP ++ M1-M8EPICS motor record names for axes 1-8. ++ GROUPThe name of the MultiAxes group for the motors to be moved ++ +P1-P8XPS positioner names for axes 1-8 in this GROUP +
++ Startup script
++The following is an example of the lines from a startup script on a Linux system +to load
trajectoryScan.dband start the sequencer for an XPS system. +Note that thedbLoadRecordsandseqcommands are shown on multiple +lines here for clarity, but they must each actually be on a single long line. ++# Database for trajectory scanning with the XPS + +dbLoadRecords("$(MOTOR)/motorApp/Db/trajectoryScan.db", + "P=13BMC:,R=traj1,NAXES=6,NELM=2000,NPULSE=2000,PORT=5001, + DONPV=13BMC:str:EraseStart,DONV=1,DOFFPV=13BMC:str:StopAll,DOFFV=1") + +iocInit + +dbpf("13BMC:traj1DebugLevel","1") + +seq(XPS_trajectoryScan, "P=13BMC:,R=traj1,M1=m33,M2=m34,M3=m35,M4=m36,M5=m37,M6=m38, + IPADDR=164.54.160.124,PORT=5001,GROUP=GROUP1, + P1=PHI,P2=KAPPA,P3=OMEGA,P4=PSI,P5=2THETA,P6=NU") ++ ++The following is an example of the lines from a startup script on a vxWorks system +to load
+ +trajectoryScan.dband start the sequencer for a vxWorks system. ++# Database for trajectory scanning with the MM4005 +# The required command string is longer than the vxWorks command line, must use malloc and strcpy, strcat str = malloc(300) -strcpy(str,"P=13IDC:,R=traj1,NAXES=6,NELM=1000,NPULSE=1000,C=0,IPSLOT=a,CHAN=2,BAUD=19200") -strcat(str,",DONPV=13IDC:str:EraseStart,DONV=1,DOFFPV=13IDC:str:StopAll,DOFFV=1") -strcat(str,",M1=Phi,M2=Kappa,M3=Omega,M4=Psi,M5=2-Theta,M6=Nu,M7=Unused,M8=Unused") -dbLoadRecords("CARSApp/Db/trajectoryScan.db", str) +strcpy(str, "P=13IDC:,R=traj1,NAXES=6,NELM=2000,NPULSE=2000,") +strcat(str, "DONPV=13IDC:str:EraseStart,DONV=1,DOFFPV=13IDC:str:StopAll,DOFFV=1") +dbLoadRecords("$(CARS)/CARSApp/Db/trajectoryScan.db", str) + +iocInit + +# Trajectory scanning with MM4005 +seq(&MM4005_trajectoryScan, "P=13IDC:, R=traj1, M1=m25,M2=m26,M3=m27,M4=m28,M5=m29,M6=m30,M7=m31,M8=m32,PORT=serial13") +-DONPVandDOFFPVin this example are for the + +
-DONPVandDOFFPVin these examples are for the Struck/SIS multichannel scaler database (Struck8.db). For this database writing a 1 toEraseStartclears and starts the multichannel scaler, writing 1 toStopAllstops it. The names -M1 ... M8are used to define theMnNamerecords, which -in turn provide the motor labels on the MEDM displays.After
iocInitis called in the startup script the SNL program -must be started. Here is an example:seq &trajectoryScan, "P=13IDC:, R=traj1"
+M1 ... M8are used to define the EPICS motors records for the 8 motors in the controller. +
-
-MEDM screens
-The following show the MEDM screens with which the user can view and modify +
+ MEDM screens
++The following show the MEDM screens with which the user can view and modify the trajectory scanning parameters.
trajectoryScan.adlis the main screen used to define, build, -execute and read back trajectories. The only thing which cannot be done in MEDM +execute and read back trajectories. The only thing that cannot be done in MEDM is to edit theMnTrajandTimeTrajarrays, since MEDM -does not provide a method to edit arrays.trajectoryScan.adlis +does not provide a method to edit arrays. + ++
-trajectoryScan.adlis called with macro parametersP, R, TITLE, and M1 ... M8. PandRare the prefix and record base used when the database was loaded. -M1 ... M8are the names of the motors. These are used to label the -plots intrajectoryPlot.adl. For example +M1 ... M8are the names of the EPICS motors. These are used to label the +plots intrajectoryPlot.adlusing the .DESC fields of the motors. For exampletrajectoryScan.adlin this screen shot was called with -P=13IDC:, R=traj1, TITLE=GPD_Trajectory_Scan, M1=Phi, M2=Kappa, M3=Omega, -M4=Psi, M5=2-Theta, M6=Nu, M7=Unused, M8=Unused.
-
trajectoryPlot.adlis used to plot the requested trajectory in ++P=13BMC:, R=traj1, TITLE=Trajectory Scans, M1=m33,M2=m34,M3=m35,M4=m36,M5=m37,M6=m38,M7=m25,M8=m26 +. + ++
+ ++
-trajectoryPlot.adlis used to plot the requested trajectory in position and time (MnTraj,TimeTraj), the readback positions (MnActual) and the following errors (MnError).
-
trajectoryScanDebug.adlis used to display detailed information, + ++
+ ++
-trajectoryScanDebug.adlis used to display detailed information, useful for debugging.
+ +
+
+
-
-Example IDL Procedure
-The following IDL function illustrates how an EPICS channel access client can -define, build, execute and read back a trajectory.
function trajectory_demo1, build=build, execute=execute, read=read, $ - actual, error, counts +
+ Example IDL Procedure
++The following IDL function illustrates how an EPICS channel access client can +define, build, execute and read back a trajectory.
++function trajectory_scan, traj, positions, relative=relative, hybrid=hybrid, $ + time=time, accel=accel, npulses=npulses, $ + build=build, execute=execute, read=read, $ + actual=actual, errors=errors ;+ ; NAME: -; trajectory_demo1 +; trajectory_scan ; ; PURPOSE: -; This IDL function demonstates how a channel access client can -; define, build, execute and read back a complex trajectory with the -; MM4005. +; This IDL function loads and execute a complex trajectory +; using the EPICS trajectory scan databases and SNL programs. The EPICS +; support current exists for the Newport MM4005 and XPS motor controllers. ; -; The trajectory parameters are as follows: -; 101 elements, 300 output pulses, 30 second execution time, 1 second -; acceleration time. -; -; Only the Phi and Kappa axes are moved. -; -; The Phi trajectory is a sin wave with two complete periods and an -; amplitude of +-8 degrees. -; -; The Kappa trajectory is a sin wave with one complete period and an -; amplitude of +-20 degrees. -; -; The readback includes the Phi, Kappa and Omega actual positions and -; following errors. Omega is interesting because although it was not -; moved during the trajectory it has some following error because of -; the moving mass of the Kappa arm. -; -; The function returns counts from an SIS multichannel scaler which is -; triggered by the output pulses. ; ; CATEGORY: -; EPICS trajectory scanning +; EPICS trajectory scanning ; ; CALLING SEQUENCE: -; Result = TRAJECTORY_DEMO1(Actual, Error, Counts) +; Result = TRAJECTORY_SCAN(Trajectory, Positions) ; ; INPUTS: -; None. +; TRAJ: The EPICS record name for this trajectory, for example '13BMC:traj1'. +; +; POSITIONS: [NELEMENTS, NMOTORS]. The positions of the motors at each element in the trajectory. +; By default the positions are absolute motor positions. If the RELATIVE +; keyword is present then the positions are deltas, i.e. the difference in position +; from the previous point. +; ; ; KEYWORD PARAMETERS: -; BUILD: Set this keyword to build the trajecotry +; RELATIVE: Set this keyword if the positions are deltas, i.e. the difference in position +; from the previous point. Default mode=ABSOLUTE. +; HYBRID: Set this keyword if the trajectory should be executed in "Hybrid" mode, i.e. +; the positions are absolute rather than deltas, but the trajectory should be +; executed from the current motor positions without moving to the first point +; in the postions array. Default mode=ABSOLUTE. +; TIME: If this keyword is a scaler, then it specifies the total time to execute +; the trajectory. If it is an array then it specifies the time per element. +; Default=1 second per element. +; ACCEL: The acceleration time for the trajectory. Only for the MM4005. Default=1 second. +; NPULSES: The number of output pulses during the trajectory. Default=NELEMENTS, the number +; of points in the input Positions array. +; BUILD: Set this keyword to build and verify the trajectory. This is the default. ; -; EXECUTE: Set this keyword to execute the trajectory +; EXECUTE: Set this keyword to execute the trajectory. This is the default. ; -; READ: Set this keyword to read back the trajectory into -; Actual and Error +; READ: Set this keyword to read back the trajectory into ACTUAL and ERROR. +; The default is to not read back. ; -; NOTE: Any or all of these keywords can be set. If none is set then the -; function does not do anything. +; NOTE: Any or all of these keywords can be set. If none is set then the +; function does not do anything. ; ; OUTPUTS: ; Result: This function returns a status indicating whether the ; selected operations were successful or not. 0=success, ; anything else is a failure. -; Actual: An array of [Nactual, 3] containing the actual positions of -; the Phi, Kappa and Omega axes. -; Error: An array of [Nactual, 3] containing the following errors of -; the Phi, Kappa and Omega axes. -; Counts: An array of [Nactual, 4] containing the counts from the -; SIS 3801 multi-channel scaler. The EPICS_MED class library -; is used to communicate with this device. -; -; NOTE: The Actual, Error and Counts outputs are only returned if the -; READ keyword it set. +; ACTUAL: An array of [Nactual, NMOTORS] containing the actual positions of +; each axis. +; ERRORS: An array of [Nactual, NMOTORS] containing the following errors of +; each axis. +; NOTE: The ACTUAL and ERROR outputs are only returned if the READ keyword it set. ; ; SIDE EFFECTS: -; This procedure can move the diffractometer. Be careful! +; This procedure can move the motors. Be careful! ; ; EXAMPLE: -; status = trajectory_demo1(/build) -; status = trajectory_demo1(/execute) -; status = trajectory_demo1(/read, actual, error, counts) +; positions = [[1,2,3],[.1, .2, .3], [0,3,4]] +; status = TRAJECTORY_SCAN('13IDC:traj1', positions, /read, actual, errors) ; plot, actual[*,0] -; plot, error[*,0] -; plot, counts[*,0] +; oplot, errors[*,0] ; ; MODIFICATION HISTORY: -; Written by: Mark Rivers, August 13, 2000 +; Written by: Mark Rivers, December 15, 2006 ;- - prefix = '13IDC:' - traj = prefix + 'traj1' - phi = traj + 'M1' - kappa = traj+'M2' - omega = traj+'M3' - mcs = prefix + 'str:' + t = caget(traj+'NumAxes', maxAxes) - ; Make sure the MCS is in External channel advance mode - t = caput(mcs+'ChannelAdvance', 'External') + MoveMode = 'Absolute' + if (keyword_set(relative)) then MoveMode = 'Relative' + if (keyword_set(hybrid)) then MoveMode = 'Hybrid' + t = caput(traj+'MoveMode', MoveMode) + + if (n_elements(build) eq 0) then build=1 + if (n_elements(execute) eq 0) then execute=1 if (keyword_set(build)) then begin - ; The trajectory definition is hybid mode, meaning the positions are - ; definined in absolute coordinates rather than displacements from on - ; element to the next. However, the motors do not move to the absolute - ; position of the first element before executing the trajectory. - MoveMode = 'Hybrid' - t = caput(traj+'MoveMode', MoveMode) + dims = size(positions, /dimensions) + nelements = dims[0] + naxes = dims[1] + if (n_elements(npulses) eq 0) then npulses = nelements - ; 101 elements in the trajectory. We use 4N+1 since we are defining the - ; trajectory in Hybrid mode - nelements = 101 t = caput(traj+'Nelements', nelements) - ; 300 output pulses during the trajectory - npulses = 300 t = caput(traj+'Npulses', npulses) - ; 30 seconds total time to execute the trajectory - t = caput(traj+'TimeMode', 'Total') - time = 30. - t = caput(traj+'Time', time) + ; Default is 1 second per element + if (n_elements(time) eq 0) then time = nelements * 1.0 + if (n_elements(time) eq 1) then begin + t = caput(traj+'TimeMode', 'Total') + t = caput(traj+'Time', time) + endif else begin + t = caput(traj+'TimeMode', 'Per element') + t = caput(traj+'TimeTraj', time) + endelse - ; 1 second acceleration time - accel = 1. + if (n_elements(accel) eq 0) then accel = 1. t = caput(traj+'Accel', accel) - ; The Phi and Kappa motors will move. - t = caput(phi+'Move', 1) - t = caput(kappa+'Move', 1) - - ; The Phi trajectory is a sin wave with two complete periods and an - ; amplitude of +-8 degrees - phiTraj = 8.*sin(findgen(nelements)/(nelements-1.)*4.*!pi) - t = caput(phi+'Traj', phiTraj) - - ; The Kappa trajectory is a sin wave with one complete period and an - ; amplitude of +-20 degrees - kappaTraj = 20.*sin(findgen(nelements)/(nelements-1.)*2.*!pi) - t = caput(kappa+'Traj', kappaTraj) + ; The first naxes motors will move. + for i=0, maxAxes-1 do begin + axis = traj + 'M' + strtrim(i+1,2) + if (i lt naxes) then begin + t = caput(axis+'Move', 1) + pos = positions[*,i] + t = caput(axis+'Traj', pos) + endif else begin + t = caput(axis+'Move', 0) + endelse + endfor ; Trajectory is now defined. Build it. t = caput(traj+'Build', 1) ; Wait for the build to complete. Wait 0.1 second between polls. repeat begin wait, 0.1 - t = caget(traj+'Build', Build) - endrep until (Build eq 0) + t = caget(traj+'Build', busy) + endrep until (busy eq 0) ; Make sure the build was successful t = caget(traj+'BuildStatus', BuildStatus, /string) @@ -945,8 +1165,8 @@ define, build, execute and read back a trajectory.function trajectory_d ; Wait for the execute to complete. Wait 0.1 second between polls. repeat begin wait, 0.1 - t = caget(traj+'Execute', Execute) - endrep until (Execute eq 0) + t = caget(traj+'Execute', busy) + endrep until (busy eq 0) ; Make sure the execution was successful t = caget(traj+'ExecStatus', ExecStatus, /string) @@ -962,8 +1182,8 @@ define, build, execute and read back a trajectory.function trajectory_d ; Wait for the readback to complete. Wait 0.1 second between polls. repeat begin wait, 0.1 - t = caget(traj+'Readback', Readback) - endrep until (Readback eq 0) + t = caget(traj+'Readback', busy) + endrep until (busy eq 0) ; Make sure the readback was successful t = caget(traj+'ReadStatus', ReadStatus, /string) @@ -973,33 +1193,94 @@ define, build, execute and read back a trajectory.+The improvement in performance is dramatic. Using step scanning the overhead per point is about 1 second, so a 500 point scan takes a minimum of 500 seconds or more than 8 minutes. Using trajectory scanning the total time to execute a 500 point scan with .002 seconds per point is 3 seconds, including the time to print and plot the data and write it to the data file. -function trajectory_d return, ReadStatus endif - ; Read the Phi and Kappa actual and error arrays into IDL, return to + ; Read the actual and error arrays into IDL, return to ; caller t = caget(traj+'Nactual', nactual) - t = caget(Phi+'Actual', PhiActual, max=nactual) - t = caget(Phi+'Error', PhiError, max=nactual) - t = caget(Kappa+'Actual', KappaActual, max=nactual) - t = caget(Kappa+'Error', KappaError, max=nactual) - t = caget(Omega+'Actual', OmegaActual, max=nactual) - t = caget(Omega+'Error', OmegaError, max=nactual) - actual = [[PhiActual], [KappaActual], [OmegaActual]] - error = [[PhiError], [KappaError], [OmegaError]] - - ; Read the counts from the SIS multichannel scaler - med = obj_new('EPICS_MED', mcs, 4) - counts = med->get_data() - counts = counts[0:nactual-1,*] + actual = dblarr(nactual, maxAxes) + errors = dblarr(nactual, maxAxes) + for i=0, maxAxes-1 do begin + axis = traj + 'M' + strtrim(i+1,2) + t = caget(axis+'Actual', temp, max=nactual) + actual[0,i] = temp + t = caget(axis+'Error', temp, max=nactual) + errors[0,i] = temp + endfor endif return, 0 end -
-SPEC Interface
-A set of SPEC macros allows SPEC to utilize trajectory scanning with EPICS -and the MM4005. -
The implementation is done at a low level, so that all of SPEC's standard -scans can be done "on-the-fly" utilizing this trajectory scanning software. This -was done by providing replacement macros for:
_ascan # Used by all ascan and dscan macros +
++This is an IDL main program that defines a trajectory and executes it using trajectory_scan.pro above. +
+; This program builds a trajectory and executes it. + +; The trajectory definition is hybid mode, meaning the positions are +; definined in absolute coordinates rather than displacements from on +; element to the next. However, the motors do not move to the absolute +; position of the first element before executing the trajectory. + +; 101 elements in the trajectory. We use 4N+1 since we are defining the +; trajectory in Hybrid mode + nelements = 101 + +; We will move the first 2 motors (Phi and Kappa) + naxes=2 + +; Define array of positions +positions = dblarr(nelements, naxes) + +; The Phi trajectory is a sin wave with two complete periods and an +; amplitude of +-8 degrees +positions[*,0] = 8.*sin(findgen(nelements)/(nelements-1.)*4.*!pi) + +; The Kappa trajectory is a sin wave with one complete period and an +; amplitude of +-20 degrees +positions[*,1] = 20.*sin(findgen(nelements)/(nelements-1.)*2.*!pi) + +trajectory = '13BMC:traj1' + +; Total time for trajectory +time = 20. + +status = trajectory_scan(trajectory, positions, /hybrid, /build, /execute, /read, $ + time=time, npulses=300, actual=actual, errors=errors) + +end +
+ ++These are the IDL commands to execute the above program, and plot the results: +
+IDL> .run trajectory_test1 +IDL> iplot, actual[*,0] +IDL> iplot, actual[*,1], /overplot +IDL> iplot, errors[*,0] +IDL> iplot, errors[*,1], /overplot +
++These are the resulting plots: +
+
+ +
+
+ + +
++ SPEC Interface
++A set of SPEC macros allows SPEC to utilize trajectory scanning with EPICS +and the MM4005 or XPS. It requires a multi-channel scaler or some other +detector that can be triggered and has buffering. +
+The implementation is done at a low level, so that all of SPEC's standard +scans can be done "on-the-fly" utilizing this trajectory scanning software. +This +was done by providing replacement macros for: +
+_ascan # Used by all ascan and dscan macros mesh hklscan # Used by hscan, kscan and lscan _hklmesh @@ -1007,23 +1288,30 @@ _hklline # Used by hkcircle, hlcircle, klcircle, hkradial, hlradial and klradia _scanabort resume _loop -
It adds the following new macros:traj_index # Converts a SPEC motor index to an MM4005 motor index +
+It adds the following new macros: ++traj_index # Converts a SPEC motor index to an MM4005 or XPS motor index traj_build # Builds a trajectory traj_exec # Executes a trajectory traj_read_counts # Reads the data from the multi-channel scaler -traj_read_actual # Reads back the actual MM4005 motor positions +traj_read_actual # Reads back the actual MM4005 or XPS motor positions traj_scans_on # Enables trajectory scanning traj_scans_off # Disables trajectory scanning, uses step scanning -
The improvement in performance is dramatic. Using step scanning the +It is easy to switch back and forth between traditional step scanning and -trajectory scanning.
traj_scans_onturns on trajectory scanning for ++It is easy to switch back and forth between traditional step scanning and +trajectory scanning. +
traj_scans_onturns on trajectory scanning for all subsequent scans.traj_scans_offreverts back to traditional step scanning. -It is possible to have the motor positions and HKL values which SPEC prints +
+It is possible to have the motor positions and HKL values that SPEC prints on the screen, plots and stores in the SPEC data file be based upon the theoretical motor positions during the scan. Alternatively SPEC can use values based upon the actual motor positions at each point in the scan. @@ -1031,4 +1319,15 @@ Using the actual motor positions is slower, because the values must be read from the MM4005 at the end of the trajectory execution. Set the SPEC global variable
TRAC_USE_ACTUAL=0to use the theoretical motor positions, andTRAJ_USE_ACTUAL=1to use the actual motor positions. -