@@ -118,10 +100,9 @@ The goals of this module are:
Architecture
-The architecture of the areaDetector module is shown in Figure 1. +The architecture of the areaDetector module is shown below. -
Figure 1. Architecture of areaDetector module.
-
-
@@ -129,19 +110,19 @@ From the bottom to the top this architecture consists of the following:
communicate with the hardware.
It is usually provided by the detector vendor. It may consist of a library or DLL,
of a socket protocol to a driver, a Microsoft COM interface, etc.
-
- Layer 2. This is the driver that is written for the area detector application to +
- Layer 2. This is the driver that is written for the areaDetector application to control a particular detector. It is normally written in C++ and inherits from the ADDriver class. It uses the standard asyn interfaces for control and status information. Each time it receives a new data array it passes it as an NDArray object to all Layer 3 clients that have registered for callbacks. This is the only code that needs to be written to implement a new detector. Existing drivers range from - 650 to 950 lines of code. + 650 to 1050 lines of code.
- Layer 3. Code running at this level is called a "plug-in". This code registers with a driver for a callback whenever there is a new data array. The existing plugins implement file saving (NDPluginFile), region-of-interest (ROI) calculations (NDPluginROI), and conversion of detector data to standard EPICS array types for use by Channel Access clients (NDPluginStdArrays). Plugins are normally written in C++ and - inherit from NDPluginDriver. Existing plugins range from 280 to 550 lines + inherit from NDPluginDriver. Existing plugins range from 280 to 650 lines of code.
- Layer 4. This is standard asyn device support that comes with the EPICS asyn module.
- Layer 5. These are standard EPICS records, and EPICS database (template) files that
@@ -155,16 +136,21 @@ From the bottom to the top this architecture consists of the following:
The code in Layers 1-3 is essentially independent of EPICS. There are only 2 EPICS dependencies in this
code.
-
-
- libCom. libCom from EPICS base provides operating-system independent functions for +
- libCom. + libCom from EPICS base provides operating-system independent functions for threads, mutexes, etc. -
- asyn. asyn is a module that provides interthread messaging services, including queueing +
- asyn. + asyn is a module that provides interthread messaging services, including queueing and callbacks.
-The plugin architecture is very powerful, because plugins can be reconfigured at run-time. For example +The plugin architecture is very powerful, because new plugins can be written for application-specific +purposes. For example, a plugin could be written to analyze images and find the center of the beam, +and such a plugin would then work with any detector driver. +Plugins are also powerful because they can be reconfigured at run-time. For example the NDPluginStdArrays can switch from getting its array data from a detector driver to an NDPluginROI plugin. That way it will switch from displaying the entire detector to whatever sub-region the ROI driver has selected. Any Channel Access clients connected to the NDPluginStdArrays driver @@ -172,8 +158,8 @@ will automatically switch to displaying this subregion. Similarly, the NDPluginFile plugin can be switched at run-time from saving the entire image to saving a selected ROI, just by changing its input source.
-The use of plugins is optional, and it is only plugins that require the driver to make the -image data available. If there are no plugins being used then EPICS can be used simply +The use of plugins is optional, and it is only plugins that require the driver to make callbacks with +image data. If there are no plugins being used then EPICS can be used simply to control the detector, without accessing the data itself. This is most useful when the vendor API has the ability to save the data to a file.
@@ -186,11 +172,14 @@ it should be easy to build applications that do not run as part of an EPICS IOC.
asynPortDriver
Drivers and plugins each need to support a number of parameters that control their operation and provide @@ -561,8 +550,9 @@ The methods of the NDArray class are: binning=1, reverse=0, offset=0.
getInfo. This convenience method returns information about an NDArray, including the total number of elements, the number of byte per element, and the total number of bytes in the array. -copy. This method makes a copy of an NDArray object. The output array object must already exist - and must have sufficient memory allocated to it to hold the data. +copy. This method makes a copy of an NDArray object. If the output array pointer is NULL + then it is first allocated. If the output array object already exists (pOut!=NULL) then it + must have sufficient memory allocated to it to hold the data.reserve. This method calls NDArrayPool->reserve() for this object. It increases the reference count for this array.release. This method calls NDArrayPool->release() for this object. It decreases the reference @@ -598,7 +588,7 @@ public: The methods of the NDArrayPool class are:NDArrayPoolThis is the constructor for the class. The maxBuffers argument is the maximum - number of NDArray objects that the pool is allowed to contain. The maxmMemory argument is the maxiumum + number of NDArray objects that the pool is allowed to contain. The maxMemory argument is the maxiumum number of bytes of memory the the pool is allowed to use, summed over all of the NDArray objects.allocThis method allocates a new NDArray object. The first 3 arguments are required. ndims is the number of dimensions in the NDArray. dims is an array of dimensions, whose size must be at least ndims. @@ -693,1018 +683,534 @@ The methods of the ADDriver class are: ADFilePath, ADFileName, ADFileNumber, and ADFileTemplate parameters.
- simDetector
-class simDetector : public ADDriver { -public: - simDetector(const char *portName, int maxSizeX, int maxSizeY, NDDataType_t dataType, - int maxBuffers, size_t maxMemory); - - /* These are the methods that we override from ADDriver */ - virtual asynStatus writeInt32(asynUser *pasynUser, epicsInt32 value); - virtual asynStatus writeFloat64(asynUser *pasynUser, epicsFloat64 value); - virtual asynStatus drvUserCreate(asynUser *pasynUser, const char *drvInfo, - const char **pptypeName, size_t *psize); - void report(FILE *fp, int details); --The portName, maxBuffers, and maxMemory arguments are passed to the base class constructors. The maxSizeX, maxSizeY, and -dataType arguments are specific to the simulation driver, controlling the maximum image size and initial data type of the -computed images. The writeInt32 and writeFloat64 methods override those in the base class. The driver takes action -when new parameters are passed via those interfaces. For example, the ADAcquire parameter (on the asynInt32 interface) is -used to turn acquisition (i.e. computing new images) on and off. --The simulation driver initially sets the image[i, j] = i*gainX + j*gainY * gain * exposureTime * 1000. Thus the -image is a linear ramp in the X and Y directions, with the gains in each direction being detector-specific parameters. -Each subsquent acquisition increments each pixel value by gain*exposureTime*1000. Thus if gain=1 and exposureTime=.001 -second then the pixels are incremented by 1. If the array is an unsigned 8 or 16 bit integer then the pixels -will overflow and wrap around to 0 after some period of time. This gives the appearance of bands that appear to move -with time. The slope of the bands and their periodicity can be adjusted by changing the gains and exposure times. -
-The driver creates a thread that waits for a signal to start acquisition. When acquisition is started that thread -computes new images and then calls back any registered plugins as follows: -
- /* Put the frame number and time stamp into the buffer */ - pImage->uniqueId = imageCounter; - pImage->timeStamp = startTime.secPastEpoch + startTime.nsec / 1.e9; - - /* Call the NDArray callback */ - /* Must release the lock here, or we can get into a deadlock, because we can - * block on the plugin lock, and the plugin can be calling us */ - epicsMutexUnlock(this->mutexId); - asynPrint(this->pasynUser, ASYN_TRACE_FLOW, - "%s:%s: calling imageData callback\n", driverName, functionName); - doCallbacksGenericPointer(pImage, NDArrayData, addr); - epicsMutexLock(this->mutexId); -
-The 3 driver-specific parameters are defined in the driver as follows: --/* If we have any private driver parameters they begin with ADFirstDriverParam and should end - with ADLastDriverParam, which is used for setting the size of the parameter library table */ -typedef enum { - SimGainX - = ADFirstDriverParam, - SimGainY, - SimResetImage, - ADLastDriverParam -} SimDetParam_t; +-The drvUserCreate function first checks to see if the parameter is one of these -3 parameters that are unique to the simulation driver. If not it checks to -see if it is a standard parameter by calling the ADDriver base class method.+ ADStdDriverParams
ADStdDriverParams.hdefines the following: -#define NUM_SIM_DET_PARAMS (sizeof(SimDetParamString)/sizeof(SimDetParamString[0])) --asynStatus simDetector::drvUserCreate(asynUser *pasynUser, - const char *drvInfo, - const char **pptypeName, size_t *psize) +/* Enumeration of shutter status */ +typedef enum { - asynStatus status; - int param; - const char *functionName = "drvUserCreate"; + ADShutterClosed, + ADShutterOpen +} ADShutterStatus_t; + +/* Enumeration of detector status */ +typedef enum +{ + ADStatusIdle, + ADStatusAcquire, + ADStatusReadout, + ASStatusCorrect, + ADStatusSaving, + ADStatusAborting, + ADStatusError, +} ADStatus_t; + +typedef enum +{ + ADImageSingle, + ADImageMultiple, + ADImageContinuous +} ADImageMode_t; + +typedef enum +{ + ADTriggerInternal, + ADTriggerExternal +} ADTriggerMode_t; - /* See if this is one of our standard parameters */ - status = findParam(SimDetParamString, NUM_SIM_DET_PARAMS, - drvInfo, ¶m); - - if (status == asynSuccess) { - pasynUser->reason = param; - if (pptypeName) { - *pptypeName = epicsStrDup(drvInfo); - } - if (psize) { - *psize = sizeof(param); - } - asynPrint(pasynUser, ASYN_TRACE_FLOW, - "%s:%s: drvInfo=%s, param=%d\n", - driverName, functionName, drvInfo, param); - return(asynSuccess); - } - - /* If not, then see if it is a base class parameter */ - status = ADDriver::drvUserCreate(pasynUser, drvInfo, pptypeName, psize); - return(status); -}- -- Prosilica Driver
- EPICS records
-
+
- Enum name: The name of the enum value for this parameter in ADStdDriverParams.h. There are several EPICS + records in ADBase.template that do not have corresponding enum fields, + and these are indicated as Not Applicable (N/A). +
- asyn interface: The asyn interface used to pass this parameter to the driver. +
- Access: Read-write (r/w) or read-only (r/o). +
- drvUser string: The string used to look up the parameter in the driver through the drvUser interface. + This string is used in the EPICS database file for generic asyn device support to associate a record with + a particular parameter. +
- EPICS record name: The name of the record in ADBase.template. Each record name begins with the two macro + parameters $(P) and $(R). In the case of read/write parameters there are normally two records, one for writing + the value, and a second, ending in _RBV, that contains the actual value (Read Back Value) of the parameter. +
- EPICS record type: The record type of the record. Waveform records are used to hold long strings, + with length (NELM) = 256 bytes and EPICS data type (FTVL) = UCHAR. +
-The following EPICS records are used by pilatusROI. All records are prefixed by the macro -$(DET) which must be passed to the template file when the records are loaded.
-- Acquisition related records
--
-
AcquireMode(mbbo)
- This record controls the acquisition mode. The allowed values are: --
-
- 0 ("Internal") Internal exposure mode, external signal not used. -
- 1 ("Ext. Enable") External enable mode. External signal controls acquire and readout. -
- 2 ("Ext. Trigger") External trigger mode. External signal triggers an acquisition sequence. -
- 3 ("Mult. Trigger") Multiple trigger mode. Each external trigger edge triggers a single acquisition - for the programmed exposure time. -
- 4 ("Alignment") Alignment mode. Repetitively collects single images as quickly as possible.
- The images are written to a temporary file.
- The
MinImageUpdateTimePV is ignorred in - this mode, so that all images are sent to EPICS for display. - It is similar to theexposemcommand in TVX. -
Exposure, -ExtEnable,ExtTrigger, andExtMTriggerrespectively. - Alignment mode uses theExposurecommand as well, but continuously takes images into - the same temporary file (alignment.tif). -ExposureTime(ao)
- This record controls the exposure time in seconds. In External Enable mode this value is not - used by camserver. However, it should be set larger than the maximum time exposure time from the - external source, so that pilatusROI.st can estimate how long - to wait for the data files to be created before timing out. -NImages(longout)
- This record controls the number of images to acquire. It applies in all acquisition modes except - Alignment. -ExposurePeriod(ao)
- This record controls the exposure period in seconds. It is only in Internal or External Trigger modes - when NImages>1. -NExposures (longout)
- This record controls the number of exposures per image. It is only used in External Enable mode. -DelayTime(ao)
- This record controls the delay in seconds between the external trigger - and the start of image acquisition. It only applies in External Trigger mode. -Acquire(busy)
- This record controls the acquisition. Setting this record to 1 ("Busy") starts image acquisition. - The SNL program sets the record to 0 ("Done") when acquisition is complete. This means an entire - acquisition series if NImages>1. This record is an EPICS - "busy" record from the synApps sscan module. This record does not call recGblFwdLink until - acquisition is complete. It can thus be used with the sscan record as a detector trigger that - will wait for acquisition to complete before going to the next point in the scan. It can also - be used with EPICS caPutCallback to wait for acquisition to complete before the callback completes. -Armed(bo)
- This record signals when the Pilatus is ready to accept trigger pulses. It changes from 0 to 1 - after camserver sends a response to an acquire start command indicating that the Pilatus is ready to - begin taking data. The SNL program sets the record to 0 when acquisition is complete. - This PV should be used by clients to indicate when it is OK to start sending trigger pulses - to the Pilatus. If pulses are send before Armed=1 then the Pilatus may miss them, leading to - DMA timeout errors from camserver. -Abort(bo)
- This record aborts an acquisition. Setting this record to 1 stops whatever acquisition is in progress. - If pilatusROI - was currently acquiring imges (Acquire=Busy) then this record will cause the "K" (Kill) command to - be sent to camserver. It will also set Acquire back to Done. -StatusMessage(stringout)
- This record contains a string that provides status information on the state of pilatusROI. It contains - strings like "Starting exposure", "Waiting for TIFF file", etc. -
-
- Detector related records
--
-
ThresholdEnergy(ao)
- This record controls the threshold energy in eV. -Gain(mbbo)
- This record controls the value of Vrf, which in determines the shaping time and gain of the - input amplifiers. The allowed values are: --
-
- 0 ("Fast/Low") Fastest shaping time (~125ns) and lowest gain. -
- 1 ("Medium/Medium") Medium shaping time (~200 ns) and medium gain. -
- 2 ("Slow/High") Slow shaping time (~400 ns) and high gain. -
- 3 ("Slow/Ultrahigh") Slowest peaking time (? ns) and highest gain. -
-
- File name related records
-The FilePath, Filename, FileNumber, and FileFormat PVs are all used to create the final FullFilename. --
-
FilePath(waveform, FTVL=UCHAR, NELM=256)
- This record controls the path for saving images. It must be a valid path for camserver - and for the SNL program. - If camserver and the EPICS IOC are not running on the same machine then soft links - will typically be used to make the paths look identical.- This record is an EPICS waveform record with FTVL=UCHAR and NELM=256. - This removes the 40 character - restriction on path name lengths that arise if an EPICS "string" PV is used. medm allows one to - edit and display such records correctly. EPICS clients will typically need to convert the path - name from a string to an integer or byte array before sending the path name to EPICS. This is easy - to do in clients like SPEC, Matlab, and IDL. -
Filename(stringout)
- This record controls the base file name for saving images. It is limited to 40 characters. -FileNumber(longout)
- This record controls the number of the next file for saving images. -FileFormat(stringout)
- This record controls how the FilePath, Filename, and FileNumber are combined to form the final - file name. The format string is limited to 40 characters. - The final file name (which can be up to 256 characters) is created with the following code: -- epicsSnprintf(FullFilename, sizeof(FullFilename), FileFormat, - FilePath, Filename, FileNumber); -
- FilePath, Filename, FileNumber are converted in that order with FileFormat. - The default file format is"%s%s%4.4d.tif". The first %s converts the FilePath, - followed immediately by another %s for Filename. - FileNumber is formatted with %4.4d, which results in a - fixed field with of 4 digits, with leading zeros as required. Finally, the .tif extension - is added to the file name. This will make camserver save files in TIFF format with that extension. -- This mechanism for creating file names is very flexible. Other characters, such as _ can be put - in Filename or FileFormat as desired. If one does not want to have FileNumber in the file name - at all, then just omit the %d format specifier from FileFormat. -
- Note that when saving multiple images (NImages>1) camserver has its own rules for creating the - names of the individual files. The rules are as follows: -
- The name constructed using the above algorithm is used as a basename. - The following examples show the interpretation of the basename. -
- Basename Files produced - - test6.tif test6_00000.tif, test6_00001.tif, ... - test6_.tif test6_00000.tif, test6_00001.tif, ... - test6_000.tif test6_000.tif, test6_001.tif, ... - test6_014.tif test6_014.tif, test6_015.tif, ... - test6_0008.tif test6_0008.tif, test6_0009.tif, ... - test6_2_0035.tif test6_2_0035.tif, test6_2_0036.tif, ... -
- - The numbers following the last '_' are taken as a format template, - and as a start value. The minimum format is 3; there is no maximum; the - default is 5. The format is also constrained by the requested number of images. -AutoIncrement(bo)
- This record controls whether FileNumber is automatically incremented by 1 each time an acquisition - completes. 0=No, 1=Yes. -FullFilename(waveform, FTVL=UCHAR, NELM=256)
- This is a read-only record that contains the full filename of the current file, after the above - code has been executed. Note that the FullFilename is not constructed until Acquire is set to 1. -
- ROI related records
-The SNL code supports up to 32 rectangular ROIs. Fewer ROIs can be used by loading the pilatusROI_N.template file -fewer than 32 times, and passing NROIS<32 to the SNL program when it is started. In the following -record names $(N) is a number from 1 to 32. ROIs can be any size from a single pixel to the entire -chip. -An ROI is considered invalid and ignorred by the SNL program if any of Xmin, Xmax, YMin, YMax is less than 0 or -greater than the size of the chip in that direction. The ROI is also invalid if Xmin>XMax or YMin>YMax. --
-
ROI$(N)XMin(longout)
- The minimum value of X for ROI N. -ROI$(N)XMax(longout)
- The maximum value of X for ROI N. -ROI$(N)YMin(longout)
- The minimum value of Y for ROI N. -ROI$(N)YMax(longout)
- The maximum value of Y for ROI N. -ROI$(N)BgdWidth(longout)
- The background width ROI N. ROI$(N)BgdWidth<=0 means no background subtraction is done, and - ROI$(N)NetCounts=ROI$(N)TotalCounts. The background region is defined as follows: --
-
- If ROI$(N)BgdWidth=1 then the background is one pixel outside of the perimeter of the ROI, - i.e the single-pixel wide - rectangular box defined by ROI$(N)XMin-1, ROI$(N)XMax+1, ROI$(N)YMin-1, and ROI$(N)YMax+1. - However, if any of those locations would be outside of the chip then that dimension is changed - to be on the perimeter of the ROI. This ensures that - a valid background region can be defined even if the ROI touches the edge of the detector. -
- If ROI$(N)BgdWidth>1 then the background is a rectangular box of width ROI$(N)BgdWidth, moving - out from the ROI location defined above. However, if the background would go - beyond the edge of the detector, then it is clipped to the largest valid width in - that direction. -
ROI$(N)TotalCounts(ao)
- The total counts in ROI N. -ROI$(N)NetCounts(ao)
- The net counts in ROI N, i.e. the total counts minus the background counts. This is determined - by computing the average number of counts per pixel in the background, and subtracting this from - the counts in the ROI. -ROI$(N)MinCounts(longout)
- The minimum counts in any pixel in ROI N. -ROI$(N)MaxCounts(longout)
- The maximum counts in any pixel in ROI N. This can be useful to monitor to make sure that the 20-bit - limit of 1,048,575 is not being approached. -ROI$(N)Label(stringout)
- The string label for ROI N. -ROI$(N)WFTotalCounts(waveform, FTVL=DOUBLE, NELM=$(NCHANS))
- The total counts in ROI N in a waveform record. Valid when NImages>1. -ROI$(N)WFNetCounts(waveform, FTVL=DOUBLE, NELM=$(NCHANS))
- The net counts in ROI N in a waveform record. Valid when NImages>1. -MinWFUpdateTime(ao)
- This record controls the minimum time between posting the ROI$(N)WFTotalCounts and ROI$(N)WFNetCounts - arrays to EPICS. - This should normally be set to a value >0.1 second to reduce the network bandwidth use. The SNL - program always posts the arrays when acquisition completes, so that the final ROI data for the - series is sent to EPICS. -
- Image related records
--
-
ImageData(waveform, FTVL=LONG, NELM=$(NPIXELS))
- The detector image data as an EPICS waveform record. In order for EPICS clients - to receive this data they must be built with EPICS R3.14 (not R3.13), and the environment variable - EPICS_CA_MAX_ARRAY_BYTES on both the EPICS IOC computer and EPICS client computer must be set to a value - at least as large as the image size in bytes, i.e. to 379860 or more. -NXPixels(longout)
- The number of pixels in the X direction on the detector. The SNL program needs to know this value. - EPICS clients can use this value to reformat ImageData from - a 1-D array to a 2-D array. -NYPixels(longout)
- The number of pixels in the Y direction on the detector. The SNL program needs to know this value. - EPICS clients can use this value to reformat ImageData from - a 1-D array to a 2-D array. -HighlightROIs(bo)
- This record controls the whether the SNL program highlights the ROI borders in the image before - sending the images to EPICS. If selected then the pixels on the ROI borders are replaced with the - value of the most intense pixel in the image, so they will always be visible in the display. - 0=No, don't highlight, 1=Yes, highlight. -PostImages(bo)
- This record controls the whether the SNL program sends ImageData to EPICS. - 0=No, don't send, 1=Yes, send. This can be set to 0 to reduce the network bandwidth use. -MinImageUpdateTime(ao)
- This record controls the minimum time between posting ImageData to EPICS. - This should normally be set to a value >0.5 second to reduce the network bandwidth use. This - means that not all images may be sent to EPICS. This value is ignorred when AcquireMode=Alignment. -
- Bad pixel map related records
--
-
BadPixelFile(waveform, FTVL=UCHAR, NELM=256)
- This record contains the name of a file to be used to replace bad pixels. - If this record does not point to a valid bad pixel file then no bad pixel mapping is performed. - See the notes on theFilePath regarding using waveform records for long strings. - The bad pixel map - is used before computing the ROIs and before sending ImageData to EPICS. It does not modify - the data in the files that camserver writes. This is a simple ASCII file with the following - format: -- badX1,badY1 replacementX1,replacementY1 - badX2,badY2 replacementX2,replacementY2 - ... -
- The X and Y coordinates range from 0 to NXPixels-1 and NYPixels-1. Up to 100 bad pixels can be defined. - The bad pixel mapping simply replaces the bad pixels with another pixel's value. - It does not do any averaging. It is felt that this is sufficient for the purpose for which - pilatusROI was written, namely fast on-line viewing of ROIs and ImageData. More sophisticated - algorithms can be used for offline analysis of the image files themselves. - The following is an example bad pixel file for the GSECARS detector: -- 263,3 262,3 - 264,3 266,3 - 263,3 266,3 - 300,85 299,85 - 300,86 299,86 - 471,129 472,129 -
-NBadPixels(longout)
- The number of bad pixels defined in the bad pixel file. - Useful for seeing if the bad pixel file was read correctly. -
- Flat field correction related records
--
-
FlatFieldFile(waveform, FTVL=UCHAR, NELM=256)
- This record contains the name of a file to be used to correct for the flat field. - If this record does not point to a valid flat field file then no flat field correction is performed. - See the notes on theFilePath regarding using waveform records for long strings. - The flat field file is simply a TIFF file collected by the Pilatus that is used to correct for - spatial non-uniformity in the response of the detector. It should be collected with a spatially uniform - intensity on the detector at roughly the same energy as the measurements being corrected. - When the flat field file is read, the average pixel value (averageFlatField) is computed - using all pixels with intensities > MinFlatField. All pixels with intensity < MinFlatField - in the flat field are replaced with averageFlatField. - When images are collected, before the ROIs are computed, and before the images - are sent to EPICS, the following per-pixel correction is applied: -- ImageData[i] = (averageFlatField * ImageData[i])/flatField[i]; -
-MinFlatField(ao)
- The mimimum valid intensity in the flat field. This value must be set > 0 to prevent divide by 0 errors. - If the flat field was collected with some pixels having very low intensity then this value can be used to - replace those pixels with the average response. -FlatFieldValid(bo)
- This record indicates if a valid flat field file has been read. 0=No, 1=Yes. -
- Communication related records
--
-
ReadTiffTimeout(ao)
- This record controls the timeout in seconds between when the SNL program thinks a TIFF file should be ready - to read, and when a timeout will occur. It should be set to several seconds, because there can be delays - for various reasons. One reason is that there is sometimes a delay between when an External Enable - acquisition is started and when the first external pulse occurs. Another is that it can take some time for - camserver processes to finish writing the files. -SendMessage(waveform, FTVL=UCHAR, NELM=256)
- This read-only record contains the most recent message sent from the SNL program to camserver. -ReplyMessage(waveform, FTVL=UCHAR, NELM=256)
- This read-only record contains the most recent reply message from camserver to the SNL program. -Connect(bo)
- Processing this record causes the drvAsynIPPort server to connect to camserver. - This normally happens once in the - startup script, and does not need to be processed again unless Disconnect is processed. -Disconnect(bo)
- Processing this record causes the drvAsynIPPort server to disconnect from camserver. - This can be used to allow another - program, such as TVX, to temporarily take control of camserver, without restarting the EPICS IOC. Use - the Connect record to reconnect the IOC to camserver. -
- Scan related records
--
-
scan1, scan2, scan3, scan4, scanH(sscan)
- The example IOC startup script loads the scan.sb database from the SSCAN module. This loads 5 sscan - records which can be used to perform up to 4-dimensional scans with any EPICS PV as positioners and - detectors. The scan records are very useful with the Pilatus for scanning the ThresholdEnergy PV - and plotting the counts in an ROI that includes the entire detector. This allows setting the energy - threshold to detect the x-rays of interest. - -
- -- EPICS startup script
-pilatusROI.template is loaded with the following macro parameters:
- +Macro parameter +Parameter Definitions in ADStdDriverParams.h and EPICS Record Definitions in ADBase.template ++ Enum name +asyn interface +Access Description +drvUser string +EPICS record name +EPICS record type - $(DET)PV name prefix. This identifies this Pilatus detector from others that may be - running on the same subnet. - +Information about the detector - $(NXPIXELS)The number of pixels in the X (fast index) direction on the detector. This is 487 for the Pilatus 100K. +ADManufacturer +asynOctet +r/o +Detector manufacturer name +MANUFACTURER +$(P)$(R)Manufacturer_RBV +stringin - $(NYPIXELS)The number of pixels in the Y (slow index) direction on the detector. This is 195 for the Pilatus 100K. +ADModel +asynOctet +r/o +Detector model name +MODEL +$(P)$(R)Model_RBV +stringin - $(NPIXELS)The total number of pixels on the detector. This is NXPIXELS*NYPIXELS=94965 for the Pilatus 100K. +ADMaxSizeX +asynInt32 +r/o +Maximum (sensor) size in the X direction +MAX_SIZE_X +$(P)$(R)MaxSizeX_RBV +longin - +$(PORT)The name of the asyn port connected to the Pilatus via a TCP/IP socket. +ADMaxSizeY +asynInt32 +r/o +Maximum (sensor) size in the Y direction +MAX_SIZE_Y +$(P)$(R)MaxSizeY_RBV +longin ++ +Detector readout control including gain, binning, region start and size, reversal ++ +ADGain +asynFloat64 +r/w +Detector gain +GAIN +$(P)$(R)Gain +
$(P)$(R)Gain_RBVao +
ai+ +ADBinX +asynInt32 +r/w +Binning in the X direction +BIN_X +$(P)$(R)BinX +
$(P)$(R)BinX_RBVlongout +
longin+ +ADBinY +asynInt32 +r/w +Binning in the Y direction +BIN_Y +$(P)$(R)BinY +
$(P)$(R)BinY_RBVlongout +
longin+ +ADMinX +asynInt32 +r/w +First pixel to read in the X direction. +
0 is the first pixel on the detector.MIN_X +$(P)$(R)MinX +
$(P)$(R)MinX_RBVlongout +
longin+ +ADMinY +asynInt32 +r/w +First pixel to read in the Y direction. +
0 is the first pixel on the detector.MIN_Y +$(P)$(R)MinY +
$(P)$(R)MinY_RBVlongout +
longin+ +ADSizeX +asynInt32 +r/w +Size of the region to read in the X direction +SIZE_X +$(P)$(R)SizeX +
$(P)$(R)SizeX_RBVlongout +
longin+ +ADSizeY +asynInt32 +r/w +Size of the region to read in the Y direction +SIZE_Y +$(P)$(R)SizeY +
$(P)$(R)SizeY_RBVlongout +
longin+ +ADReverseX +asynInt32 +r/w +Reverse image in the X direction +
(0=No, 1=Yes)REVERSE_X +$(P)$(R)ReverseX +
$(P)$(R)ReverseX_RBVlongout +
longin+ +ADReverseY +asynInt32 +r/w +Reverse image in the Y direction +
(0=No, 1=Yes)REVERSE_Y +$(P)$(R)ReverseY +
$(P)$(R)ReverseY_RBVlongout +
longin+ +Image and trigger modes ++ +ADImageMode +asynInt32 +r/w +Image mode (ADImageMode_t). +IMAGE_MODE +$(P)$(R)ImageMode +
$(P)$(R)ImageMode_RBVmbbo +
mbbi+ +ADTriggerMode +asynInt32 +r/w +Trigger mode (ADTriggerMode_t). +TRIGGER_MODE +$(P)$(R)TriggerMode +
$(P)$(R)TriggerMode_RBVmbbo +
mbbi+ +Data type ++ +ADDataType +asynInt32 +r/w +Data type (NDDataType_t). +DATA_TYPE +$(P)$(R)DataType +
$(P)$(R)DataType_RBVmbbo +
mbbi+ +Actual dimensions of image data ++ +ADImageSizeX +asynInt32 +r/o +Size of the image data in the X direction +IMAGE_SIZE_X +$(P)$(R)ImageSizeX_RBV +longin ++ +ADImageSizeY +asynInt32 +r/o +Size of the image data in the Y direction +IMAGE_SIZE_Y +$(P)$(R)ImageSizeY_RBV +longin ++ +ADImageSize +asynInt32 +r/o +Total size of image data in bytes +IMAGE_SIZE +$(P)$(R)ImageSize_RBV +longin ++ +Acquisition time and period ++ +ADAcquireTime +asynFloat64 +r/w +Acquisition time per image +ACQ_TIME +$(P)$(R)AcquireTime +
$(P)$(R)AcquireTime_RBVao +
ai+ +ADAcquirePeriod +asynFloat64 +r/w +Acquisition period between images +ACQ_PERIOD +$(P)$(R)AcquirePeriod +
$(P)$(R)AcquirePeriod_RBVao +
ai+ +Number of exposures and number of images ++ +ADNumExposures +asynInt32 +r/w +Number of exposures per image to acquire +NEXPOSURES +$(P)$(R)NumExposures +
$(P)$(R)NumExposures_RBVlongout +
longin+ +ADNumImages +asynInt32 +r/w +Number of images to acquire in one acquisition sequence +NIMAGES +$(P)$(R)NumImages +
$(P)$(R)NumImages_RBVlongout +
longin+ +Acquisition control ++ +ADAcquire +asynInt32 +r/w +Start (1) or stop (0) image acquisition. This record is linked to an EPICS busy record + that does not process its forward link until acquisition is complete. Clients should write + 1 to the Acquire record to start acquisition, and wait for Acquire to go to 0 to know that + acquisition is complete. +ACQUIRE +$(P)$(R)Acquire +bo ++ +File saving parameters ++ +ADFilePath +asynOctet +r/w +File path +FILE_PATH +$(P)$(R)FilePath +
$(P)$(R)FilePath_RBVwaveform +
waveform+ +ADFileName +asynOctet +r/w +File name +FILE_NAME +$(P)$(R)FileName +
$(P)$(R)FileName_RBVwaveform +
waveform+ +ADFileNumber +asynInt32 +r/w +File number +FILE_NUMBER +$(P)$(R)FileNumber +
$(P)$(R)FileNumber_RBVlongout +
longin+ +ADFileTemplate +asynOctet +r/w +Format string for constructing ADFullFileName from ADFilePath, ADFileName, and ADFileNumber +FILE_TEMPLATE +$(P)$(R)FileTemplate +
$(P)$(R)FileTemplate_RBVwaveform +
waveform+ +ADFullFileName +asynOctet +r/o +Full file name +FULL_FILE_NAME +$(P)$(R)FullFileName_RBV +waveform +
waveform+ +ADAutoIncrement +asynInt32 +r/w +Auto-increment flag (0=No, 1=Yes) +AUTO_INCREMENT +$(P)$(R)AutoIncrement +
$(P)$(R)AutoIncrement_RBVbo +
bi+ +ADAutoSave +asynInt32 +r/w +Auto-save flag (0=No, 1=Yes) +AUTO_SAVE +$(P)$(R)AutoSave +
$(P)$(R)AutoSave_RBVbo +
bi+ +ADFileFormat +asynInt32 +r/w +File format. The format to write/read data in (e.g. TIFF, netCDF, etc.) +FILE_FORMAT +$(P)$(R)FileFormat +
$(P)$(R)FileFormat_RBVmbbo +
mbbi+ +ADWriteFile +asynInt32 +r/w +Manually save the most recent image to a file when value=1 +WRITE_FILE +$(P)$(R)WriteFile +longout ++ +ADReadFile +asynInt32 +r/w +Manually read a file when value=1 +READ_FILE +$(P)$(R)ReadFile +longout ++ +Status information ++ +ADStatus +asynInt32 +r/o +Acquisition status (ADStatus_t) +STATUS +$(P)$(R)DetectorState_RBV +mbbi ++ +ADStatusMessage +asynOctet +r/o +Status message string +STATUS_MESSAGE +$(P)$(R)StatusMessage_RBV +waveform ++ +ADStringToServer +asynOctet +r/o +String from driver to string-based vendor server +STRING_TO_SERVER +$(P)$(R)StringToServer_RBV +waveform ++ +ADStringFromServer +asynOctet +r/o +String from string-based vendor server to driver +STRING_FROM_SERVER +$(P)$(R)StringFromServer_RBV +waveform ++ +ADImageCounter +asynInt32 +r/w +Counter that increments by 1 each time an image is acquired +IMAGE_COUNTER +$(P)$(R)ImageCounter +
$(P)$(R)ImageCounter_RBVlongout +
longin+ +N/A +N/A +r/o +Rate (Hz) at which ImageCounter is incrementing. Computed in database. +N/A +$(P)$(R)ImageRate_RBV +calc ++ +Shutter control. Note: no areaDetector drivers yet implement shutter control, + and these parameters may change in the near future. ++ +ADShutter +asynInt32 +r/w +Shutter control (ADShutterStatus_t) +SHUTTER +$(P)$(R)ShutterMode +
$(P)$(R)ShutterMode_RBVmbbo +
mbbi+ +Image data ++ +NDArrayData +asynGenericPointer +r/w +The image data as an NDArray object +NDARRAY_DATA +N/A. EPICS access to image data is through NDStdArrays plugin. +N/A ++ +asyn port information ++ +N/A +N/A +N/A +The name of the asyn port for this driver +N/A +$(P)$(R)PortName_RBV +stringin ++ N/A +N/A +N/A +asyn record to control debugging (asynTrace) +N/A +$(P)$(R)AsynIO +asyn -pilatusROI_N.template is loaded for each ROI with the following macro parameters: -
- -
- +The following is the MEDM screen that provides access to the parameters in ADStdDriverParams through +records in ADBase.template. This is a +top-level MEDM screen that will work with any areaDetector driver. Note however that many drivers will not implement all +of these parameters, so detector-specific MEDM screens should generally be created that only display the EPICS PVs +for the features implemented for that detector. Note that the section of the screen labeled "Shutter" is not currently +implemented for any areaDetector driver, and is subject to change in the near future.- Macro parameter -Description -- -$(DET)PV name prefix. This identifies this Pilatus detector from others that may be - running on the same subnet. -- -$(N)The number of this ROI. Starts with 1. -- -$(XMIN)The minimum value of X for this ROI. Starts with 0. -- -$(XMAX)The maximum value of X for this ROI. Starts with 0. -- -$(YMIN)The minimum value of Y for this ROI. Starts with 0. -- -$(YMAX)The maximum value of Y for this ROI. Starts with 0. -- -$(BGD_WIDTH)The background width for this ROI. - If BGD_WIDTH <=0 then no background subtraction is done, and NetCounts=TotalCounts. -- - -$(NCHANS)The maximum number of elements in the WFTotalCounts and WFNetCounts waveform arrays. - This sets the maximum value of NImages for collecting ROI arrays. --The pilatusROIs SNL program is started with the following macro parameters: -
- -
- -- Macro parameter -Description -- -DETPV name prefix. This identifies this Pilatus detector from others that may be - running on the same subnet. -- -PORTThe name of the asyn port connected to the Pilatus via a TCP/IP socket. -- - -NROISThe number of ROIs loaded in the substitutions file with pilatusROI_N.template. - Maximum=32. --The following is an example st.cmd startup script: -
-< envPaths - -### -# Load the EPICS database file -dbLoadDatabase("$(PILATUS)/dbd/pilatus.dbd") -pilatus_registerRecordDeviceDriver(pdbbase) - -### -# Create the asyn port to talk to the Pilatus on port 41234. -drvAsynIPPortConfigure("pilatus","gse-pilatus1:41234") -# Set the input and output terminators. -asynOctetSetInputEos("pilatus", 0, "\030") -asynOctetSetOutputEos("pilatus", 0, "\n") -# Define the environment variable pointing to stream protocol files. -epicsEnvSet("STREAM_PROTOCOL_PATH", "$(PILATUS)/pilatusApp/Db") - -### -# Specify where save files should be -set_savefile_path(".", "autosave") - -### -# Specify what save files should be restored. Note these files must be -# in the directory specified in set_savefile_path(), or, if that function -# has not been called, from the directory current when iocInit is invoked -set_pass0_restoreFile("auto_settings.sav") -set_pass1_restoreFile("auto_settings.sav") - -### -# Specify directories in which to to search for included request files -set_requestfile_path("./") -set_requestfile_path("$(AUTOSAVE)", "asApp/Db") -set_requestfile_path("$(CALC)", "calcApp/Db") -set_requestfile_path("$(SSCAN)", "sscanApp/Db") -set_requestfile_path("$(PILATUS)", "pilatusApp/Db") - -### -# Load the save/restore status PVs -dbLoadRecords("$(AUTOSAVE)/asApp/Db/save_restoreStatus.db", "P=PILATUS:") - -### -# Load the substitutions for for this IOC -dbLoadTemplate("PILATUS_all.subs") -# Load an asyn record for debugging -dbLoadRecords("$(ASYN)/db/asynRecord.db", "P=PILATUS:,R=asyn1,PORT=pilatus,ADDR=0,IMAX=80,OMAX=80") - -# Load sscan records for scanning -dbLoadRecords("$(SSCAN)/sscanApp/Db/scan.db", "P=PILATUS:,MAXPTS1=2000,MAXPTS2=200,MAXPTS3=20,MAXPTS4=10,MAXPTSH=2048") - -### -# Set debugging flags if desired -#asynSetTraceIOMask("pilatus",0,2) -#asynSetTraceMask("pilatus",0,3) - -### -# Start the IOC -iocInit - -### -# Save settings every thirty seconds -create_monitor_set("auto_settings.req", 30, "P=PILATUS:") - -### -# Start the SNL program -seq(pilatusROIs, "DET=PILATUS:, PORT=pilatus, NROIS=16") -- -The following is the substutitions file PILATUS_all.subs referenced above. -It creates 16 ROIS, and defines 5 valid ones: the entire chip, and the 4 quadrants of the chip: --ffile $(PILATUS)/db/pilatusROI.template { -pattern -{DET, NXPIXELS, NYPIXELS, NPIXELS, PORT} -{PILATUS:, 487, 195, 94965, pilatus} -} - -file $(PILATUS)/db/pilatusROI_N.template { -pattern -{DET, N, XMIN, XMAX, YMIN, YMAX, BGD_WIDTH, NCHANS} -{PILATUS:, 1, 0, 486, 0, 194, 1, 2000} -{PILATUS:, 2, 0, 243, 0, 97, 1, 2000} -{PILATUS:, 3, 0, 243, 98, 194, 1, 2000} -{PILATUS:, 4, 244, 486, 0, 97, 1, 2000} -{PILATUS:, 5, 244, 486, 98, 194, 1, 2000} -{PILATUS:, 6, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 7, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 8, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 9, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 10, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 11, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 12, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 13, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 14, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 15, -1, -1, -1, -1, 1, 2000} -{PILATUS:, 16, -1, -1, -1, -1, 1, 2000} -} -- -
- -- MEDM screens
-The following show the MEDM screens that are used to control the pilatusROI software.
- -
- -pilatusROI.adlis the main screen used to control the pilatusROI SNL -program. All records except those that are specific to each ROI are accessed through this -screen. -pilatusROI.adl
-
- -pilatus8ROIs.adlis used to define the ROIs, and to display the statistics for -each ROI. In this example there are 2 valid ROIs defined. ROI 1 is a small rectangle near the center -containing the Bragg diffraction peak from a crystal. ROI 2 is the entire chip. -pilatus8ROIs.adl
-
- -pilatusROI_waveform.adlis used to plot the net or total counts in an ROI when -NImages>1. In this example the plot is the net counts in ROI 1 as the diffractometer chi was scanned -+- 1 degree with 1000 points at .02 seconds/point. This was done with the SPEC command --lup chi -1 1 1000 .02 -
-using trajectory scanning on a Newport kappa diffractometer. This was a compound motor scan with the -Newport XPS putting out pulses every .02 seconds. These pulses triggered the Pilatus in External Enable mode. -The pilatusROI program read each TIFF file as it was created and updated this plot every 0.2 seconds. -The total time to collect this scan with 1000 images was 20 seconds. -pilatusROI_waveform.adl
-
- -scan_more.adlis used to define a scan. In this example the sscan record is set up -to scan the ThresholdEnergy PV and to collect the total counts in ROI2, which was defined to include -the entire detector. -scan_more.adl
-
- -scanDetPlot.adlis used to plot the results of a scan after it is complete. -In this example the total counts in ROI 2 are plotted as a function of the ThresholdEnergy as it was -scanned from 3000 to 10000 eV in 250 eV steps. The source was Fe55, and the cut-off is at 6 keV, as -expected for the Mn Ka and Mn Kb x-rays that this source produces. -scanDetPlot.adl
-
- -asynRecord.adlis used to control the debugging information printed by the asyn TCP/IP driver -(asynTraceIODriver) and the SNL program (asynTraceIODevice). -asynRecord.adl
-
- -asynOctet.adlcan be used to send any command to camserver and display the response. It can -be loaded from the More menu in asynRecord.adl above. -asynOctet.adl
-
- -- IDL Image Display Client
epics_image_display-that can be used to display the ImageData PV that pilatusROI sends over EPICS. This IDL -client is available as source code (which requires an IDL license), and also as a pre-built IDL .sav -file that can be run for free under the IDL Virtual Machine. This IDL program can run on any machine that IDL -runs on, and that has the ezcaIDL shareable library built for it. This includes Windows, Linux, Solaris, and Mac. -epics_image_displayis included in the -CARS IDL imaging software. - --The control window for
epics_image_displayis shown below. It has fields to input the name of -the EPICS PV with the image data, which is $(DET)ImageData in the case of pilatusROI. It also has fields -for the number of pixels in the X and Y directions. This is needed because EPICS waveform records are -1-dimensional only, and so do not contain the information on the number of rows and columns in the image. - -Main window for IDL epics_image_display
-
- -epics_image_displayuses the routine -image_display.pro -to display the images. This routine displays row and column profiles as the cursor is moved. It allows -changing the color lookup tables, and zooming in and out with the left and right mouse buttons. The following -is an example ofimage_displaydisplaying a Pilatus image with an Fe55 source in front of the detector. - -IDL image_display with Fe55 radioactive source
-
- -- SPEC interface
-# need some more globals (kludge) -global PILATUS_ROI_PV -global PILATUS_IMGPATH_PV -global PILATUS_FNAME_PV -global PILATUS_FILENUMBER_PV -global PILATUS_FILEFORMAT_PV -global PILATUS_EXPSRTM_PV -global PILATUS_NFRAME_PV -global PILATUS_EXPPRD_PV -global PILATUS_NEXPFRM_PV -global PILATUS_ACQ_PV -global PILATUS_ACQMODE_PV - -############################################################### -def _setup_img '{ - local j, str - - # PILATUS_PREFIX should be detector aquisition pv (GSE-PILATUS1:) - if ( PILATUS_PREFIX == "") PILATUS_PREFIX = "GSE-PILATUS1:" - PILATUS_PREFIX = getval("Enter PILATUS pv prefix",PILATUS_PREFIX) - - # rois pvs - PILATUS_ROI_PV = PILATUS_PREFIX "ROI1NetCounts" - PILATUS_IMGPATH_PV = PILATUS_PREFIX "FilePath" - PILATUS_FNAME_PV = PILATUS_PREFIX "Filename" - PILATUS_FILENUMBER_PV = PILATUS_PREFIX "FileNumber" - PILATUS_FILEFORMAT_PV = PILATUS_PREFIX "FileFormat" - PILATUS_EXPSRTM_PV = PILATUS_PREFIX "ExposureTime" - PILATUS_NFRAME_PV = PILATUS_PREFIX "NImages" - PILATUS_EXPPRD_PV = PILATUS_PREFIX "ExposurePeriod" - PILATUS_NEXPFRM_PV = PILATUS_PREFIX "NExposures" - PILATUS_ACQ_PV = PILATUS_PREFIX "Acquire" - PILATUS_ACQMODE_PV = PILATUS_PREFIX "AcquireMode" -... - -def epics_pilatus_count '{ -... - # write to data base fields - # Need to convert path from string to byte array - # Note: we use the "wait" parameter in epics_put here (new to spec5.7.02) so that - # it uses ca_put_callback, to know that all PVs have been processed - # before we start counting. Use 1 second timeout, will actually be - # much faster than this unless something is wrong. - array _temp[256] - _temp = PILATUS_IMAGE_DIR - # Do not change path for now - #epics_put(PILATUS_IMGPATH_PV,_temp, 1) - epics_put(PILATUS_FNAME_PV,img_fname, 1) - epics_put(PILATUS_FILENUMBER_PV,NPTS, 1) - epics_put(PILATUS_FILEFORMAT_PV,_fileformat, 1) - epics_put(sc_prtm_pv,cnt_time_val, 1) - epics_put(PILATUS_EXPSRTM_PV,cnt_time_val, 1) - epics_put(PILATUS_ACQMODE_PV,0, 1) # Internal trigger - epics_put(PILATUS_NFRAME_PV, 1, 1) - epics_put(PILATUS_NEXPFRM_PV, 1, 1) - - -def user_getcounts '{ - local pv_roi, j, pv - -... - # using image_count routine - } else if ( EPICS_COUNT == 4 ) { - S[iroi] = 0 - S[iroi] = epics_get(PILATUS_ROI_PV) -- -
- -- Performance measurements
-
-
- AcquireMode=Internal, NImages=1000, ExposureTime=.005, ExposurePeriod=.01, NExposures=1. - The time to collect this series should be exactly 10.0 seconds. - The actual time was measured using the EPICS camonitor program. It printed the time when - acquisition was started (Acquire changed to Busy) and when acquisition was complete (Acquire changed to Done). - The time was 10.274 seconds. This includes the time for camserver to save all 1000 images to disk (366 MB), - and for pilatusROI to read each file, correct the bad pixels and flat field, compute the ROIs, and post the ROIs - to EPICS. It also posted the images to EPICS at 1Hz (10 images total). The total additional time was less - than 0.3 seconds for all 1000 images. -
- AcquireMode=Internal, NImages=1, ExposureTime=.01, NExposures=1. - An EPICS sscan record was used to collect 1000 points. - There were no positioner PVs (to eliminate motor overhead). - The only detector trigger was the pilatusROI Acquire PV. The only detector PV was ROI1TotalCounts. - In this mode camserver is being told to individually collect each file. - If there were no overhead then time to collect this series should be exactly 10.0 seconds. - The actual time measured using the EPICS camonitor program was 49.161 seconds. - The overhead is thus 39.161 seconds, or 39 ms per point. - In this single-frame mode pilatusROI is thus able to collect >20 images/second. - For comparison, another measurement was done using the same EPICS sscan record, - but using a Joerger VSC16 scaler as the detector - trigger and detector. The preset time was also .01 seconds. The elapsed time for a 1000 point scan was - 16.068 seconds, so the overhead was 6.068 seconds, or 6 ms per point. -
- AcquireMode=Ext. Enable, NImages=1000, NExposures=1.
- SPEC was used to collect 1000 points using
- trajectory scanning mode
- with the Newport XPS motor controller. The following SPEC command was used:
-
- lup chi -2 2 1000 .015 -
- This tells SPEC to do a relative scan of the chi axis from -2 degrees to +2 degrees with 1000 points - at .015 seconds/point. On our kappa diffractometer this entails a coordinated motion of the phi, kappa - and omega axes. The EPICS trajectory scanning software downloads the non-linear trajectory that SPEC computes - into the XPS controller, which executes it. As the motors are moving the XPS outputs synchronization pulses - at the period of the collection time, .015 seconds in this case. These pulses are stretched - (see Hardware notes below) and used as the external input to the Pilatus. - The time to execute this scan should be 15.0 seconds. The actual time was 16.3 seconds, measured - using camonitor on the Acquire PV. Again, this includes the time for camserver to save all 1000 images to disk - (366 MB), and for pilatusROI to read each file, correct the bad pixels and flat field, compute the ROIs, and post the ROIs - to EPICS. It also posted the images to EPICS at 1Hz (15 images total). The total additional time was less - than 1.3 seconds for all 1000 images. As soon as the acquisition was complete SPEC plotted the net counts in - the first ROI (containing the Bragg peak) as follows: -1000 point SPEC scan with 15 ms per point collected in 16.3 seconds
-
- For comparison this identical scan was executed in traditional step-scanning mode, where the motors stopped - at each point in the scan. The Pilatus was run in Internal mode with NImages=1. The total time for the scan - was 870 seconds (more than 14 minutes), compared to 16.3 seconds in trajectory mode. Most of this overhead - is the settling time for the motors, with only a small fraction due to the Pilatus single-exposure mode. The - trajectory scanning mode is thus more than 50 times faster to execute the identical SPEC scan. -
- -- Hardware notes
Trigger pulses
-The Pilatus supports 3 types of external triggering. In External Trigger mode (the camserver ExtTrigger command) -the Pilatus uses the programmed values of ExposureTime, ExposurePeriod, NImages and NExposures. It waits for -a single external trigger, then waits for Delay seconds and then collects the entire sequence. It is very similar -to Internal mode with NImages>1, except that it waits for a trigger to begin collecting the sequence. - -In External Enable mode (the camserver ExtEnable command) the Pilatus uses the external signal to control acquisition. -Only NImages and NExposures are used, ExposureTime and ExposurePeriod are not used. When the signal -is high the detector counts, and on the transition to low it begins its readout. - -
In External MultiTrigger Mode (the camserver ExtMTrigger command) the Pilatus uses the programmed ExposureTime, -in addition to NImages and NExposures. Each external trigger pulse causes the Pilatus to collect one image -at the programmed exposure time. This mode works well with a trigger source like the Newport motor controllers -or the SIS380x multichannel scaler, -that put out a short trigger pulse for each image. One only needs to take care that the time between external trigger -pulses is at least 4msec longer than the programmed exposure time, to allow time for the detector to read out before -the next trigger pulse arrives. - -
When using the External Enable mode, we use an inexpensive analog pulse generator -to convert the trigger pulses from the MM4005 and XPS to a form suitable for External Enable mode -with the Pilatus. This is the solution we have developed that seems to be reliable: -
-
-
- The synchonization pulses from the Newport MM4005 or XPS controller are input into the external next pulse - (channel advance, control signal 1) input of the SIS3801 multiscaler. - This is the normal configuration used for MCS counting - without the Pilatus in trajectory scanning mode. -
- The Copy In Progress (CIP) output of the SIS3801 (control signal 5) is connected to the Trigger Input of a
- Tenma TGP110 10 MHz Pulse Generator. CIP will output a pulse whenever the SIS3801 does a channel advance,
- either in external mode with the motor controller pulse input, or in internal timed channel advance mode.
- The TGP100 Pulse Generator is configured as follows:
-
-
-
- Trigger Input connected to CIP output of SIS3801. -
- Triggered mode. -
- Complement output. -
- Pulse duration set with knobs to 3msec. -
- TTL Output connected to the External Input of the Pilatus. -
- With this configuration the SIS3801 CIP output is normally at 5V, and outputs a 0V pulse 1 microsecond long. - The trailing (rising) edge of that pulse triggers the TGP110. The TGP110 TTL output is also normally at 5V, - and outputs a 0V pulse 3 milliseconds long each time the SIS3801 pulses. That output is connected to the - Pilatus External Input. In External Enable mode when Pilatus External Input is - high the Pilatus is counting. When the External Input is low the Pilatus reads out. The readout time is - set via the knobs on the pulse generator to be 3 ms, which is close to the minimum time allowed on the - Pilatus. -
Detector Voltage
-When we were initially testing the Pilatus in the lab, we had many errors in External Enable mode, where it did -not seem to be seeing the external pulses. camserver would get DMA timeouts, and need to be restarted. Dectris -said these were happening because the cables on our detector are longer than normal, and the voltage -drop from the power supply to the detector was leading to marginal voltage values. They suggested shortening -the cables or increasing the supply voltage slightly. When moving the detector to the hutch these -problems initially went away. However, they then recurred, and we fixed the problem by increasing -the power supply voltage from 4.4 to 4.7 volts at the detector. --Dectris has since informed me that they have increased the power supply voltage on all new Pilatus systems, -so this should no longer be an issue. - - -
- -- Restrictions
-
-
- Limited to TIFF file format. - camserver can save files in other formats, but pilatusROI can currently only read TIFF files. - Furthermore, it - has a very simple TIFF reader. It does not read the TIFF tags at all, but simply assumes that there - is a 4096 byte header, followed by the 32-bit image data. The size of the image data is controlled - by the NXPixels and NYPixels PVs, which thus must be correctly set. -
- The EPICS IOC should be run on the same computer as camserver. - This is not strictly necessary, and places a small additional load on the CPU and network - on that computer. However, we have found that TIFF files are available to be read within 10ms after - camserver says they have been written if the IOC is running on the same machine as camserver. This is true - even if the files are being saved on a remote NFS or SMB file system. On the other hand, if the IOC and - camserver are running on separate machines, then the filesystem can wait up to 1 second after camserver - says the TIFF file has been written before the IOC can read it. This is true even if the files are being - written to the computer that the IOC is running on! This 1 second delay is often unacceptable for fast - single-exposure scans, i.e. with NImages=1. -
- pilatusROI keeps retrying to read each TIFF file until - the modification date of the TIFF file is after the time that the exposure command was issued. - If it did not - do this check then it could be reading and displaying old files that happen to have the same name as the - current files being collected. This check requires that the computer that is running the soft IOC must - have its clock well synchronized with the - clock on the computer on which the files are being written - (i.e. the computer generating the file modification time). - If the clocks are not synchronized then the files may appear to be stale when they are not, - and pilatusROI will time out. pilatusROI actually tolerates up to 10 second clock skew betweeen the computers - but any more than this may lead to problems. -
- The Abort PV does not always work because camserver does not reliably implement the "K" command to stop - an exposure sequence. In particular with NImages>1 camserver seems to often ignore - the K command completely, even with exposure times/periods as long as 10 seconds. - With NImages=1 it does kill the exposure after a few seconds. -
- The following items are hardcoded in the SNL program. They can be changed before compiling if necessary.
- Some could be changed to be EPICS PVs, so they could be controlled at run-time, but others must be defined
- at compile time because of limitations in the SNL semantics.
-
-
-
- MAX_MESSAGE_SIZE=256 The maximum size of message to/from camserver. -
- MAX_FILENAME_LEN=256 The maximum size of a complete file name including path and extension. -
- FILE_READ_DELAY=.01 seconds. The time between polling to see if the TIFF file exists - or if it is the expected size. -
- MAX_BAD_PIXELS=100 The maximum number of bad pixels. -
- MAX_ROIS=32 The maximum number of ROIs -
- MAX_CHANS=2000 The maximum number of points in the ROI waveform arrays. -
- MAX_PIXELS=94965 The maximum number of pixels in the ImageData array. Because of SNL semantics - limitations this value must be defined at compile time, and cannot be changed at run time. -
- MAX_READ_ERRORS=3 The maximum number of TIFF file read errors before the SNL gives up and aborts - acquisition. -
