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Roper Photometric User's Manual

1. 1 to light and charge pattern accumulates in the parallel register Charge in the parallel register is shifted one row The first row is shifted into the serial register The charge from the next pixel is shifted to the output node The charge at the out put node is collected for signal processing AN The first pixel is serially shifted into the output node Steps 5 and 6 are re peated until the entire serial register is read out The charge at the out put node is collected for signal processing Steps 2 through 7 are repeated until the entire parallel register is read out All CCD imagers depend on the efficient transport of charge from the photosites to the output amplifier Because the charge from wells located far from the output amplifier must undergo many hundreds of transfers the charge transfer efficiency CTE is important A scientific grade CCD imager exhibits a CTE of 0 99999 where 1 0 is perfect CTE is of special concern at low charge levels where a small loss of charge can cause significant degradation of the image 32 Advanced Camera Operation Manual A subarray is speci fied The charge is fast shifted toward the output node Subarrays Binning Subarray Readout UE v
2. The CCD is exposed The charge in the The first row is to light and a charge subarray is fast shifted into the serial pattern accumulates shifted toward the register in the subarray serial register Steps 6 and 7 are re peated until the entire serial register is read out 9 Steps 4 through 8 The first pixel of the The charge at the output are repeated until subarray is shifted into node is collected for the entire subarray the output node signal processing is read out It is not necessary to read out all of the pixels on the parallel register One or more subarrays on the parallel register may be specified and read out with a resultant reduction in pixel count and increase in readout speed Subarray Readout illustrates the subarray readout concept Binning is a technique of combining charge from adjacent pixels during the readout process Binning improves the signal to noise ratio and extends the dynamic range of the CCD imager but at the expense of spatial resolution Binning is thus most useful in applications where resolution in one or both axes is not of primary concern Because binning reduces the number of pixels to be processed and digitized readout speed is also increased As shown in Binned Readout on page 34 charge is collected in the normal fashion but the readout is programmed differently With parallel binning when charge is shifted from the parallel register into the serial register cha
3. 29 Theory of Operation soient hte re enm pedi o I eddie b Ren des 29 Potential Wells et dte eee ie alone ie 29 Charge Transfers on ee e e ee eee e eri eden ie eet e PR lr CREE ede 30 Classical CCD Implementations eee ee eene nens 31 CCD Readoutus us eR SR ro Te TET ve Re ee edt 32 SUD ATES Y eese LOS CU nt nmau tue a dem 33 BINDING er oia tacet daria Eneas 33 Time Delay Integration enne peer ene 34 CCD Architectut s e este tente c eerie 35 Full Frames 2i ere eise 35 Br rdeLranstet eea su sina aue m 35 Interline Transfer sue ede eter p ebrio ERO p e E Eee ers 36 CCD Camera Implementations nre tetendit tete inn atat itere ri ae 37 Resolution isset an eee etel meten np s 37 37 Spectral Response lei a e i aa 38 FIDCTOPUICS 5 5 2 m reet te pite e be n eee E shatters 39 SOULCES OL ne pe e d E eie I e ea 39 e ee e 39 Preamplifier Noise 5 ut doge esa iri bue ceret b art erras 39 Dark Cu rrentNOlse ed e be tee Meet rn ER ED d e EE 40 MAG SOLS ht e vete tene bt t e ent a ir teet te rae deel 40 Additional Reading enn terr eet PER ente rit re e D Nen 41 Index edd 43 iv Advanced Camera Operation Manual Chapter
4. READ DATA FROM THE CCD this is the only way to output image pixels Script begin this must be the first verb in a script Script end contin clear this must be the last verb in a script if contin clear is non zero the CCD is left in continuous clear mode shift number of lines shift the parallel register several lines using a mode shift image to storage redundant but useful for frame transfer CCDs shift mode is parallel shift mode image and storage normal shift mode is alt parallel shift mode image and storage alternate shift mode ism parallel shift mode image and storage shift mode ism alt parallel shift mode image and storage MPP alt shift mode s parallel shift mode storage array normal shift mode s alt parallel shift mode storage array alternate shift mode sm parallel shift mode storage array MPP shift mode sm alt parallel shift mode storage array MPP alternate shutter close close the camera shutter shutter open open the camera shutter clear parallel clear count This function clears the parallel register the entire CCD the premask area active area and postmask area clear count times where c1ear count must be greater than zero The function puts the CCD into an image and storage shifting mode then shifts the entire parallel register into the serial register thus clearing the CCD of
5. The illustration is simplified to emphasize the concept To ensure effective charge transfer charge propagation actually occurs in a channel buried just below the surface where there is no interference from interface states The gates actually overlap to create the drift field required for efficient charge transfer 30 Advanced Camera Operation Manual Classical CCD Implementations The one dimensional charge transfer concept can be extended to two dimensions Buried channels arranged in parallel establish columns charge cannot migrate between columns Along each column charge is contained in individual potential wells by a multiphase gate structure as discussed for the one dimensional case The result is a two dimensional array of independent potential wells A Typical CCD Imager shows a stylized CCD imager The large square array is the parallel register In this example the parallel register contains 262 144 independent potential wells called picture elements or pixels Each pixel is 20 um square and contains a single charge packet A Typical CCD Imager lt 20 u gt 8 Parallel clocks Output node Pixel columns E x n o BES 2 i e 5 Parallel Register ES a 512 x 512 pixels o o 10 25 mm The seri
6. Display Verbs The pixel display verb is not sent to the camera and does not affect data collection However once the data has been collected the application examines the script the pixel display verbs and any loop commands From this information the application determines how to display the images Note that the pixel_display function may appear inside loops outside loops or both If you use pixel_readout anywhere in the script you must also use pixel display If the script does not include pixel readout pixel display must not appear Syntax Summary The following is a summary of ICL script syntax Script Every script must start with script begin and end with script end Match each 1oop begin witha loop Opening comments These don t need to be inside comment marks script begin verb verb param param loop begin loop count verb param loop end pixel readout param param param param param pixel display param param script end param Whitespace Whitespace is never required When whitespace is allowed the following are allowed character space I J L M non nested comments ASCII name space LF FF CR dec value 32 9 10 12 13 47 42 42 47 C generation t n f r ud LR 4 Function Syntax verb verb name param param param whitespace verb param verb param e Verb names functions are always lowercase Some functions contain underscores e Every
7. Photometrics Advanced Camera Operation ROPER SCIENTIFIC BEYOND IMAGING Copyright 2002 Roper Scientific Inc 3440 East Britannia Drive Tucson Arizona 85706 Tel 520 889 9933 Fax 520 295 0299 All rights reserved No part of this publication may be reproduced by any means without the written permission of Roper Scientific Inc Printed in the United States of America Photometrics and Roper Scientific are trademarks and Metachrome PVCAM and PXL are registered trademarks of Roper Scientific Inc The information in this publication is believed to be accurate as of the publication release date However Roper Scientific Inc does not assume any responsibility for any consequences including any damages resulting from the use thereof The information contained herein is subject to change without notice Revision of this publication may be issued to incorporate such change 57 039 001 Rev C1 LIMITED WARRANTY Roper Scientific Analytical Instrumentation Roper Scientific Inc makes the following limited warranties These limited warranties extend to the original purchaser only and no other purchaser or transferee Limited One 1 Year Warranty Roper Scientific warrants this product against defects in materials or workmanship for a period 1 year after the date of original invoice During this period Roper Scientific will repair a defective product or part without charge to you You must deliver the entire
8. Any of the following examples are legal loop_end loop_end 1 _ loop_end comments count as whitespace loop_end Parameters must be positive integers of normal numeric digits 0 9 None of the following symbols are acceptable oie E es e M Single Parameter Functions Multiple Parameter Functions Verbs Some functions require a single parameter Fractional decimal and negative values are not allowed Numeric expressions generate an error Whitespace can be included anywhere inside the parentheses The following parameters are legal loop_begin 50 3 loop begin 50 exposure count 5 loop begin 50 The following parameters are illegal whitespace befor contains a comma two numeric entries only one allowed minus sign is illegal numeric expressions not allowed loop begin 50 parentheses loop begin 50 loop begin 50 0 loop begin loop_begin A few functions require multiple parameters There are no variable argument lists so each parameter is always required The parameters must be separated by commas Insert whitespace as desired The following examples are legal pixel_readout 0 100 1 50 2 5 pixel_readout 0 100 I 50 De pixel_readout MAIN FUNCTION 0 serial offset of 0 100 serial size value 100 1 serial binning 50 parallel size par bin 2 A verb describes
9. fill factor The sensitivity of a CCD imager to light is determined by system noise level discussed later in this chapter and quantum efficiency Quantum efficiency measures the sensor s efficiency in generating electronic charge from incident photons Electron hole pairs are produced by photons in the region from 400 to 1100 nm Within the visible spectrum the photon to electron conversion factor is less than unity and it varies as a function of wavelength At a given wavelength the creation of charge from incident light is intrinsically linear Chapter 3 Advanced CCD Theory 37 Spectral Response Light normally enters the CCD through the gates of the parallel register These gates are made of very thin polysilicon that is reasonably transparent at long wavelengths but becomes opaque at wavelengths shorter than 400 nm Thus at short wavelengths the gate structure attenuates incoming light Thinning With acid etching techniques CCDs can be uniformly thinned to approximately 10 and an image can be focused on the backside of the parallel register where there is no gate structure These thinned or backside illuminated CCDs exhibit high sensitivity to photons from the soft x ray to the near infrared regions of the spectrum Thick and Thinned CCDs illustrates the structures of both kinds of device Thick and Thinned CCDs Incoming light s SSS we Gn Incoming light Down Converters CCD spectral response can also be
10. of the shift instruction and various shifting modes this function does the operation more efficiently with a single instruction Please note that using this command leaves the parallel shifting mode set to shift mode s 10 Advanced Camera Operation Manual shift mode is Shift Image and Storage This is a parallel shifting mode that shifts the entire parallel register This mode can be used on all CCDs and uses the normal clocking method that is equivalent to MPP off The exception is for CCDs that require MPP clocking and in this case MPP on is used shift mode is alt Shift Image and Storage Alternate This is a parallel shifting mode that shifts the entire parallel register This mode can be used on all CCDs and uses the normal clocking method that is equivalent to MPP off The exception is for CCDs that require MPP clocking in this case MPP on is used In addition to the MPP style of shifting this function uses an alternate shifting mode see shi ft Unless an alternate shifting was loaded at the factory this mode is loaded with a default value identical to shift mode is shift mode ism Shift Image and Storage MPP This is a parallel shifting mode that shifts the entire parallel register This mode can only be used on CCDs that support MPP clocking If this mode is used on a non MPP CCD the script compiler generates an error and fails shift mode ism alt Shift Image and Storage MPP Alternate This is a parall
11. all charge This process can also be accomplished by using other functions such as using a number of shift commands with the proper shift mode but this function is easier to use Although the serial register runs continuously during the clearing there are some circumstances where the serial register may still contain charge This condition requires additional clearing with the clear serial command Note that this command leaves the parallel shifting mode set to shift mode is clear count must be between 1 and 65 535 inclusive clear serial clear count This function clears the serial register the prescan area active area and postscan area c1ear count times The function runs the serial register dumping any charge into the output node where the charge is transferred into the power supply c1ear count must be between 1 and 65 535 inclusive Chapter 2 ICL 7 clear until trig This function causes the CCD to enter clearing mode and continues clearing indefinitely until a trigger arrives Both the parallel and serial registers are continuously clearing moving charge toward and into the serial register then out When the trigger signal arrives the CCD finishes the current parallel shift the maximum delay is the time to shift 1 parallel row and then stops clearing Execution immediately continues with the next script instruction For more information concerning the pinouts and electrical specifications of the trigger port refer to
12. from the output data stream and displays them as a single rectangular image x pixels wide by y pixels tall Cross checking done during script setup ensures that the total number of pixels displayed matches the total number of pixels collected assuming that data collection is completed without errors In other words the total number of pixels read from the camera using pixel readout equals the total number of pixels displayed using pixel display Depending on the experiment design and the exact script used the individual pixel readout and pixel display instructions may or may not be closely matched However if the script contains any pixel readout instructions i e if one or more pixels are readout from the camera it must also contain at least one pixel display instruction Both x and y must be between 1 and 65 535 inclusive pixel readout s offset s size s bin p size p bin This function causes a block of pixels region to be first read out into the serial register then transferred into the output converter and digitizer The region must be immediately adjacent to the serial register when this instruction is given the parallel offset must be zero so you have to use the shift command to move the desired region to the edge of the parallel register Serial Register Ge n s_offset 0 0 Parallel Register For each row of the block the first s_offset pixels are skipped The next s_size pixels after the skipped
13. loop end shutter close DONE EXPOSING NOW READOUT A pixel readout 0 512 1 544 1 read out the entire storage array 27 loop_begin 544 pixel_display 512 1 display data as 512 separate lines Ky loop end Script end 0 FACTORY MODIFICATION For high speed spectroscopy the CCD must be able to shift ONLY the image array This accomplishes binning where charge accumulates on the top row of the storage array In this case the new shift table is loaded into one of the alternate shifting modes Specifically shift mode s alt is reloaded so it performs A parallel shifting mode this shifts the IMAGE array only on a frame transfer CCD It should be called shift mode I alt but that choice is not available Chapter 2 ICL 19 Error Codes This section lists the error codes that may appear when using ICL 10100 10101 10102 10103 10104 10105 10106 10107 10108 10109 10110 10111 10112 10113 10114 10115 10116 10117 10118 10119 10120 10121 10122 10123 10124 10125 10126 C101_ICL_UNKNOWN_ERROR C101 ICL LIB NOT INIT C101 ICL LIB INITED C101 ICL NO BEGIN C101 ICL END TOO SOON C101 ICL INST INVAL C101 ICL OPEN PAREN C101 ICL ILLEGAL CHAR C101 ICL BAD COMMA C101 ICL BAD NUMBER C101 ICL BAD CL PAREN C101 ICL NO SEMICOLON C101 ICL TOO MANY ARG C101 ICL TOO FEW ARG C101 ICL ARG I5 ZERO C101 ARG OVER 65K C101 INVALID C101 ICL OVER LOOP C101 ICL UNDER LOOP C101 U
14. panorama The result is that the front and back ends of the panorama gradually ramp up and down in brightness Script begin shift mode is redundant since script begin sets this anyway shutter open light is now falling on the CCD xf clear_parallel 5 make sure this CCD is cleared out clear_until_trig clear until acquire regular pulses f loop begin 8965 10 000 full panorama 1035 clean up size expose_until_trig readout each time trigger pulse received pixel_readout 0 1317 1 1 1 read exactly 1 row shift the rest over a4 loop end pixel readout 0 1317 1 1035 1 clean up read th ntire CCD pixel display 1317 10000 display this as one huge panoramic image shutter close script end 0 14 Advanced Camera Operation Manual Ratio Imaging 2 Frame Ratio This script collects two frames in quick succession for use in a ratio imaging experiment The camera is a PXL 37 a Marconi CCD37 10 CCD with a 512x512 image area and a masked 512x544 storage area Since the exposures must be tightly coordinated with the experimental setup the camera and experiment communicate with each other as follows 1 The script is set up and the camera is started note the camera shutter opens but it continuously clears until step 3 2 The final experimental setup is performed including turning on the primary lighting 3 The experimental hardware provides a rising edge TTL
15. region where the free electrons generated by incoming photons can be stored A potential well collects electronic charge from any source until the well is filled Practical potential well capacities range up to a million electrons Depletion depths range from a few micrometers up to tens of micrometers in specially prepared silicon Electrons freed by thermal agitation and by high energy particles are indistinguishable from those generated by photon interaction These dark electrons can have an adverse effect on the detection limits for photon induced charge The charge collected in a potential well must be brought to an output amplifier When a series of oxide and conductive gate structures is fabricated with multiple phases potential wells can be propagated through a silicon sheet This charge transfer concept is essential to understanding charge coupled devices When an appropriate sequence of potentials is applied to the gates the potential wells are propagated in the direction shown in the figure Charge Transfer Any charge that has been collected is carried along in the wells and the charge packets in each potential well remain separated Charge packets can be transferred thousands of times without significant loss of charge Charge Transfer Direction of Charge Transfer gt gt Phase 1 Phase 2 Phase 3 Gate l SiO layer to Q Q3 19 m O Oii hd t2 Qs tg
16. scripting or initialization function can be initialized first 22 Advanced Camera Operation Manual Class 101 ICL pl_exp_listerr_script 101 NAME pl exp listerr script if an error occurred during script processing list the exact position of that error SYNOPSIS boolean pl exp listerr script int16 hcam char ptr err char uns32 ptr err char num uns32 ptr err line uns32 ptr err ch in line DESCRIPTION By default this function returns zeros for all values indicating that no logical or syntactical error was spotted in the script This function resets each time pl exp setup script is called If the last call to p1 exp setup script generates an error this function returns the location where processing stopped of that error in the script string In some cases the location reported may just be past the location of the actual error The character that generated the error is returned in err char This will be character number err char numin the input string 0 indexed as with all C strings The script is also examined for line feed newlines etc in an attempt to divide the script into the separate lines used by common word processors The line number and character in the line are returned in err_line and err ch in line Both of those values are 1 indexed as is typical with text editors and word processors so that the first character in the script is character 1 of line 1 RETURN VALUE TRUE for success FALSE for a fail
17. values 3 Open the Shutter 13 p bin 9 p_size 9 Parallel register 31 Parameter functions multiple 4 single 4 Parameters 3 Parameters arguments Photon noise 39 Pinouts 8 12 pixel display 6 7 9 pixel readout 6 7 9 pl exp display script 21 pl exp init script 22 pl exp listerr script 23 pl exp setup script 24 pl exp start script 25 pl exp uninit script 26 Potential wells 29 Preamplifier noise 39 1 44 Advanced Camera Operation Manual Q R Quantum efficiency 37 Ratio Imaging 2 frame ratio 15 multi frame ratio 16 Readout sequence 32 Readout display 6 Repair camera 2 Rules of syntax 3 s bin 9 S offset 9 S size 9 script begin 5 6 7 10 script end 6 7 10 Serial register 31 shift 7 10 shift image to storage 7 10 shift mode verb 5 shift mode is 5 7 10 11 shift mode is alt 7 11 shift mode ism 7 10 11 shift mode ism alt 7 11 shift mode s 7 10 11 shift mode s alt 7 11 shift mode sm 7 10 11 shift mode sm alt 7 11 Shot noise 39 shutter close 7 11 shutter open 7 8 12 Single Image 13 Single parameter functions 4 Spaces 3 Spectral framing 36 Spectral image 19 Storage array 10 11 16 19 Subarrays 33 Subroutines 3 Syntax rules 3 summary 6 T V Tabs 3 TDI Time Delay Integration Panorama 14 Technical support 2 Thinned CCDs 38 Three color sequence 17 Time delay integration TDI 34 Time
18. wait for the trigger to be turned on loop begin 100 this allows exactly 99 interruptions expose_until_trig shutter is closed waiting for a trigger shutter open open the shutter and begin exposing expose_while_trig 0 GOOD EXPOSURE TIME Ey shutter close interruption 907 loop 1 _ 1 1 100 evening s worth of charge has accumulated pixel_readout 0 1024 1 1024 1 readout the entire CCD 1024x1024 307 pixel display 1024 1024 display the entire CCD script end 0 DO NOT CLEAR the CCD There is one problem If there have only been a half dozen interruptions how do you finish the readout The best way is to turn the switch off which closes the shutter put on a lens cap and toggle the switch about a hundred more times A somewhat riskier method would be to e Turn the switch off thus closing the shutter e Use the application to ABORT this script which shouldn t erase the image Run the next script script_begin FINISH READOUT OF A 1024x1024 CCD ef shutter_close just to make sure E clear serial 100 DO NOT clear the parallel register shift mode ism do all shifting in MPP mode pixel readout 0 1024 1 1024 1 readout the entire CCD 1024x1024 pixel_display 1024 1024 display the entire CCD script end 0 This last script needs to be typed into its own file since everything after the s
19. 1 peri Introduction Description The Advanced Camera Operation Manual includes e Imager Control Language ICL Rules of syntax ASCI II command set and example scripts e Advanced CCD Theory Background theory for advanced ICL users Most Roper Scientific cameras use an application programming interface called PVCAM Programmable Virtual Camera Access Method PVCAM is a custom ANSI C library of camera control and data acquisition functions Full function imaging packages access PVCAM These full function packages offer the camera control adequate for most users ICL is a PVCAM option library that allows users to write low level ASCI II command scripts for specialized applications The scripts which can be written in any text editor are then loaded through an ICL compatible full function imaging package into the ICL option library then through PVCAM to the camera interface ICL Script Full Function Imaging Package ICL Compatible Custom Software Application Software To run ICL scripts you must be running a full function imaging package that is ICL compatible You must also have installed the ICL and PVCAM files that are appropriate for your camera and interface PVCAM and ICL files are located on the Host Connectivity Kit HCK diskette Installation instructions for these files are covered in your camera system s Software Guide Roper Scientific Customer Service If you have a
20. CCDs 38 Charge coupled device CCD cont time delay integration TDI 34 clear count 7 clear first 8 clear parallel 7 8 clear serial 7 clear until trig 7 8 10 Commas 4 6 Comments 3 Conditional statements 3 contin clear 10 Cooling CCD 37 40 Customer Service 2 D G Dark current 29 in CCD cooling 37 operation 40 noise 40 Dec value 6 Decoding 27 Display 6 Display verbs 6 Down converters 38 Error codes 20 Example scripts 13 exp time 8 expose 7 8 expose until trig 7 8 expose while trig 7 8 Fiberoptic coupled CCD 39 flash 7 8 flash time 8 Form feeds 3 Frame transfer device 35 3 color sequence 17 high speed spectroscopy 19 readout variations 36 shift modes 10 11 Full frame CCD 35 Full well capacity 30 Function syntax 6 Functions multiple parameter 4 single parameter 4 43 H L Help camera 2 High speed framing 36 High speed spectroscopy 19 ICL scripting functions 21 Image array 10 15 16 19 35 36 Interline transfer device 36 Intermittent exposure 18 Inverted operation See MPP operation Jumps 3 Line feeds 3 loop begin 6 7 9 loop count 9 loop end 6 7 9 M P Man pages 21 Marconi CCD37 10 15 16 17 19 Metachrome II 38 MPP 5 7 8 10 11 18 40 Multi Pinned Phase operation 40 Multiple parameter functions 4 Noise sources 39 tradeoffs 40 number of lines 10 Numeric
21. DESCRIPTION RETURN VALUE SEE ALSO NOTES Class 101 ICL pl_exp_display_script 101 pl exp display script lists the display rectangles boolean pl exp display script int16 hcam icl disp ptr user disp array void ptr pixel stream This function can only be called after p1 exp setup script lt further processes the script that was loaded during pl exp setup script Users must pass in a structure that has at least num rects elements nium rects is passed back from pl exp setup script This function then fills that structure with the x and y sizes for every display rectangle as well as that rectangle s offset into the pixel stream which is why the allocated data collection pointer must be passed in TRUE for success FALSE for a failure Failure sets pl error code pl exp setup script 101 The script disp ptr is defined in pv icl h typedef struct ONE IMAGE DISPLAY FOR SCRIPTING 0 516 x image width to display in pixels unsl6 y image height to display in pixels void ptr disp addr starting address for this image icl disp type PV PTR DECL icl disp ptr The list of rectangles is unrolled from inside the looping constructs so users are presented with a simple linear list disp_addr is the starting address for the data for this rectangle based on the fact that all the data is put into the address pixel_stream In other words the address of the first rectangle is exactly
22. Definitions cccccccscccesecesscesscecssscecssecescceessecssceeessecesssessecesseecaeeesececsaeeesseecsseeesaees 7 NN E 13 Operthe Shutter E eras 13 Single Tima ge aaaea iai entea ier E 13 TDI Time Delay Integration Panorama sese 14 Ratio Imaging 2 Frame Ratio n nen nnns 15 Ratio Imaging Multi Frame Ratio sese eene eene 16 8 Color Sequ nce i ih se ee aae ia ef Her eh avertas 17 Intermittent Exposure iere eden n n Te ihi eee ir en end 18 High Speed Spectroscopy nete E divine dio e eae deve ated 19 Error Codes nasi ta Eee eei cero d onte ei bae beet 20 e eo ot e te e o ha ee bm et es 21 pl exp display seript 101 iones tete e e ett rre reget rit rie 21 pl expanit Seript 101 eee niter te nn orem eA ee eee tee edit erre es 22 pl exp listerr Script 101 antecedente metet mte be ecrire das 23 pl exp setup script 101 ene tiae ies 24 plexp start Senpt T10T d iaen e rte ede Ae er thee 25 pl exp uninit script 101 aopn aineena te brc tee ete eias 26 benc M 27 Decoding th inet butt bee pet bei n fige 27 Image Display At e e nde e aa dte e teh edes 27 iii Chapter 3 Advanced CCD Theory UGH ON iis 5 ete ed e tee er eee
23. NEVEN LOOP C101 ICL BIN TOO LARG C101 TOO C101 ICL DISPLAY SMAL C101 ICL DISPLAY LARG C101 ICL NO FRAME XFR C101 ICL NO MPP C101 ICL TOO COMPLEX 20 Advanced Camera Operation Manual ICL OPTION LIBRARY unknown error the script library not initialized the script library initialized script begin command was not seen text ended before script end instruction script instruction not correctly read opening parenthesis not present illegal character or symbol unexpected comma unexpected numeric parameter comma needed unexpected closing parenthesis extra comma semicolon missing from this instruction instruction has too many parameters instruction doesn t have enough parameters argument must be greater than zero argument must be 65 535 or less argument is invalid or illegal loops are nested too deeply too many loop end instructions loop begin commands don t match loop end readout s binning exceeds its size readout region does not fit on the CCD displayed data is less than the collected data displayed data is more than the collected data camera doesn t have a separate storage array camera does not allow MPP mode script exceeds available program memory Man Pages This section contains the Man Page descriptions for the six ICL scripting functions included in the library These functions are intended for use by application programmers only PVCAM NAME SYNOPSIS
24. al hardware This function compiles the script into a form that is appropriate for control ling hcam During that compilation it determines how many pixels will be collected The total number of bytes is returned in stream size and the user must allocate a p ixel streamarray of at least this size before running the script see pl exp start script During compilation the scripts display functions are also examined These functions specify how the resulting data is decomposed into individual images After this function has successfully returned the caller is assured that the script is accepted and properly processed the corresponding instructions have been transmitted to the camera which is now ready to go and the display instructions have been processed Data collection may now start by calling pl exp start script function TRUE for success FALSE for a failure Failure sets pl error code pl exp start script 101 pl exp abort 0 pl exp check status 0 Most of the complexity of this function is contained in the scripting language Read this manual for a more complete description of this function 24 Advanced Camera Operation Manual SYNOPSIS DESCRIPTION RETURN VALUE SEE ALSO NOTES Class 101 ICL pl_exp_start_script 101 pl exp start script begin exposing return immediately boolean pl exp start script intl6 hcam void ptr pixel stream hcam must specify a CCD camera that has be
25. al loops CCD A amp C make sure CCD is cleared clear until the experiment is ready CCD B amp D expose with this filter X takes 1 23 msec shift image under mask A CCD C amp E READOUT move REGION 1 up to serial register 51 52 of 300 400 is 101 total pixels actual size of the region REGION 2 is at the serial reg Xf move REGION 3 up to the serial regist leave CCD in continuous clear mode pod NOTE The CCD37 10 has a 512x512 image array but a 512x544 storage array Discard 5432 rows to move region 1 to the serial register 16 Advanced Camera Operation Manual 3 Color Sequence In this setup the target is illuminated by three filtered lights Each light can be switched on and off almost instantaneously in less than a millisecond There is a small amount of camera triggered hardware logic that coordinates the hardware with the exposure All lights are turned off when the Shutter Closed Output pin is on The experiment resets and starts again when the Shutter Open Output pin goes high and the first light turns on Then when the camera s Trigger Waiting Output pin goes high the experiment switches to the next light cycling red green blue The trigger port is being jumpered into itself In other words the Trigger Waiting Output is jumpered back into the Trigger Level Input The Trigger Invert Level Input is jumpered to Ground The final result is that in the script below the camera begi
26. al register is along one side of the parallel register perpendicular to the pixel columns The serial register is itself a one dimensional CCD It may be masked so that incident photons cannot create charge Many CCD formats and aspect ratios are available the choice of CCD is dictated by the application When a CCD imager is exposed to light charge accumulates in the potential wells of the parallel register Charge can accumulate over an extended period of time The total amount of charge is proportional to the product of the light intensity and the exposure time A charge accumulation is often called an integration The complete charge pattern corresponds to the focused image Chapter 3 Advanced CCD Theory 31 CCD Readout standard CCD readout sequence is shown in CCD Readout After an integration a programmed sequence of changing gate potentials causes all charge packets stored in the parallel register to be shifted one pixel towards the serial register the first charge packet in each column is shifted into the serial register Once in the serial register charge packets are individually shifted toward the output amplifier The output amplifier produces a signal proportional to the charge in each packet After the serial register is emptied of charge a second row of charge packets is shifted in from the parallel register The process continues until all charge has been shifted out of the parallel register CCD Readout
27. close pixel_readout 0 1317 1 1035 1 ps pixel display 1317 1035 Jo script_end 1 gx JE good precaution who knows what state it s in clear out any residual charge might as well clear this out too START TAKING THE IMAGE expose for 200 milliseconds DONE TAKING THE IMAGE readout the entire CCD display the entire CCD leave the CCD in continuous clear mode Chapter 2 ICL E d S A Ay 13 TDI Time Delay Integration Panorama This script is written for use with a Kodak 1400 CCD serial size 1317 parallel size 1035 The camera is attached to a telescope pointing straight up The camera s external trigger port is connected to a synchronized time source that provides a pulse every few seconds The pulse timing is closely coordinated with the image size so the rotation of the earth moves the image on the CCD by exactly one parallel row width 6 8 microns for each pulse Therefore for every pulse one row is readout and the other rows are shifted over following the moving image This script uses the setup to collect a single panoramic image 10 000 rows wide reading 1 row at a time 8965 times and finishing with a final clean up readout of 1035 rows The CCD reaches a steady state exposure duration during the middle of the panorama but the beginning and ending few lines are exposed for less time Exposure time is progressively less for the first and last 1035 rows of the
28. compiler that the script program is now finished Any text that occurs after this instruction is ignored If the parameter contin 1 camera remains in continuous clear mode This indefinitely cycles the CCD in a shift and eliminate charge loop similar to the clear until trig instruction Since this actively cycles power through the CCD it also generates heat within the CCD This may be a problem in some cases particularly if the camera is run near the low temperature limit Continuous clearing occurs until a new script or exposure is started an abort is sent or until the camera hardware is reset or turned off Other commands to the camera such as altering the speed setting also cancel continuous clearing contin clear must be either 0 or 1 shift number of lines This function shifts the number o linesrows of data in the parallel direction using the current shift mode Depending on the shift mode in use this may or may not shift the entire parallel register it may shift only the storage array shift the rows either forward or backward depending on the setting of the ALT shift modes or use MPP mode for the clocking The serial register is cleared during the shift operation so any charge dumped into the serial register is eliminated The two most common cases are described below shift mode isor shift mode 0 these two modes the entire parallel register is being moved Issuing the instructions shift 3 move
29. cript end instruction including that second script is treated as a comment 18 Advanced Camera Operation Manual High Speed Spectroscopy This script uses a frame transfer device the CCD37 10 CCD to perform high speed spectroscopy It collects a spectral image in the image array and bins that image down to a single line as it shifts it into the storage area THIS REQUIRES A FACTORY MODIFICATION TO THE CAMERA SEE BELOW The camera immediately performs another exposure bins it etc A total of 544 binned spectra are accumulated in the storage array then read out Although the CCD37 10 image array is 512x512 the storage array is 512x544 Each spectral line has a total exposure time of about 1 23 milliseconds so this gives 2 3 of a second of continuous high speed spectral monitoring with nearly a millisecond time resolution script begin shutter open 1 clear_parallel 2 this clears both image and storage 1 compensate for the first exposure time loop_begin 544 LOOP FOR EACH SPECTRUM EACH ROW IN STORAGE expose 0 total exposure time 0 1 23 milliseconds shift mode s shift the storage array only QA shift 1 move storage down 1 line to make way for zy shift_mode_s_alt custom setting shift IMAGE ARRAY ONLY shift 512 bin entire image array into top of storage NOTE this shift takes 1 23 milliseconds
30. d by interface states at the silicon silicon dioxide interface just below the parallel gate structure In MPP mode this dark current component is significantly reduced by biasing all of the parallel register gates into inversion However this causes the potential wells essential for operation to disappear allowing charge to spread up and down columns Efficient CCD action can be ensured by processing CCDs with a built in potential step that restores the potential wells when the parallel gates are biased at the same voltage Only CCDs thus processed can be operated in inverted mode Tradeoffs Ina given situation the available light level determines the integration time required to arrive at an acceptable SNR Acceptable SNRs vary with the application the tradeoffs between light level and integration time must be considered for each circumstance When the light level is high enough that photon statistics are the dominant source of noise preamplifier noise and dark current are not relevant The CCD data are said to be photon noise limited Under low light conditions where preamplifier noise exceeds photon noise the CCD data are said to be preamplifier noise limited When long integration times are used it is important to ensure that the noise from dark current does not exceed preamplifier or photonic noise from the signal Two examples give some insight into the tradeoffs required to maximize the SNR e Solar astronomy is a typical high li
31. delay integration panorama 14 Trigger port 8 14 17 TTL compatible signal 8 Warranties cont Underscores 6 one year i Unnested comments 3 owner s manual and troubleshooting ii Verbs 4 sealed chamber i as Subroutines 5 shutter i Display 6 software i looping 5 vacuum integrity i Shift 5 x ray detector i syntax 6 your responsibility ii W Z Whitespace 3 6 x y 9 Warranties i image intensifier detector i Index 45 ROPER SCIENTIFIC PHOTOMETRICS BENELUX FRANCE GERMANY JAPAN Roper Scientific BV Roper Scientific SARL Roper Scientific GmbH Nipon Roper K K D S Tuijnmanweg 10 2 1 Petite Montagne Sud Rosenheimer Landstr 87 D 10E 1 3 Nakase 4131 PN VIANEN Netherlands 4 rue de l Oisans C E 1702 D 85521 Ottobrunn Germany Mihama ku Chiba shi tel 31 347 324989 91017 Evry Cedex France tel 49 89 660 779 3 Japan 261 8501 fax 31 347 324979 tel 33 160 86 03 65 fax 49 89 660 779 50 tel 81 43 274 8022 email mailto roperscientific com fax 33 160 86 07 09 email mail roperscientific de fax 81 43 274 8023 email princeton instruments wanadoo fr email sales roper co jp USA USA Roper Scientific Arizona Roper Scientific New Jersey 3440 East Britannia Drive 3660 Quakerbridge Road Tucson Arizona 85706 Trenton New Jersey 08619 tel 520 889 9933 tel 609 587 9797 fax 520 295 0299 fax 609 587 1970 email cservice roperscientific com email techsupport roperscientific com 57 039 001 Re
32. ding Decoding the ICL Image Display Decoding defined as decoding the pixel stream to display one or more images must be simple enough to easily use yet powerful enough to display most experiments To satisfy both needs the scripts can contain any number of pixel display statements Each of these statements must specify a rectangular array of pixels to be decoded and displayed In addition these instructions can be contained inside of loops making them much more powerful and flexible To decode the ICL the scripting functions process whitespace and the following commands script_begin loop begin loop count pixel display x y loop end script end contin clear Particular attention is paid to processing display commands inside of loops and loops inside of loops loop nesting Once the script has been processed through the call to pl exp setup script all display instructions have been examined and recorded Application programmers can obtain the total number to display from thepl exp setup script command More detailed information is available from thepl exp display script command The image display method depends on the application You should perform the extraction and display tasks using the same method you are currently using to process the pixel stream and display images with conventional PVCAM In other words if you already have a working application you need to apply the same techniques used in that app
33. e incoming data TRUE for success FALSE for a failure Failure sets pl error code pl exp setup script 101 pl exp abort 0 pl exp check status 0 This is programmed as macro call pl exp start seq This script function exists to provide a complete and coherent conceptual model for the sequence style exposure functions From the API level it should always appear that an exposure style is self contained and complete and that each exposure style is completely independent from every other exposure style Underneath the API though code will be reused as needed Chapter 2 ICL 25 SYNOPSIS DESCRIPTION RETURN VALUE SEE ALSO NOTES Class 101 ICL pl_exp_uninit_script 101 pl exp uninit script unitialize the scripting library boolean pl exp uninit script void This function undoes the preparations done by pl exp init script After executing this function scripting functions may no longer be called TRUE for success FALSE for a failure Failure sets pl error code pl pvcam init 2 pl pvcam uninit 2 pl exp init script 101 This function must be explicitly called before calling p1 pvcam uninit You must also uninitialize the Class library pl exp uninit seq whenever you call pl exp uninit script Order is not important You may call either function first but both of them need to be performed before calling pl pvcam uninit 26 Advanced Camera Operation Manual Deco
34. el shifting mode that shifts the entire parallel register This mode can only be used on CCDs that support MPP clocking If this mode is used on a non MPP CCD the script compiler generates an error and fails In addition to using MPP clocking this function uses an alternate shifting mode see shift Unless an alternate shifting was loaded at the factory this mode is loaded with a default value identical to shift mode ism shift mode s Shift Storage This parallel shifting mode shifts only the storage array on a frame transfer CCD This mode can only be used on frame transfer CCDs If this mode is used on a non frame transfer CCD the script compiler generates an error and fails This function uses the normal clocking method that is usually equivalent to MPP off For CCDs that require MPP clocking the clocking method is MPP on shift mode s alt Shift Storage Alternate This parallel shifting mode shifts only the storage array on a frame transfer CCD This mode can only be used on frame transfer CCDs If this mode is used on a non frame transfer CCD the script compiler generates an error and fails This clocking is equivalent to MPP off except for CCDs that require MPP clocking In this case the clocking would be equivalent to MPP on In addition to the MPP style of shifting this function uses an alternate shifting mode see shi t Unless an alternate shifting was loaded at the factory this mode is loaded with a default value identical
35. en successfully opened by PVCAM This function is the companion function to pl exp setup script pl exp setup script must be called first to define the exposure and program this information into the camera After that pl exp start script may be called one or more times Each time it will trigger the script to begin executing from the start and then immediately return Since a script may have been aborted in the middle leaving the camera in an unknown state well written scripts will usually force the camera to a known state at the start of the script Exposure progress is monitored through p1 exp check status The next script can be started as soon as the readout is finished or an abort is performed pl exp abort The user must allocate pixel stream an appropriately sized memory buffer for data collection The buffer must be at least stream size bytes large where stream sizeisthe value returned from pl exp setup script In addition this memory needs to be page locked or similarly protected on virtual memory systems These requirements are system specific There is a special case for users who want to use their own frame grabber with an appropriately equipped camera If a null pointer is passed in for pixel stream pl exp start script willassume that the user is routing the data to a frame grabber or other device under user control Under those conditions pl exp start script willinitiate the exposure but will not attempt to handl
36. eters Arguments ICL ICL scripts can be written in any text editor Save the script as a text file then download through an ICL compatible imaging package This chapter includes e Script syntax e Function descriptions e Example scripts The basic rules of syntax are e Carriage returns line feeds form feeds tabs spaces and comments are treated as generic whitespace used to separate language elements This convention increases compatibility between operating systems and helps with editors that have different end of line conditions and tab expansions e There is no main program subroutines jumps calls conditional statements or branching e Braces are not allowed e All numeric values must be typed exactly Numeric and parenthetical expressions are illegal Whitespace includes a single occurrence or any combination of the following space carriage return line feed form feed tab and unnested comment characters Whitespace is not required Once the characters are seen you may insert any desired comments until the closing appears However you cannot nest comments The first ends the comment A second used before the ending has no effect while an additional will generate an error Approximately half of the script functions have no parameters The function must be followed by opening and closing parentheses with no parameters inside the parentheses Whitespace inside the parentheses is acceptable
37. extended with the use of a light emitting phosphor called a down converter A down converter absorbs light in the ultraviolet range of the spectrum and re emits it in the visible range CCD with a Down Converter demonstrates the use of the phosphor down converter Metachrome II in conjunction with a front illuminated CCD A CCD with a Down Converter 120 450 nm light 400 1000 nm light Phosphor Polysilicon gate Silicon dioxide Epitaxial silicon Bulk silicon _ 560 nm emission Oe eS The phosphor absorbs photons with short wavelengths and emits photons with a 560 nm wavelength These photons pass through the polysilicon gates into the photon sensitive region of the CCD The down converter is transparent between 400 and 1000 nm so CCD performance is not affected at these longer wavelengths Down converters exhibit very high quantum efficiency and when properly processed and applied to CCDs can produce a significant improvement in UV sensitivity 38 Advanced Camera Operation Manual Fiberoptics Sources of Noise Photon Noise Preamplifier Noise In most applications the CCD is illuminated by light from an imaging source such as a telescope spectrograph or microscope There is a class of applications however in which coherent fiberoptic bundles can be used in place of imaging optics A fiberoptic bundle comprises millions of glass fiber strands each of wh
38. first must be either 0 or 1 flash flash time This function activates the flash circuit a set of pins on the trigger port of many PVCAM cameras and continues applying power for flash_t ime milliseconds In some cases this may be used to activate devices connected to the camera such as an illuminator or filter wheel although the flash signal differs from camera to camera and is often not a TTL compatible signal For more information concerning the pinouts and electrical specifications of the trigger port refer to your camera s User Manual f1ash time must be between 1 and 65 535 inclusive 8 Advanced Camera Operation Manual loop_begin loop_count This function allows looping within a script A loop_count specifies the number of times to perform the loop All instructions between the loop_begin and matching loop_end commands are executed exactly loop_count times Loops may be nested up to 16 deep Note that indentation of a script s source code may improve readability but it does not alter the loop nesting in any way 1oop count must be between 1 and 65 535 inclusive loop end This function defines the end of loop and allows looping within a script This command must be matched with a 1 begin command the 1oop begin command must appear first Loops can be nested pixel display x y This function indicates that camera output is decoded for display on a monitor The application software takes the next x y pixels
39. for transportation and insurance charges is described above Sealed Chamber Integrity Warranty Roper Scientific warrants the sealed chamber integrity of all our products for a period of twenty four 24 months Open chamber products carry no warranty to the CCD imaging device expressed or implied Vacuum Integrity Warranty Roper Scientific warrants the vacuum integrity of all our products for a period of twenty four 24 months during which we guarantee the detector head will maintain the factory set operating temperature without the requirement for customer pumping Image Intensifier Detector Warranty All image intensifiers by nature are susceptible to Phosphor and or Photocathode burn physical damage when exposed to high intensity light Roper Scientific warrants with the exception of an image intensifier that is found to have a Phosphor and or Photocathode burn damage which carries no warranty expressed or implied all image intensified products for a period of 1 year after the date of the original invoice See the Limited One 1 year warranty terms and conditions above X Ray Detector Warranty Roper Scientific warrants with the exception of the CCD imaging device and fiber optic assembly damaged due to x ray which carry no warranty expressed or implied all x ray products for a period of 1 year after the date of the original invoice See the Limited One 1 year warranty terms and conditions above Software Warranty Rope
40. ght level CCD application For this application it is important to detect small fluctuations in intensity over the area of the sun as a function of time Because the light source is very bright a slow scan CCD camera always operates under photon noise limited conditions e Low light level conditions such as those encountered in fluorescence microscopy present a different problem For this application the photon flux is typically low and the excitation exposure must be kept short to avoid bleaching CCD sensitivity and preamplifier noise are extremely important If the CCD has a preamplifier noise of 10 electrons the image data are preamplifier noise limited when the number of photoelectrons in a pixel is less than 100 For signals above 100 electrons the data are photon noise limited 40 Advanced Camera Operation Manual Additional following articles provide more information on CCDs and their Readin g applications Aikens Richard S Charge Coupled Devices for Quantitative Electronic Imaging Tucson Arizona Photometrics Ltd 1991 Aikens Richard S Patrick M Epperson and M Bonner Denton Techniques for Operating Charge Coupled Devices CCD s in Very High Speed Framing Mode Proceedings of the Society of Photo Optical Instrumentation Engineers 501 1984 Dereniak E L and Crowe D Optical Radiation Detectors New York John Wiley and Sons 1984 Janesick James and Morley Blouke Sky on a Chip The Fabulou
41. gister and using only a small region as the image array A scene is focused on the image array and a high speed shutter or strobe light is used to time the exposure After each exposure charge from the image array is quickly shifted under the mask and a new image can be acquired Once the parallel register is filled with images it is read out Because fewer rows are clocked to shift the image array into storage this mode works much faster than standard frame transfer The high speed framing rate need not be constant but may be varied in response to the needs of the observation being made High speed spectra of a decaying phosphor for example may be obtained with decreasing time resolution in response to the exponential decay time of the emitted light Spectral Framing Ina mode particularly suited for spectroscopy the CCD is masked so that only a single row of the parallel register is exposed In this mode one dimensional line images can be acquired at a very high speed until the parallel register is filled up Spectral framing CCDs are used in time resolved spectroscopy An observation could consist of hundreds of individual spectra distributed over time The CCD clocks are controlled by computer so non linear time bases are possible Interline Transfer The interline transfer CCD has a parallel register that has been subdivided so that the masked storage area fits between columns of exposed pixels The electronic image accumulates in
42. he visible spectrum In crystalline silicon each atom is covalently bonded to its neighbors Incident photons that penetrate the lattice can break these bonds and generate electron hole pairs Silicon becomes transparent at 1000 1100 nm and is opaque to light at wavelengths shorter than 400 nm The photon produced electronic charge is proportional to the incident light between these wavelength limits However charge can be created by other energy sources High energy particles x rays and cosmic rays can break many thousands of bonds Excessive exposure can damage the crystal lattice Bonds can also be broken by thermal agitation The rate of electron hole pair generation due to thermal energy is dependent on temperature and can be reduced arbitrarily through cooling The unwanted charge produced by thermal agitation is called dark current because it is produced in the absence of light To measure the electronic charge produced by incident photons there must be a means of collecting the charge The figure A Potential Well illustrates the concept A Potential Well Incoming light Electrical connection d Polysilicon gate Silicon dioxide Silicon Potential well 29 Charge Transfer A thin layer of silicon dioxide is grown on a section of silicon and a conductive gate structure is applied over the oxide Applying a positive electrical potential to the gate creates a depletion
43. ich acts as an individual light pipe Each strand has a glass cladding that isolates it from neighboring strands to prevent crosstalk The optical fibers are carefully stacked and fused together under heat and pressure to form a solid rigid coherent optical transmission element The fiber boules that are produced in this process may be reheated and drawn into fiber tapers to meet the needs of specific applications Fiberoptic bundles may be twisted 180 to form image inverters A fiberoptic bundle may be bonded directly to a CCD effectively translating the image plane from the surface of the CCD out to the surface of the fiberoptic bundle The interface between the CCD and the fiberoptic must be made with great care to prevent damage to the delicate CCD surface Fiberoptic coupled CCDs are often used in conjunction with other optical devices such as image intensifiers and streak tubes equipped with matching fiberoptic outputs The high light collection efficiency provided by this approach warrants the additional complexity in fields such as radiography and electron microscopy where fiberoptic coupled CCDs are used to directly image phosphor screens electronic circuitry generates undesirable noise The effect of this noise on performance is described by the signal to noise ratio SNR Photon noise preamplifier noise and dark current noise are the three primary sources of noise in a CCD camera Photon noise also known as photonic or
44. iment swings in a filter relatively slowly sends a trigger pulse exposes for 100 milliseconds reads out then repeats H W A H W H W C H W D H W E CCD A CCD B CCD C CCD D CCD E experimental hardware goes to first position sends trigger pulse the first position runs for 100 milliseconds change filters about 40 milliseconds of delay the second position runs for 100 milliseconds change filters about 40 milliseconds of delay loop back to A prepare for exposure clear CCD wait for trigger expose for 100 milliseconds shift image to storage readout clear CCD wait for trigger expose for 100 milliseconds shift image to storage readout loop back to A The only problem is that you cannot use a signal to differentiate between CCD B and CCD D In the future camera hardware might be enhanced so that it produces a flash signal in CCD E Then you would use the enhancement to trigger step H W A script begin shutter open loop begin 200 JE clear parallel 4 clear until trig JE expose 100 ye shift_image_to_storage shift mode s shift 37 7 pixel_readout 300 101 1 21 1 pixel display 101 21 pixel readout 175 146 1 265 1 pixel display 146 265 shift 9 pixel readout 380 61 1 265 1 pixel display 61 265 loop end shutter close script end 1 SE SEQUENCE OF 100 IMAGE PAIRS 200 tot
45. ing immediately and continues exposing until a trigger signal arrives The script then continues with the next instruction During the exposure this applies voltage patterns to the CCD in either normal or MPP modes see expose As with the regular expose function this neither opens or closes the shutter For more information concerning the pinouts and electrical specifications of the trigger port refer to your camera s User Manual expose while trig clear first This function initiates a scripted version of the high level bulb mode exposure If clear_first is 1 this initially enters a continuous clearing mode exactly like clear until trig If clear_first is 0 the CCD exposes while it waits for the trigger In either case once the trigger arrives the CCD switches into an exposing mode either normal or MPP see expose for more information and continues exposing while the trigger signal is present As soon as the trigger ends the exposure stops and the script proceeds with the next instruction Note that this instruction is not redundant You can t use expose until trigin conjunction with other instructions such as clear until trig to duplicate the function of this trigger because a trigger signal stops the exposure with expose until trig while that same trigger signal starts and maintains expose while trig For more information concerning the pinouts and electrical specifications of the trigger port refer to your camera s User Manual clear
46. l frame Frame transfer AN Interline transfer VAN C Mask lt TE L a Image Storage Photosite lt 5 E Full Frame The standard full frame CCD imager has the simplest architecture The parallel register is used for photon exposure charge integration and charge transport A shutter is used to control the exposure and to block light during readout preventing charge smearing Frame Transfer The frame transfer CCD imager has a parallel register divided into two distinct areas The area at the far end of the parallel register is the image array where images are focused and integrated The other area the storage array is identical in size and is covered with an opaque mask to provide temporary storage for collected charge After the image array is exposed to light the entire electronic image is rapidly shifted to the storage array While the masked storage array is read the image array may integrate charge for the next image A frame transfer CCD imager can operate continuously without a shutter at a high rate Chapter 3 Advanced CCD Theory 35 There are some special adaptations of frame transfer devices shown in Frame Transfer Variations Frame Transfer Variations Standard frame transfer High speed framing Spectral framing Image Storage Image btoragd Image High Speed Framing The frame transfer concept can be extended to multiple frames by masking most of the parallel re
47. l specifications of the trigger port and how they relate to the shutter commands refer to your camera s User Manual shutter_open This function opens the camera shutter Once the shutter_open_delay time has passed this function continues on to the next script instruction See shutter close for more information For more information concerning the pinouts and electrical specifications of the trigger port and how they relate to the shutter commands refer to your camera s User Manual 12 Advanced Camera Operation Manual Example Scripts The eight example scripts in this section illustrate the rules and principles of ICL These scripts use every ICL function with the exception of shift mode sm and alt modes Electronic copies of the example scripts are in the ICL Example file on your HCK diskette Open the Shutter e Single Image e Time Delayed Integration Panorama e Imaging 2 Frame Ratio e Ratio Imaging Multi Frame Ratio e 3 Color Sequence e Intermittent Exposure e High Speed Spectroscopy Open the Shutter This script opens the camera shutter and leaves it open script_begin shutter open script end 0 Single Image This script is intended for use on a Kodak 1400 CCD serial size 1317 parallel size 1035 The script takes one full frame image and exits script begin shutter close jak clear parallel 2 clear serial 2 shutter open Jx expose 200 shutter_
48. lication to the image display See pl exp display script for more information Although the decoding and display must logically match the experimental setup the pixel display calls do not have to be in a one to one correspondence to the pixel readout calls The example scripts see the Example Scripts section illustrate situations where the readout and display are handled in very different ways inside the same script While the individual calls don t need to match the total number of pixels collected must match the total number of pixels being displayed The script processor pl exp setup script checks for this matching and generates error if there is any disagreement For more information concerning image display please consult the pl exp setup script and pl exp display script functions Chapter 2 ICL 27 This page intentionally left blank 28 Advanced Camera Operation Manual Chapter 3 Introduction Theory of Operation Potential Wells Advanced CCD Theory The charge coupled device CCD is the imager of choice for use in quantitative image acquisition systems This chapter familiarizes you with CCDs and the terminology used in describing them It also discusses CCD performance characteristics If these are already familiar topics you may still find this chapter useful as a refresher or a reference Most CCD imagers are made from silicon because of its properties when exposed to electromagnetic radiation in t
49. nd 0 IMPORTANT NOTE The command shift image to storage leaves the CCD set to shift mode readout was done without setting the proper shift mode the first exposure would read properly then read out 512 blank cleared lines leaving the image array untouched STEP 1 light is falling on the CCD Hj make sure the CCD is cleared clear until the experiment is ready STEP 4 take a 10 millisecond exposure F prepare to shift image into storage x shift image into top of storage STEP 5 2 a 10 ms exposure send flash signal x STEP 7 begin to close the shutter STEP 9 discard useless front of storage output both exposures in one command two 512 exposures 1024 rows Display first image xY Display second image Chapter 2 ICL 15 Ratio Imaging Multi Frame Ratio This script performs ratio imaging with the CCD37 10 CCD Only three small subregions are needed but to get a good statistical base for the images you must take a sequence of 100 identical exposures The subimage setup is CCD37 10 Image Array gt F 1 21 s2 p2 HHH lt region 3 380 300 440 390 THHE THHHHE lt region 2 175 26 320 290 THHHHE THHHHHE lt region 1 300 5 400 25 THHHHHE lt origin point 0 0 storage array These coordinates are INCLUSIVE 300 5 to 400 25 is a region of 101 serial columns and 21 parallel rows This exper
50. nic image read out from the CCD can be stored in a computer s memory Slow scan camera systems produce large quantities of data A 2000 x 2000 pixel CCD with a dynamic range of 20 000 1 requires eight megabytes of storage for each image Cooling the CCD reduces dark current to negligible levels allowing exposure times of up to hours in duration To achieve the highest possible sensitivity astronomers cool the CCD with liquid nitrogen eliminating the dark current produced by thermal generation at warmer temperatures High energy physicists on the other hand use CCDs in ultra high speed cameras to observe transient phenomena where dark current is not relevant A conventional shutter can be used to acquire exposures as brief as a few milliseconds or as long as an hour a microchannel plate image intensifier can be used to gate exposures of a few nanoseconds The resolution of a CCD camera is determined by the geometry of the specific CCD in use The CCD pixels set the limit of resolution In scientific grade CCDs a pixel varies in size from few micrometers up to 48 um the total imaging area is 1 to 24 cm2 In order to avoid aliasing moir or beat frequencies the magnification must be chosen so that at least two CCD pixels cover a desired resolution element in the image plane There is no dead space between pixels Charge generated by photons striking the CCD between pixels diffuses to the nearest potential well This is referred to as
51. ns exposing while it waits for a trigger then it triggers itself The Trigger Waiting Output pin has a high signal on it for about 7 microseconds When you see the high signal switch to the next light in the sequence red green blue red green blue etc of the pins are standard TTL voltage levels so the associated circuitry is fairly straightforward It is important to take this sequence as FAST as possible so use the CCD37 10 frame transfer CCD 512x512 image size 512x544 storage size and readout one exposure while exposing the next Although the script doesn t appear to expose at all aside from the first image the exposure time is equivalent to readout time shift time or about 140 1 2 141 milliseconds script begin shutter open clear 11 1 6 141 loop begin 50 loop_begin 3 shift_image_to_storage expose_until_trig shift 32 SIGNAL TO BEGIN THE EXPERIMENT clear CCD of charge 2 54 ms clear give proper exposure time for 1st image SEQUENCE OF 50 IMAGE TRIOS one trio 1 23 millisec leaves mode shift mode s CHANGE TO NEXT LIGHT 7 micro sec pulse discard excess in CCD37 10 storage array pixel readout 0 512 1 512 1 about 140 milli sec at a speed of 2 MHz pixel display 512 512 this has no effect on the expose timing loop end loop end shutter close sc
52. ny questions regarding your camera system contact Roper Scientific Customer Service When you call Roper Scientific please have your Roper Scientific job number or equipment serial numbers available Phone Fax E mail Mail 520 889 9933 between 8 00 a m and 5 p m MST 520 295 0299 cservice roperscientific com Roper Scientific 3440 East Britannia Drive Tucson Arizona 85706 In Europe you can reach Customer Service at BENELUX Phone Fax E mail Mail FRANCE Phone Fax E mail Mail GERMANY Phone Fax E mail Mail 31 347 324989 31 347 324979 mailto roperscientific com Roper Scientific BV Ir D S Tuijnmanweg 10 4131 PN VIANEN Netherlands 33 160 86 03 65 33 160 86 07 09 princeton instruments wanadoo fr Roper Scientific SARL Z I Petite Montagne Sud 4 rue de l Oisans 1702 91017 Evry Cedex France 49 89 660 779 3 49 89 660 779 50 mail roperscientific de Roper Scientific GmbH Rosenheimer Landstr 87 D 85521 Ottobrunn Germany In Japan you can reach Customer Service at Phone Fax E mail Mail 81 43 274 8022 81 43 274 8023 sales roper co jp Nipon Roper K K D 10E 1 3 Nakase Mihama ku Chiba shi Japan 261 8501 General product information and answers to some customer service questions can be found on our website http www roperscientific com 2 Advanced Camera Operation Manual Chapter 2 Introduction Rules of Syntax Whitespace Param
53. photon shot noise is a fundamental property of the quantum nature of light The total number of photons emitted by a steady source over any time interval varies according to a Poisson distribution The charge collected by a CCD exhibits the same Poisson distribution so that the noise is equal to the square root of the signal Photon noise is unavoidable and is always present in imaging systems it is simply the uncertainty in the data Preamplifier noise also called read noise is generated by the on chip output amplifier This noise can be reduced to a few electrons with careful choice of operating conditions Chapter 3 Advanced Theory 39 Dark Current Noise Dark current or thermally generated charge can be measured and subtracted from data but its noise component cannot be isolated Dark current noise is a particular concern in low light applications To reduce dark current CCDs can be chilled to approximately 50 C with thermoelectric cooling For extremely long exposures liquid nitrogen is used to cool the CCD to as low 120 At lower temperatures CCD performance may be degraded due to poor charge transfer efficiency MPP Operation Multi pinned phase MPP or inverted operation reduces the rate of dark current generation by a factor of 20 or more and thus relaxes CCD cooling requirements to the level where a thermoelectric cooler is sufficient for most applications Most of the dark current in a CCD is generate
54. pixel_stream If that rectangle was a 10x10 display the starting address of the second rectangle would be pixel stream 200 bytes Separate rectangle lists are kept for each hcam so multiple cameras and multiple users do not collide This reports on the state following the most recent call to pl exp setup script using this value of hcam A new call resets the list This function can be called after data collection has finished provided that a new call to pl_exp_setup_script isnot made in the mean time This function does not actually display data It only provides display parameters Chapter 2 ICL 21 SYNOPSIS DESCRIPTION RETURN VALUE SEE ALSO NOTES Class 101 ICL pl_exp_init_script 101 pl exp init script initialize the scripting library boolean pl exp init script void This function prepares and initializes the scripting option library It must be called once before any other scripting functions are called TRUE for success FALSE for a failure Failure sets pl error code pl pvcam init 2 pl pvcam uninit 2 pl exp uninit script 101 This function must be called explicitly after calling p1 pvcam init and before calling any other pl exp script function Scripting requires some of the functions in the Class 3 PVCAM library When scripting is initialized the Class 3 library must also be initialized pl exp init seq Order is not important so either the
55. pixels are digitized using a binning of s_bin Each subsequent row is then digitized in the same fashion for a total of p_size rows Finally if p binis greater than 1 parallel binning is also performed All parallel shifting is performed using the current parallel shifting mode In some cases the resulting readout makes no sense for example if a custom backward shift is used If any of the sizes are an uneven multiple of binning a smaller size that exactly fits the binning is used If the size is smaller than the binning size 4 binning 5 a fatal error is produced Chapter 2 ICL 9 You can use this function to stack several regions one after the other in the parallel direction However you cannot stack more than one region at a time in the serial direction s_offset may be zero All other parameters must be between 1 and 65 535 inclusive s_size and p_size must be at least as large as their corresponding s_binand p_bin Finally s_offset and s_size must be no larger than the CCD serial size script_begin This must be the first instruction in the script It signals that the script is starting now Any text that occurs before this instruction is ignored This allows you to put in an initial comment block that can be used to explain the purpose and operation of script programs This instruction automatically puts the CCD into shift_mode_is script_end contin_clear This must be the last instruction in a script It signals to the
56. pply to you 12 When contacting us for technical support or service assistance please refer to the factory of purchase contact your manufacturer s representative or reseller or visit our technical support page at www roperscientific com ii Advanced Camera Operation Manual Table of Contents Chapter Introduction IDES CHIP HON M 1 SOLEWATLO sit eh bs eas HR sev eon net Bi eeu dne CLER estie Paus ees der qon 2 Roper Scientific Customer Service nie eene diee ria aaa 2 Chapter 2 ICL Introduction zc etre e eret 3 aee idum ipie ob a intra a Ente ties 3 Whitespace eec anise Wii ohh teeta de e E d a D ete iere 3 Parameters Arguments neto tabe e reri ng poa sive ni de 3 Single Parameter Functions sse ee eene nnns 4 Multiple Parameter Functions see eee eee eene nennen 4 Verbs externae n Mc um cM E Md TT RULES Ns 4 Verbs as S broutines neatis iie e o eec veste dede eee o eti dee qos 5 Begin and Btid ied date e Aa ette Eie D ets 5 Looping Verbs zat en Ie eet aue e tete oes e eei dede 5 Shift Verbs e ear tei o bare 5 Display Verbs sinss eet ie et eed t efi Pn ih Bd ed 6 Syntax DUImttlaty a atas en tree eh e E Ete e re e Di Boa en ta e EE Pena 6 seul ole EUN TIN 6 WhitesSpaceu sone next niei thee te EO edited Eo Dro to edet ilo e 6 Function Syntaxis senem E et OU ONES E send 6 Readout Eigen Rs 6 Function
57. product to the Roper Scientific factory or at our option a factory authorized service center You are responsible for all transportation and insurance charges to return the product to the service center and Roper Scientific will be responsible for all transportation charges and insurance to return the product to you International customers should contact your local manufacturer s representative distributor for repair information and assistance or visit our technical support page at www roperscientific com Shutter Warranty Roper Scientific warrants the standard factory installed shutter of all our products that incorporate an integrated shutter for a period of twelve 12 months This warranty applies to the standard shutter installed in the camera system at the time of manufacture Non standard shutters SPR special product request shutters and third party shutter drive equipment carry no warranty expressed or implied Roper Scientific will supply at no cost to the customer up to one 1 replacement shutter during the warranty period Roper Scientific will at Roper Scientific s option either ship a ready to install shutter to the customer site for installation by the customer according to the instructions in the product User Manual or arrange with the customer to return the camera system or portion of the camera system to the factory or factory authorized service center for shutter replacement by a factory authorized agent Responsibility
58. r Scientific warrants all Roper Scientific manufactured software discs are free from defects in materials and workmanship under normal use for a period of one 1 year from date of original invoice Roper Scientific does not warrant that the function of the software will meet your requirements or that operation will be uninterrupted or error free You assume responsibility for selecting the software to achieve your intended results and for the use and results obtained from the software In addition during the 12 month limited warranty the original purchaser is also entitled to receive free version upgrades Version upgrades supplied free of charge will be in the form of a download from the Internet Those customers who do not have access to the Internet may obtain the version upgrades on a CD ROM from our factory for an incidental shipping and handling charge See Item 12 in the Your Responsibility section of this warranty for more information Owner s Manual and Troubleshooting You should read the owner s manual thoroughly before operating this product In the unlikely event that you should encounter operation difficulties the owner s manual should be consulted before calling the factory for support If you have consulted the owner s manual and the problem still persists please contact the appropriate factory for support See Item 12 in the Your Responsibility section of this warranty for more information Your Responsibility The above war
59. ranties are subject to the following conditions 1 You must retain your bill of sale invoice or provide other proof of purchase 2 You must notify the factory service center within the first thirty 30 days after you have taken delivery of a defective product or part With the exception of customers who claim a technical issue with the operation of the product or part all invoices must be paid in accordance with the terms of sale Failure to pay invoices when due may result in the interruption of your one 1 year limited warranty and or any other warranty expressed or implied All warranty service must be made by the factory or at our option an authorized service center 4 Before products or parts can be returned for service the customer must contact the factory and receive a return authorization number RMA Products or parts returned for service without a return authorization will be sent back freight collect 5 These warranties are effective only if purchased from the factory or one of our authorized manufacturer s representatives or distributors 6 Unless specified as part of the original purchase agreement Roper Scientific is not responsible for installation setup or disassembly at the customer s location 7 Warranties extend only to defects in materials or workmanship as limited above and do not extend to any product or parts which have been lost or discarded by you to damage to products or parts caused by misuse in viola
60. rge is accumulated from two or more rows before serial shifting begins With serial binning two or more charge packets are similarly accumulated in the output node before the charge is digitized and read out Binning is specified by a binning factor the number of pixels to be combined on the CCD The example shows 2 x 2 binning Any combination of parallel and serial binning factors is possible The default values of 1 provide no binning Chapter 3 Advanced CCD Theory 33 Binned Readout ZX A mm The CCD is exposed Charge in the parallel Charge is again shifted The summed charge is to light and a charge register is shifted once into the serial register shifted once into the pattern accumulates into the serial register The serial register con output node in the parallel register tains the summed charge AN ere Steps 4 and 6 are Steps 2 through 7 repeated until the entire are repeated until serial register is read out the entire parallel register is read out The summed charge The charge at the output is shifted again The node is collected output node contains for signal processing the charge from four pixels Time Delay Integration Time delay integration TDI is an integration and readout mode that allows the acquisition of long swaths of a moving image The figure Time Delay Integration on page 35 illustrates
61. ript end 1 SIGNAL EXPERIMENT END amp RESET leave the CCD in continuous clear mode Chapter 2 ICL TA p ny xy pA T 17 Intermittent Exposure This script takes a stellar image of a faint galaxy The observatory is located under the flight path of a local airport and incoming planes occasionally pass through the field of view The observatory has at least 30 seconds warning before a plane passes over so the camera needs a signal to close the shutter stop exposing temporarily then begin exposing again The camera supports MPP mode so the dark current can be drastically reduced during the several hour exposure A switch connected to the camera s trigger input pin controls when the shutter opens and closes The switch is simply an open close switch inserted between the ground and the trigger pin on the camera s trigger port When the switch is turned on the camera opens the shutter and exposes When the switch is turned off the shutter closes and the exposure waits The camera is still exposing but it has a closed shutter and minimal dark current script begin shutter close good precaution who knows what state it s in clear parallel 5 clear out any residual charge XJ clear_serial 2 might as well clear this out too shift_mode_ism force the CCD to shift and EXPOSE in MPP mode sa clear_until_trig
62. s CCD Sky and Telescope September 1987 Janesick et al 1989 Charge Coupled Device Pinning Technologies Proceedings of the Society of Photo Optical Instrumentation Engineers 1071 15 1989 Kristian Jerome and Morley Blouke Charge Coupled Devices in Astronomy Scientific American October 1982 Sweedler Jonathan V Robert B Bilhorn Patrick M Epperson Gary R Sims and M Bonner Denton High Performance Charge Transfer Device Detectors Analytical Chemistry 60 282A 1988 Chapter 3 Advanced CCD Theory 41 This page intentionally left blank 42 Advanced Camera Operation Manual Index 3 color sequence 17 Arguments parameters 3 ASCII name 6 Begin and End 5 Binning 33 Branching 3 Bulb mode exposure 8 C C generation 6 Calls 3 Camera help 2 repair 2 Carriage returns 3 Charge 29 Charge transfer 30 Charge transfer efficiency CTE 32 Charge coupled device CCD advanced CCD theory 29 architectures 35 binning 33 charge transfer 30 charge transfer efficiency CTE 32 cooling 37 40 dark current 29 40 down converters 38 fiber XE Fiberoptic coupled CCD optic coupled 39 frame transfer 35 full frame 35 full well capacity 30 high speed framing 36 interline transfer 36 operation 40 noise 39 parallel register 31 potential wells 29 quantum efficiency 37 readout sequence 32 serial register 31 spectral framing 36 subarrays 33 thinned
63. s the entire parallel register 3 rows closer to the serial register The far end of the parallel register is filled with zeros no charge The three rows closest to the serial register are dumped in to the serial register and cleared shift mode sor shift mode sm These two modes can only be performed on frame transfer devices Issuing the instruction shift 3 moves the storage array three rows closer to the serial register The far end of the storage array is filled with zero no charge The image array is completely unaffected it is often left exposing The three rows closest to the serial register are dumped into the serial register and cleared Please note that the a1ternate shift modes are usually loaded at the factory with settings that are identical to the normal modes You can request custom settings that allow backward shifting shift image only etc Also note that shifting is not useful for outputting pixels It is useful only for moving a region into position for readout Readout must be done through the pixel readout command number of lines must be between 1 and 65 535 inclusive shift image to storage This function can only be used on frame transfer devices It shifts the CCD s image array into the storage array and any data currently in the storage area is lost It is shifted into the serial register and the serial register is then cleared Although this operation could also be accomplished using appropriate combinations
64. signal when it is ready for the first image to be taken 4 Upon receipt of the TTL signal the camera exposes the first image and then stores it 5 The camera begins the second exposure Simultaneously it provides a flash signal see the PXL User Manual this closes the ground side of a 10mA 15VDC current source 6 Upon detection of the flash signal the experimental hardware switches off the primary lighting and turns on the secondary lighting 7 The camera finishes the exposure and turns off the flash signal It then begins to close the shutter 8 When the flash signal stops all lighting turns off too this compensates for the relatively slow mechanical shutter 9 The camera outputs data for both exposures This script takes two very fast exposures 10 milliseconds each with minimal delay between each exposure on the CCD37 10 shifting an image into storage takes less than 1 3 milliseconds The shutter is slower than the exposures A typical mechanical shutter requires 15 milliseconds to close To remove this effect lighting must be shut off as soon as the second exposure is finished It is assumed that the lights instantly drop to zero intensity Script begin shutter open clear parallel 2 clear until trig expose 10 shift mode is shift 512 flash 10 shutter close shift 32 pixel readout 0 512 1 1024 1 pixel display 512 512 pixel display 512 512 script e
65. the TDI principle A moving image is focused on an unshuttered CCD imager The parallel register is clocked in step with image motion so that charge packets always correspond to the same image region as they move across the parallel register Charge accumulates and signal strength increases as the pixels approach the serial register When pixels reach the serial register they are transferred out digitized and stored in the normal fashion The exposure time for each pixel is exactly the length of a full parallel shift sequence which is determined by the velocity of the scene Compared to a simple exposure TDI increases sensitivity in proportion to the number of rows in the parallel register Although the TDI technique was first used by astronomers to take images of passing star fields it has also been used to acquire swath images from airplanes and satellites and is very effective for inspecting articles on a moving conveyor belt TDI is normally used with scenes moving at a constant velocity but other variations are possible 34 Advanced Camera Operation Manual Time Delay Integration E CCD Three types of CCD imagers are used for quantitative electronic imaging CCD Architectures Architectures illustrates basic CCD structures that are in current use CCD Architectures Ful
66. the exposed area of the parallel register just as it does in the frame transfer CCD At readout the entire image is shifted under the interline mask The masked pixels are read out in a fashion similar to the full frame CCD To enhance the interline transfer CCD s sensitivity micro lenses are applied directly to the CCD s surface The micro lenses cover the entire pixel and part of the mask on either side of the pixel In this way the micro lenses help to focus light to the CCD s parallel register by funneling photons to active pixels rather than allowing them to bounce off of the masks 36 Advanced Camera Operation Manual CCD Camera Implementations Resolution Sensitivity To take advantage of the high performance a CCD has to offer special slow scan or still imaging cameras have been designed to operate at a significantly lower speed than conventional video cameras These cameras bring together several diverse technologies high performance signal processors solid state coolers precision digitizers and high speed digital controllers The benefits of slow scan readout are ultra low noise maximum CCD performance and photometric precision in the image data A precision analog processing circuit and analog to digital converter are employed to amplify and digitize the CCD output signal CCD readout may take from one tenth of a second up to several seconds as each pixel is digitized with up to 16 bit precision The digitized electro
67. tion of instructions furnished by us or to units which have had serial numbers removed altered defaced or rendered illegible 8 Atyour option after the warranty period has expired you may contact the factory for repair information and extended warranty plans 9 Physically damaged units or units that have been modified by a customer are not acceptable for repair in or out of warranty and will be returned as received 10 All warranties implied by state law or international laws including the implied warranties of merchantability and fitness for a particular purpose are expressly limited to the duration of the limited warranties set forth above With the exception of any warranties implied by state law or international laws as hereby limited the forgoing warranty is exclusive and in lieu of all other warranties guarantees agreements and similar obligations of manufacturer or seller with respect to the repair or replacement of any parts In no event shall Roper Scientific liability exceed the cost of the repair or replacement of the defective product or part 11 This warranty gives you specific legal rights and you may also have other rights that may vary from state to state and internationally from country to country Some states and countries do not allow limitations on how long an implied warranty lasts when an action may be brought or the exclusion or limitation of incidental or consequential damages so the above provisions may not a
68. to shift mode s shift mode sm Shift Storage MPP This parallel shifting mode shifts only the storage array on a frame transfer CCD This mode can be used on CCDs that support both MPP clocking and frame transfer If this mode is used on a non MPP or non frame transfer CCD the script compiler generates an error and fails shift mode sm alt Shift Storage MPP Alternate This parallel shifting mode shifts only the storage array on a frame transfer CCD This mode can be used only on CCDs that support both MPP clocking and frame transfer If this mode is used on a non MPP or non frame transfer CCD the script compiler generates an error and fails In addition to the MPP style of shifting this function uses an alternate shifting mode see shift Unless an alternate shifting was loaded at the factory this mode is loaded with a default value identical to shift mode sm shutter close This function closes the shutter Once the shutter close delay time has passed this function continues on to the next script instruction Since there is no default shutter position and if the shutter position is important to the current script set the shutter open or closed at the start of the script program Note that none of the other script instructions except for shutter open of course alters the shutter state Specifically none of the expose Chapter 2 ICL 11 commands affect the shutter For more information concerning the pinouts and electrica
69. ts at the head of a script without using comment delimiters Script end specifies that the script is finished transmit to the camera If Script end appears the script processor will not continue to the null terminating character at the end of the input string Use the following verbs for looping loop begin loop count loop end All instructions occurring between these two verbs are executed 1oop count times The mechanism that performs this communication is camera specific On most systems built in commands are used to perform looping However on some systems the instructions inside the loop may be duplicated 1oop count times You can nest loops to 16 deep For every 1oop begin function there must be one 1oop end instruction If you create a different number of loop begin and loop end it generates an error and the script fails A shift verb tells the camera to immediately shift one or more lines in the parallel register using the currently selected shifting mode A shift mode verb changes the current state of the camera and specifies the clocking method used during exposure MPP or normal The new state is implemented the next time that the shift verb is executed shift mode is shift mode is alt shift mode ism shift mode ism alt shift mode s shift mode s alt shift mode sm shift mode sm alt Note that script begin initializes the shift mode to shift mode is Chapter 2 ICL 5
70. ure Failure sets pl error code SEE ALSO pl exp setup script 101 NOTES Separate error lists are kept for each hcam so multiple cameras and multiple users will not collide This reports on the error state following the most recent call to pl exp setup script using this value of hcam A new call to pl exp setup script resets the error list Some errors indicate a problem with the entire program rather than a single line for example errors 10122 or 10123 In such a case the error will be listed as occurring at character 0 line 0 This indicates that while no single line is at fault there was an inconsistency in the program at large Chapter 2 ICL 23 SYNOPSIS DESCRIPTION RETURN VALUE SEE ALSO NOTES Class 101 ICL pl_exp_setup_script 101 pl_exp_setup_script process a script download instructions to the camera boolean pl exp setup script int16 hcam char const ptr script uns32 ptr stream size uns32 ptr num rects hcam must specify a CCD camera that has been successfully opened by PVCAM This function uses the input string script to create a control program for hcam The script controls all aspects of one or more exposures including clearing the CCD opening and closing the shutter shifting the parallel register or registers in the case of frame transfer CCDs and reading out the pixels The script is also capable of coordinating with external triggers and triggering extern
71. v C1
72. verb must be followed by parentheses and terminated by a semicolon e The number of parameters is fixed for each verb e Parameters must be hard coded numeric values containing only the characters 0 9 e Parameters must be separated by commas e Whitespace may be inserted between parenthesis commas parameters or verbs but not between verbs and opening parenthesis Readout Display Neither pixel_readout nor pixel display is mandatory but if one appears they must both appear The total number of pixels collected must match the total number of pixels displayed 6 Advanced Camera Operation Manual Function Definitions clear parallel clear count clear the entire parallel register clear count times Clear serial clear count clear the serial register clear count times clear until trig waits for a trigger clearing meanwhile expose exp time a timed delay while light falls on the CCD expose until trig allow light to fall on the CCD until a trigger pulse expose while trig clear first bulbmode expose while you hold the button flash flash time activate the flash circuit for flash time ms loop begin loop count loop control start a loop do it for loop count cycles loop end loop control bottom end of a loop pixel display x y instruction to application display this size image pixel readout s offset s size s bin p size p bin
73. which function is performed next Verb names are a mixture of lowercase text and underscore characters All verbs are followed by parentheses even if the verb does not require parameters There is no whitespace between the verb name and the opening parenthesis List parameters inside the parentheses and separate the parameters with commas Whitespace is allowed in the parameter list but is not required After the closing parenthesis add a semicolon See sample below verbl verb2 parameter verb3 parameter verb4 parameter parameter parameter whitespace verb5 You can use several verbs on a single line one verb per line several lines of whitespace or any combination of the above 4 Advanced Camera Operation Manual Verbs as Subroutines Begin and End Looping Verbs Shift Verbs You can think of verbs as camera functions or subroutines A single verb instruction such as flash or clear until trig can be expanded into a sequence of camera specific instructions Most verbs are directions for the camera to perform the function immediately using the current settings There are two commands required for every script if either command is missing the program sets an error code script_begin Script end contin clear Script begin specifies the start of the program Anything appearing before Script begin is considered whitespace and is ignored by the script processor Therefore you can insert commen
74. your camera s User Manual Please note that the current parallel shift is completed before the camera begins integrating expose exp time The CCD exposes for exp time milliseconds This command usually appears immediately after shutter open clear parallel Orclear until trig Note that exposing is not equivalent to merely waiting for the duration of the exposure time During an exposure voltage is applied to the CCD in a gridlike pattern to produce potential wells pixels and to keep the charge from drifting into adjacent cells On some CCDs this voltage may be applied in either normal or MPP mode The mode actually used for the exposure reflects the most recently set parallel shifting mode whether that mode was set to normal or MPP exp time may be set to zero although this instruction becomes a no operation under those conditions The exp time variable maintains full precision up to a value of 65 535 milliseconds After that point the program creates longer times through an internal loop counter that provides more precise timing than the scripting loop begin command Due to this mechanism some values may be rounded off to a nearby value for example prime numbers greater than 65 535 won t be exactly represented The maximum exposure length is 2 32 milliseconds about 49 days For more information on using exposure in conjunction with frame transfer consult your camera s User Manual expose until trig This function begins expos

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