SRI-500 User`s Manual
Contents
1. azimuth from 90 left of straight ahead to 45 right and 45 degrees of elevation above horizontal down to 45 below horizontal acquiring 200 points per vertical scan The line rate and turret speeds are set up to acquire one vertical line for every 20 encoder counts 0 45 degrees of turret rotation or 300 lines in total Acquire one or four scans The scan parameters are determined by int status elevationSpeed scanner 500 will acquire 500 vertical lines per second in next scan s int status azimuthSpeed scanner 10000 move turret at 10000 encoder counts second 225 degrees sec in next scan s Page 10 of 20 int azimuthStart 4000 corresponds to 90 degrees left of straight ahead 16000 to 16000 2pi 2pi int azimuthEnd 2000 corresponds to 45 degrees right unsigned elevationStart 1000 corresponds to 45 degrees above horizontal unsigned pointsPerLine 200 unsigned elevationResolution 10 separation of measurement points in vertical scan axis counts 10 will give 200 points in 2000 elevation encoder counts or 90 degrees status singleScan scanner azimuthStart azimuthEnd elevationStart pointsPerLine elevationResolution or status repeatingScan scanner azimuthStart numberOfLines elevationStart pointsPerLine elevationResolution 4 The singleScan command will position the turret to a position that will allow it to accelerate to constant speed spec2. bs A etas eae 6 4 3 2 ClOSeScaHlero5csv e eder eene etos ecce eu 6 4 4 SCANNING LOCATION AND SPEED COMMANDS ss ssssssssseessetsstesttsetetetssersttsstesstesseestesstsstesstesstessressresseeset 7 4 4 1 AZ UMUC S DO EE Z 4 4 2 elevatronSpeed iio deae ener OS AE I pen S Aap EEE 7 4 4 3 azemuthPoSTUl0 mp s ca a IURI NN d 4 5 MODE Ge T IP M EE 8 4 5 1 EE eet e CERCLE 4 5 2 ScanOnSoftwareTEIggef nueve eee eine eee eias tenen ee M aste de ee Mesa ptiredel amp 4 5 3 SCANNESL PLE GG hM c EE amp 4 5 4 ScanoOnHardwareTPlgger x eI OH EO eee a aera ee amp 4 5 5 BCANN ELS L SSD iis reo Eaa 9 4 5 6 EE 9 4 6 SCAN AND TURRET MOTION COMMANDS nennen innen nens etre tients entes reisen tentes entente inneren 10 4 6 1 singleScan repeatingSCamniu ede a ve eene tees bisce tio eee i eese eee tue 10 4 6 2 TATE SCAT EE EE Il 4 7 SCAN DATA ACQUISITION AND PROCESSING iiie setinin rea E Er E E 12 4 7 1 CreateSRIDacketBUILfer v i pegensuae ceto epo eem eret 12 457 2 deleteSRIpacketB iferiis s nsden xen DOR E EO UE RISGU UU RE IEEE 12 4 7 3 recervelmagePacoEGLd ugar eee rete esee ete teretes eet ee Sees cone ETE Sea 13 4 7 4 CLEACESRITMAGEBUL tg eere ege eise evade eene de eye dae eee eu EEE EEE 14 4 7 5 deleteSRIImageBuftEfer EE 15 4 7 6 addPacket TOoTtmadge o nets ele Mental ete tee de etpete oboe barely ertet tlg ud 15 4 8 DEMON
3. 85 Reflectance Lambertian Surface 500 feet Minimum Range 3 feet Laser Wavelength 905 nm Eye Safety Eye safe Average Laser Power lt 1mW Laser Interlock Vertical scan mirror encoder Laser Spot Divergence 2 millirad H x 0 5 millirad V Optical Aperture 2 x 8 5 Scan Motors Long life brushless DC Azimuth Accuracy Platform Relative 1 5 arc min Elevation Accuracy Platform Relative 1 arc min Range Gating Minimum and maximum range limits in increments of 12 5 feet from 3 to 500 feet Weight 33 Ib Power 50 W 12 28 VDC Environmental Enclosure IP65 NEMA 4 waterproof Operating Temperature 20 to 70 C shade 20 to 50 C direct sun Storage Temperature 40 to 85C Shock and Vibration 5G operating 10G survival Connectors Waterproof UV resistant power and ethernet Optical Head Sealed dry nitrogen filled Inertial Measurement Unit Option 6 Axis quartz accelerometer gyro AHRS system Image Stabilization Azimuth drift 0 05 sec Pitch roll drift 0 02 sec Pitch Roll Earth Vertical Attitude Accuracy Stationary 0 1 Maneuvering Vehicle 0 5 typical y Output Data Physical Data Interface 100 Base T Ethernet Application data rate 25 6 Mbit s at max scan rate Data Output Streaming scan packet data Latency 100 milliseconds maximum Scan Packet Packet Header Timestamp Inertial Velocity Change from Previous Scan End Inertial Azimuth Change From Previous Scan End Point Sample Data Range 0 1 inch resolution O to 6500 i
4. Acuity Technologies SRI 500 User s Manual Rev 1 5 October 3 2010 Acuity Technologies 3475 Edison Way Bldg P Menlo Park CA 94025 www acuitytx com Page 1 of 20 TABLE OF CONTENTS 1 2 3 4 BAS HAYA E 3 1 1 SCANNING OPERATION x oes ceret ica RR ee E ene Red ibit EO dede de e PS 3 1 2 USB AND MAINTENANGE EE 3 1 3 AZIMUTH MOTOR PATH PLANNING 5e fett bob ovo ERENNERT o o eius e ae 3 HARDWARE POWER UD 5 eren eee oe eran g ve ca ee eT Ne ERR PP ee EN eH eY NEEESE NEEN Fe ENG ree PSESE SESTRE EENES EYE CHER P REESE NE 4 2 1 POWER SIGNAE CONNECTION 5 3 xr GI eve E eed E Rn Abd DIE ADU ial ret es 4 SOFTWAREJINSTALLATIQON ei eee poen neo ee ee tetur oov eon DEER DEEN ae eres EEN 4 3 1 CD DIRECTORY STRUGTURE ere eed Eed MERERETUR ER Ie ee E TS ERT ERR 4 SALTO Ethernet Connectivity X usos ede ree e phe pa eee ele ne eee ep i e RR cet 4 3 2 SOFTWARE INSTALLATION UNDER X er idee EE ERE UA e EE EGER ECHTE XV Ce 5 3 3 SOFTWARE INSTALLATION UNDER LINUX eeeeeeeeeeeeeeeeeene enne nene en rhet netten rnnt tenter rese tenter rre t ennt erret ens 5 PROGRAMMING INTERFACE ees iet eo rope ea ee rh rh pae Ee ele eh Eh epo EENS Eege div cero Ee dg 5 4 1 OVERVIEW M ES 5 4 2 STATUS RETURN VALUES EE 5 4 3 COMMUNICATION LINK COMMANDS eese enne enne ea EEEE RESER AEEA erret tene enne tenen 6 4 3 1 Eeer eech tei e etate
5. STRATION CLIENT SOFTWARE csssccssscessssesccessevensecsssesensecsssevensecessevensscnsseeensecnsseeensecesesensesnnees 16 4 9 SRI S00 DATASHEET FOLLOWING PAGES eege ete eve ote eR ele geen 16 Page 2 of 20 1 Overview The SRI 500 Scanning Rangefinding Imager consists of a pulse laser rangefinder a turret mounted scanning mirror and a processor with Ethernet for SRI to client communications The SRI 500 operates by measuring the time difference between a transmitted laser pulse and a received laser pulse and deflecting a high speed mirror in azimuth and elevation to scan a field up to 130 by 600 degrees 1 1 Scanning Operation The SRI 500 acts as a scan data server for a client machine which communicates through a set of commands transmitted via Ethernet A scan is 1 to 30001 vertical lines of rangefinding data Each vertical line in a scan consists of 1 to 3001 range measurement points The SRI 500 acquires and transmits scan data in response to scanning commands transmitted to it from the client Vertical lines are actually slightly sloped depending on the horizontal and vertical scan speeds set by the client The maximum vertical scan rate is 500 lines per second Scan data comes from the SRI 500 in a UDP packet defined by ScanDataPacket Each 3D Range data sample is defined by a 16 bit range value two 16 bit angular direction values and 1 byte value for signal strength This can then be converted to Cartesian coordinates by clien
6. alid and whether it was transmitted and acknowledged successfully 4 2 Status Return Values enum StatusReturnValues eNoError 0 eScannerStateInvalid eScannerNotAvailable eInvalidCountRate eScannerBusy eInvalidAzimuth eInvalidNumberOfLines eInvalidElevationStart eInvalidInvalidElevationResolution eInvalidAzimuthDirection eInvalidNumberOfScans eScanPacketIDDoesNotPackSRIImageID Page 5 of 20 4 3 Communication Link Commands 4 3 1 OpenScanner SRI500 scanner OpenScanner int timeout int scannerIndex 0 Returns a handle to the scanner communication data or an error code if connection with the scanner is unsuccessful scannerIndex For systems with only a single scanner this parameter should be set to 0 Additional scanners are referenced by scannerIndex 1 2 3 etc timeout the time in seconds attempt open command before failing 4 3 2 CloseScanner int status CloseScanner SRI500 scanner Frees scanner resources and closes the scanner connection scanner Handle to the scanner instances as returned by OpenScanner Page 6 of 20 4 4 Scanning Location and Speed Commands The speeds of the scans and the scan start and stop vertical and horizontal locations are based on the internal scanning motor encoder counts The vertical scan resolution 1s 8000 counts per 360 degrees of optical scan angle 16000 counts per elevation motor rotation The horizontal resolution is 16000 counts per 360 degrees of optical s
7. atus scannerSleep SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Stops both motors In normal awake operation the elevation motor runs at its current speed setting during gaps between commands while the azimuth motor stops The elevation motor may be stopped to conserve power and motor bearings during long idle periods This command does not affect the state of the processor or other electronics in the system Since the vertical axis motor startup time may be several seconds for higher speeds the scannerWake command should be used prior to the need for scan data 4 5 6 scannerWake int status scannerWake SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Starts the vertical axis motor and brings it to the last commanded speed Page 9 of 20 4 6 Scan and Turret Motion Commands Scan commands direct the SRI 500 to take one or more scans each consisting of a sequence of vertical line scans The elevation motor speed controls the rate of scan line acquisition The ratio of elevation and azimuth motor speeds previously specified controls the slope of the scan lines The start azimuth and elevation angle the number of vertical lines to be acquired the elevation resolution number of elevation motor encoder counts per range sample and the scan azimuth direction are specified in each command The timing of scan initiation depends on the mode previously set wi
8. can angle 4 4 1 azimuthSpeed int status azimuthSpeed SRI500 scanner int countsPerSec scanner Handle to the scanner instances as returned by OpenScanner counts PerSec Default 8000 counts sec Range 1 50 000 Sets the rotation speed of the turret during scans The turret speed will vary before and after scans as the turret is positioned for the next scan One revolution of the turret is 16000 counts The turret will stop after a scan if no further scans are queued 4 4 2 elevationSpeed int status elevationSpeed SRI500 scanner double linesPerSec scanner Handle to the scanner instance as returned by OpenScanner counts PerSec Default 500 0 Range 50 0 500 0 Sets the speed of the elevation motor This can up to one second to settle so the elevation motor may generally left running at constant speed The elevation motor does not stop after scans are completed The elevation speed in lines per second is converted to elevation motor encoder counts by multiplying by 16000 3 since there are 16000 encoder counts and 3 scans per revolution This can be used to calculate the range sampling rate from the elevation speed and elevation resolution in encoder counts per sample The latter is the elevationResolution parameter in singleScan and repeatingScan The scan speed parameters are not guaranteed to hold exactly during a scan although they will generally be close unless extreme platform motion occurs during a scan Act
9. cumstances that might result in injury or damage Ensure that the turret is free to move and that the system is firmly seated on a level surface Do not look into the window using magnifying optics Under control of the demonstration software the SRI 500 will take a scan from 360 to 360 degrees or 2 revolutions convert the received data and display the results The range image is shown above the reflectance image Light areas in the range image are nearby while darker areas are more distant In the reflectance image return signal strength is compensated for distance to obtain the actual reflectance of objects 4 9 SRI 500 data sheet following pages Page 16 of 20 SRI 500 Scanning Laser Rangefinder with Inertial Image Stabilization The SRI 500 Laser Rangefinder is an omnidirectional scanning range image acquisition system for obtaining range images from stationary or mobile platforms at distances up to 500 feet and 800 000 points per second Scanning is a combination of fast vertical scans at 500 lines s combined with an azimuth sweep rate of up to 1000 s 3D point datasets are acquired by setting vertical and horizontal Sweep rates and commanding acquisition of a sequence of vertical scan lines through a specified elevation and azimuth range The SRI 500 can be programmed to auto cycle through an azimuth region repeatedly automatically reversing direction The SRI 500 communicates with a host via a TCP IP connection The
10. d sent or the SRI 500 will cease executing commands other than the Halt command A Halt command will remove the pending scan from the queue 4 5 3 scannerTrigger int status scannerTrigger SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Initiates execution of a scan command if one is ready to run and the system is in the ScanOnSoftwareTrigger mode If either of these conditions is not true the command is disregarded Some latency will occur after transmission of the trigger command due to azimuth motor startup delay if the azimuth motor has slowed or reached a stop and to the delay for the vertical axis motor to reach the scan start position 4 5 4 scanOnHardwareTrigger int status scanOnHardwareTrigger SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Configures the SRI 500 to hold execution of each subsequent scan command until the trigger pulse input is high If the trigger is low when a scan command reaches the head of the command queue while in this mode the scanner stops the azimuth motor in a position appropriate for initiating the scan and awaits a high level on the trigger line Some latency will occur after transmission of the trigger signal due to azimuth motor startup delay if the azimuth motor has slowed or reached a stop and to the delay for the vertical axis motor to reach the scan start position Page 8 of 20 4 5 5 scannerSleep int st
11. host may issue Laser Enable Motor Speed and Take Scan commands through software based on sample source code provided with the scanner Each scan consists of a sequence of nearly vertical scan lines taken between start and stop platform azimuth and elevation angles Elevation coverage may be programmed from 65 to 65 and azimuth from 300 to 300 The scan head is capable of two complete rotations in azimuth lock to lock to maximize programming flexibility Optional Inertial Measurement Unit In mobile applications the optional internal inertial measurement unit captures platform vibration and rotation at 200 Hz and is used to correct the 3D coordinates of each sample point create a stabilized world referenced dataset Data for each scan is corrected to the initial platform inertial orientation during acquisition Platform orientation and velocity changes between and during scans are reported with each scan so multiple scans may be registered in a world map and vehicle motion may be derived In static applications the internal IMU may be used to register earth vertical which provides absolute orientation information for structures captured Acuit Technolog es Specifications Scan Angles Azimuth 360 Elevation 65 Scan Speed Vertical 500 lines s max Horizontal 1000 s max Measurement Acquisition Rate Approx 800 000 points sec peak during vertical scan Range Accuracy 10 1 5 inches Maximum Range
12. ified by the starting azimuth location and then accelerate to the current scan speed parameters and initiate a scan The repeatingScan command starts in the same way and reverses direction as rapidly as possible between scans Successive scans in a repeating scan are taken in opposite directions Time for the repeating scans will include the scan times and turret reversal times 4 6 2 haltScan int status haltScan SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Aborts the current scan and ceases data transmission Stops the azimuth motor This command is processed asynchronously so that any scan in progress is aborted before completion Scans queued prior to the Halt Scan command are flushed without execution Page 11 of 20 4 7 Scan Data Acquisition and Processing Data is received from the scanner once per vertical line of range points acquired The nLines parameter in createSRIPacketBuffer determines the number of vertical lines collected in each packet when receiveImagePacket is invoked The packet size is dependent on the number of lines in a packet and the number of range points per line The number of packets per scan depends on the number of lines in a packet and the number of lines in a scan Each packet has a scanld a packetNumber and a timestamp The scanld is the value provided when singleScan is invoked or the value provided when repeatingScan is invoked The timestamp is a measure of
13. ket in milliseconds newPacket target structure for packet data Acquires packets of data from the scanner Performs reception of packets and packet integrity checking Packets may be lost if this is not invoked before operating system buffers fill The sample code provided illustrates how this client size buffer size can be increased to reduce the risk of packet loss in the event of client data processing delays Transmission from the scanner to the client occurs once per vertical line acquired For minimum latency on the client create packets with only one line For lower overhead create packets with more lines Packet reassembly into a full image may be performed in the client with assembleImage Range and angle are converted into Cartesian coordinates in meters This should be invoked repeatedly with each packet received until the entire image has been assembled Page 13 of 20 4 7 4 createSRIImageBuffer SRIImage image createSRIImageBuffer int nLines int samplesPerLine nLines number of lines that will be in the image assembled in this image buffer samplesPerLine number of samples per scan line returns image Pointer to initialized structure and allocated space NULL if allocation was not successful Allocates image space and initializes structures for assembly of an image from packets received from the SRI500 Assembled Image Format SRIImage Struct SRIImage d int nLines int samplesPerLine long scanTimeSta
14. mage image returns eNoError or eInvalidAlloc if nota valid image pointer image Pointer returned by createSRIImageBuffer Frees image space allocated by createSRIImageBuffer 4 7 6 addPacketToImage int status addPacketToImage SRI500 scanner SRIPacket packet SRIImage imageBuffer scanner Handle to the scanner instances as returned by OpenScanner packet Pointer to the packet received imageBuffer SRIImage structure allocated by the calling software returns ePacketSizeMismatchif samplesPerLine ofthe packet does not match that of the image Page 15 of 20 4 8 Demonstration Client Software The demonstration program SRI500Client exe which runs under Windows XP is supplied in bin This program was compiled with Microsoft Visual C 6 0 It demonstrates the SRI500 API and programmable modes The client demonstration software include routines for converting range azimuth and elevation counts and signal strength to corrected range target reflectance and Cartesian coordinates with the scanner at the origin To check connectivity between the client and SRI 500 start the SRI 500 and wait seconds for the power up and turret centering process to complete Then start the client demonstration program SAFETY NOTE The turret will move rapidly and laser light is emitted from the window during demonstration program operation Although the SRI 500 laser output is safe in normal operation care should be taken to avoid cir
15. mp time of the first packet added to image float x float y float z float reflectance unsigned time The SRIImage structure matches the data that was specified in the original scan command The scan TimeStamp is the elapsed time from the start of the scan in microseconds This elapsed time can be converted to time relative to other scans by adding scanTimeStamp to the value The start of the scan is the time at which the scan command or trigger is detected and execution of the scan begins The first range measurement is taken after the azimuth motor has reached the commanded starting position and speed The structure contains five arrays The first three of these contain the x y z point locations in meters from the rangefinder at the time the pixel was acquired The fourth contains the surface reflectances Reflectance can vary slightly from unit to unit with temperature and with the cleanliness of the scanner window The time array is the elapsed time from the start of the scan in microseconds of each sample in the scan This elapsed time can be converted to time relative to other scans by adding scan TimesStamp to the value The start of the scan is the time at which the scan command or trigger is detected and execution of the scan begins The first range measurement is taken after the azimuth motor has reached the commanded starting position and speed Page 14 of 20 4 7 5 deleteSRIImageBuffer void deleteSRIImageBuffer SRII
16. nches Azimuth 0 02 resolution Elevation 0 01 resolution Relative Return Signal Strength Time From Previous Sample Packet Trailer Timestamp Inertial Velocity Change from Scan Start Inertial Azimuth Change From Scan Start Reference Coordinate Systems for Output Data With Inertial Option Elevation angle relative to Earth Vertical Azimuth relative to platform orientation at start of scan OR relative to instantaneous platform orientation Without Inertial Option Elevation and azimuth relative to instantaneous platform orientation Command Set Set Azimuth Scan Speed Set Elevation Scan Speed Take Single Scan Take Repeating Scans Auto reverse in azimuth Laser Enable Halt Scan Maximum Scan Duration 10 000 vertical lines 20 seconds up to 600 azimuth Minimum Scan 1 vertical line 2 milliseconds Acuity Technologies i H 4X Q 27 THRU EH 54 50 SRI 500 10 00 Acuity Technologies 3475 Edison Way Suite P Menlo Park CA 94025 56 i 19 70 i 7 13 Y y THIS DRAWING IS CONFIDENTIAL AND IS THE EXLCUSIVE PROPERTY OF ACUITY TECHNOLOGIES RIGHTS TO DISCLOSE USE MANUFACTURE OR REPORDUCE MUST BE OBTAINED IN WRITING FROM ACUITY TECHNOLOGIES
17. om an automotive or similar power system The supply must be capable of up to 50 amps burst 0 1 sec and 15 amps continuous 24 28V systems are also available Wire the power supply to the connector cables and plug in the connector with the power switch off then turn on the system An input trigger signal logic high is available on the input connector External triggering of a pre loaded scanning instruction sequence allows precise synchronization with external events If not used this input should be left unconnected On power up the turret will seek center and stop with the optical axis aligned with one edge of the scanner housing The turret window is not aligned with the optical axis so the window will be at a 10 angle to the housing Connect the SRI 500 ethernet jack to a hub router or access point with a CAT 5 Ethernet cable or to a client machine with a crossover cable Pin A Power JA Ke Pin B Ground AOLO OD Pin C Scan Trigger Input 1 p SE JJ Pin D Scan Trigger Return NC oe If the Scan Trigger Input is used this line must be connected to logic ground in the signaling device 3 Software Installation 3 1 CD Directory Structure The SRI 500 comes with a disk with the following contents doc API and users guide bin precompiled client for Windows XP sre client source code 3 1 1 Ethernet Connectivity The SRI 500 is configured with a static IP address of 192 168 0 231 It is recommended that this be lef
18. t unchanged to avoid difficulty in communicating with the SRI 500 If it is necessary to change the IP address or use DHCP contact Acuity for assistance Page 4 of 20 It is recommended that the scanner be used on a 100 Mb ethernet link with only the SRI 500 and the client machine since the SRI 500 can use nearly the entire bandwidth of this link Depending on the scan speeds selected other systems may also use the link although it is possible that image data will be lost occasionally Commands are sent to the scanner via TCP and image data is returned via UDP so delivery of the latter is not guaranteed in a network environment 3 2 Software Installation under XP The SRI 500 installation program starts automatically from the provided CD Contents are installed by default into Program Files SRI500 3 3 Software Installation under Linux The sample client program may be compiled and executed under most versions of Linux A makefile is provided in src 4 Programming Interface 4 1 Overview The Application Programming Interface to the SRI 500 consists of commands that set SRI 500 operation modes and parameters and perform scanning sequences When a command function is called parameters are validated and a command packet is sent to the scanner over Ethernet using TCP Up to 3 commands may be transmitted at once and will be buffered in the SRI 500 until executed Each call returns a status value which indicates whether the command was v
19. t side software included with the scanner 1 2 Use and Maintenance The SRI 500 is a rugged system designed for use on mobile platforms However it should be protected from severe shock and vibration such as that which might be experienced on a vehicle without suspension or with high engine vibration In these cases the scanner should be mounted with grommets The motors for the turret and scanning mirror are brushless DC motors which will not generally need maintenance over the life of the scanner The scanner is filled with dry nitrogen and sealed to prevent condensation and corrosion Do not open the scanner or break any seals Doing so will void the warranty and necessitate repair The front window is filter glass and should be kept clean ad free of scratches and dirt 1 3 Azimuth Motor Path Planning The turret of the SRI 500 moves through scans at nearly constant speeds To accomplish this the SRI 500 performs intelligent path planning which moves the azimuth motor into the correct position and speed for the next scan For this to operate efficiently it is recommended that the repeating scan command be used or that commands be queued so that the next scan may be anticipated by the path planning algorithm A turret positioning command is also available to preposition the turret for quick scan response Page 3 of 20 2 Hardware Power Up 2 1 Power Signal Connection The SRI 500 requires 11 to 18 Volts and is designed to draw fr
20. th the Mode command group 4 6 1 singleScan repeatingScan int status singleScan SRI500 scanner int azimuthStart int azimuthEnd int elevationStart unsigned pointsPerLine unsigned elevationResolution int status repeatingScan SRI500 scanner int azimuthStart int azimuthEnd int elevationStart unsigned pointsPerLine unsigned elevationResolution unsigned numberOfScans scanner Handle to the scanner instances returned by OpenScanner azimuthStart Range 15000 to 15000 or 330 to 330 degrees azimuthEnd Range 15000 to 15000 or 330 to 330 degrees elevationStart Range 1500 to 1500 or 67 5 to 67 5 degrees pointsPerLine Range 1 to 3001 or 67 5 to 67 5 degrees elevationResolution Range to 2000 counts per point numberOfScans Range gt 0 A value of 0 will repeat until haltScan or power down The number of vertical lines obtained in the scan is determined by the speeds most recently specified with elevationSpeed and azimuthSpeed The ending elevation angle of each scan line is determined by pointsPerLine and elevationResolution Any points below 67 5 degrees elevation will not be sampled Note that the optical angle change between successive points will be twice the motor encoder angle change in elevation due to mirror geometry specifying a sample every elevation encoder count results in angular separation of the samples of 360 8000 045 degrees Example Scan through 135 degrees in
21. the time the first sample of the packet was taken After the scanld is a packet number ID This starts at 1 with each new scan Following this is the total number of packets that this image will arrive in and first next line of data in the scan Direct operations on the packets by client code will generally only need to be performed by the functions described below 4 7 1 createSRIpacketBuffer SRIImage packet createSRIpacketBuffer int nLines int samplesPerLine returns packet Pointer to initialized structure and allocated space NULL if allocation was not successful Struct SRIPacket short scanld short packetNumber long packetTimeStamp short checksum unsigned char data k_dataPacketSize D Allocates image space and initializes structures for assembly of an image from packets received from the SRI500 In typical usage a client application might create one of these execute receivelmagePacket followed by addPacketToImage and then re use the packet buffer to obtain the next packet 4 7 2 deleteSRIpacketBuffer int status deleteSRIpacketBuffer SRIpacket packet returns eNoError or eInvalidAlloc ifnota valid packet pointer Frees packet space allocated by createSRIpacketBuffer Page 12 of 20 4 7 3 receivelmagePacket int status receivelmagePacket SRI500 scanner unsigned timeout SRIPacket packet scanner Handle to the scanner instance as returned by OpenScanner timeout time to wait for a pac
22. ual locations speeds and times of each range sample in a scan are reflected in the coordinates and timestamp of each range point 4 4 3 azimuthPosition int status azimuthPosition SRI500 scanner int counts scanner Handle to the scanner instances as returned by OpenScanner counts Range 15000 15 000 Sets the position of the azimuth motor The turret will move to the commanded location If no further commands are queued after this one the turret will stop at that position This may be used to position the turret ahead of time so that the delay between triggering a scan and actual rangefinding is minimal Page 7 of 20 4 5 Mode Commands 4 5 1 scanOnCommand int status scanOnCommand SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Default setting Configures the SRI 500 to execute scan commands when they are received or when the previous command is completed and another is found in the queue 4 5 2 scanOnSoftwareTrigger int status scanOnSoftwareTrigger SRI500 scanner scanner Handle to the scanner instances as returned by OpenScanner Configures the SRI 500 to hold execution of each subsequent scan command until a Trigger command reaches the head of the command queue When a scan command reaches the head of the command queue while in this mode the scanner stops the azimuth motor in a position appropriate for initiating the scan Trigger command must be the next comman
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