Using the DAQ Adaptor for MATLAB
Contents
1. Table of Contents aaay bm nee 3 Data Flow Model 4 W kk kk kk kk KK KK KK KK KK KK kk kK kk kk kk kk 6 Requirements isi seio se sasie aasa siaii aa eg aas aa i aG ES 6 Installations o eeen ie nuk ae lan Adel Ki EE E en E aA 7 Using the DAQ Adaptor for MATLAB 004 8 Analog Input and Output 0 0 KK 10 Setting the Input Type Ah kk KK KK KK KK KK 11 Setting the Synchronization Mode TI Setting the Filter Type 2200 an ener eders 12 About Channel Level Properties 13 Configuring the Gain of aChannel 14 Configuring a Channel for an IEPE Input 15 Configuring a Channel for a Thermocouple Input 16 Configuring a Channel for an RTD Input 16 MATLAB Property Notes WWW 17 Multiple Subsystems of a Single Type 6 17 Analog Out Operation Notes 660 KK KK K 18 Using Hardware Triggers KK KK KK KK KK KK KK 19 Related Information 0 0 000000 ccc cece eee KK KK 19 Contents Data Translation DAQ Adaptor for MATLAB Overview This document describes how to install and use the Data Translation DAQ Adaptor for MATLAB Data Translation s DAQ Adaptor for MATLAB provides an interface between the MATLAB Data Acquisition DAQ subsystem from The MathWorks and Data Translation s DT Open Layers architecture DT Open Layers provides an API to all of Data Translation s analog and digital2. I O data acquisition hardware modules You can use these two components together to control Data Translation modules with MATLAB and move data directly into MATLAB for analysis and display Note Counter timer operations are not supported in MATLAB unless they are implemented as part of the analog I O data stream Using these components together you can create DT Open Layers subsystems add channels to them and perform single value or streaming I O through them to MATLAB MATLAB provides extensive analysis and display features to process the input data and generate output data Data Translation DAQ Adaptor for MATLAB Data Flow Model The figure below summarizes the relationship between the MATLAB and Data Translation components in a combined configuration Requirements You must install the following before you install the Data Translation DAQ Adaptor for MATLAB Your Data Translation hardware module s and their drivers from the Data Acquisition OMNI CD that ships with your hardware DT Open Layers Version 3 0 or higher MATLAB Version 7 R14 Service Pack 3 or higher MATLAB Data Acquisition Toolbox Version 2 7 or higher Install Data Translation components from a recent OMNI CD or download from our web site www datatranslation com Contact The MathWorks for updates to your MATLAB components Data Translation DAQ Adaptor for MATLAB Installation To install the DAQ Adaptor for MATLAB do the follo
3. data stream SyncMode Specifies the synchronization mode None Master or Yes No Slave for the analog input subsystem of the device DataFilterType Specifies the filter type Raw or MovingAverage for the Yes No analog input subsystem of the device a This property is visible only when a TEMPpoint or VOLTpoint instrument is specified 10 Data Translation DAQ Adaptor for MATLAB Setting the Input Type To specify whether a subsystem uses differential or single ended input channels use the MATLAB property inputtype For example this command configures the analog input subsystem ai0 to use differential input channels gt gt aid inputtype Differential To configure the analog input subsystem ai0 to use single ended channels use this command gt gt aid inputtype SingleEnded You can use the get aid command to see the changes When you change input types the channel list also changes Setting the Synchronization Mode Some devices provide a synchronization connector such as an LVDS RJ45 connector that allows you to synchronize operations on multiple devices In this configuration the subsystem on one device is configured as the master and the subsystem on the other device is configured as a slave When the master module is triggered both the master device and the slave device start operating at the same time If the device allows you to program the synchronization mod
4. Channel for an IEPE Input Use the DTOL specific properties ExcitationCurrentSource and Coupling to the configure a channel for an IEPE input For example the following commands configure the first channel channel 0 which is associated with the analog input subsystem ai0 for an IEPE input that uses an internal excitation current source and AC coupling gt gt aid channel 1 ExcitationCurrentSource Internal gt gt aid channel 1 Coupling AC To configure the same channel for an IEPE input that uses an external excitation current source and DC coupling use these commands gt gt aid channel 1 ExcitationCurrentSource External gt gt ai0d channel 1 Coupling DC To disable the excitation current source for the same channel use this command gt gt aid channel 1 ExcitationCurrentSource Disabled 15 Data Translation DAQ Adaptor for MATLAB 16 Configuring a Channel for a Thermocouple Input Use the DTOL specific property ThermocoupleType to the configure a channel for a thermocouple input For example the following command configures the first channel channel 0 that is associated with the analog input subsystem ai0 for a J type thermocouple input gt gt aid channel 1 ThermocoupleType J The UnitRange property for that channel will then reflect the temperature range in degrees C of the J type thermocouple input
5. DATA TRANSLATION UM 22024 G DAQ Adaptor for MATLAB Seventh Edition January 2009 Data Translation Inc 100 Locke Drive Marlboro MA 01752 1192 508 481 3700 www datatranslation com Fax 508 481 8620 E mail info datx com Copyright 2005 2009 by Data Translation Inc All rights reserved Information furnished by Data Translation Inc is believed to be accurate and reliable however no responsibility is assumed by Data Translation Inc for its use nor for any infringements of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent rights of Data Translation Inc Use duplication or disclosure by the United States Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer software clause at 48 C F R 252 227 7013 or in subparagraph c 2 of the Commercial computer Software Registered Rights clause at 48 C F R 52 227 19 as applicable Data Translation Inc 100 Locke Drive Marlboro MA 01752 Data Translation is a registered trademark of Data Translation Inc DT Open Layers DataAcq SDK Data Acquisition OMNI CD LV Link and DTx EZ are trademarks of Data Translation Inc MATLAB is a registered trademark of The MathWorks Inc All other brand and product names are trademarks or registered trademarks of their respective companies
6. Data read using Getdata and Getsample is returned in floating point format Configuring a Channel for an RTD Input Use the DTOL specific property RtdType to the configure a channel for an RTD input For example the following command configures the first channel channel 0 that is associated with the analog input subsystem ai0 for a Platinum 100 QRTD input with an alpha coefficient of 0 003850 gt gt aid channel 1 RtdType PT100 385 The UnitRange property for that channel will then reflect the temperature range in degrees C of the RTD input Data read using Getdata and Getsample is returned in floating point format Data Translation DAQ Adaptor for MATLAB MATLAB Property Notes The following adaptor specific notes apply to MATLAB properties Table 3 Adaptor Notes for MATLAB Properties MATLAB Property BufferingConfig Notes The minimum buffer size is 128 but for best performance set to 1024 or greater NOTE If the value for RepeatOutput is greater than 1 the buffer size must be an integer multiple of the number of samples queued The adaptor warns you of this when you change RepeatOutput TotalChannels This may include channels that are in two lists and have a mode single ended vs differential Also when the InputType is changed from SingleEnded to Differential the channel IDs will change in the DaqHwinfo listing TriggerCondition Either RisingEdge or FallingEdge depend
7. e SupportSynchronization is True use the DTOL specific property SyncMode to set the synchronization mode to one of the following values e None The subsystem is configured to ignore the synchronization circuit on the device e Master Sets the subsystem as a master the synchronization connector on the device is configured to output a synchronization signal 11 Data Translation DAQ Adaptor for MATLAB e Slave Sets the subsystem as a slave the synchronization connector on the device is configured to accept a synchronization signal as an input The following command sets the synchronization mode of the analog input subsystem to Master gt gt aid SyncMode Master Setting the Filter Type Some devices such as TEMPpoint and VOLTpoint instruments support a software programmable filter type for the analog input subsystem For these devices the following filter types are available e Raw No filter Provides fast response times but the data may be difficult to interpret Use when you want to filter the data yourself The Raw filter type returns the data exactly as it comes out of the Delta Sigma A D converters Note that Delta Sigma converters provide substantial digital filtering above the Nyquist frequency Generally the only time it is desirable to turn off the software filter is if you are using fast responding inputs sampling them at higher speeds gt 1 Hz and need as much response speed as po
8. ing Hardware Triggers To use a hardware trigger for analog output operations set the TriggerType to HwDigital and set the TriggerCondition property to Rising or Falling When the analog output subsystem is started data buffers may be sent to the hardware FIFO resulting in a buffer done message to the adaptor and a trigger event before the D A output value has been set Therefore it may appear that data output occurs before the hardware trigger happens but the data has only been moved to the board FIFO not output through the D A converter Related Information Refer to the following documents from Data Translation for more information on using DT Open Layers DataAcg SDK User s Manual UM 18326 For programmers who are developing their own application programs using the Microsoft C compiler this manual describes how to use the DT Open Layers DataAcg SDK to access the capabilities of Data Translation data acquisition devices DTx EZ Getting Started Manual UM 15428 This manual describes how to use the ActiveX controls provided in DTx EZ to access the capabilities of Data Translation data acquisition devices in Microsoft Visual Basic or Visual C 19 Data Translation DAQ Adaptor for MATLAB 20
9. ing upon what the module supports Multiple Subsystems of a Single Type To provide access to all elements of a device with multiple subsystems of a particular type for example multiple analog input subsystems such as on the DT9822 the adaptor creates virtual boards The first board enumerated includes any other types of subsystems 17 Data Translation DAQ Adaptor for MATLAB For example the DT9822 module enumerates in the adaptor like this DT9822 01 A D D A Digital 1 O DT9822 01 1 A D DT9822 01 2 A D DT9822 01 3 A D To access the fourth A D subsystem use the virtual board DT9822 01 3 and its one analoginput object Analog Out Operation Notes The following caveats apply to analog output operations The number of samples output will not always be correct particularly when the samples to output are not the same as the buffer size This is because DT Open Layers sends the whole buffer to the D A converter and the adaptor pads the output buffer to either the Hold value or the channel default value see OutOfDataMode e DT Open Layers does not send a message when the actual hardware trigger occurs Therefore the time and sample count for the trigger event will not be correct for TriggerType HwDigital for analog out The final voltage on a D A output might be unpredictable after a streaming operation 18 Data Translation DAQ Adaptor for MATLAB Us
10. nel The following thermocouple types are supported J K B E N R S T or None If you specify None for the ThermocoupleType data is read as voltage from the corresponding channel and the UnitRange reflects the voltage range supported by the device If you specify a value other than None for the ThermocoupleType data is read as temperature from the corresponding channel and the UnitRange reflects the temperature range in degrees C of the specified thermocouple type Data read using Getdata and Getsample is returned in floating point format Specify the RTD type for a particular analog input channel The following RTD types are supported Volts Ohms PT100 385 PT500 385 PT1000_385 PT100 392 PT500 392 PT1000 392 A D Yes Yes D A No No Configuring the Gain of a Channel Use the DTOL specific GainPerChan property to set the gain for a channel For example this command sets the gain for the first channel channel 0 of the analog input subsystem ai0 to 4 gt gt aid channel 1 GainPerChan 4 Data Translation DAQ Adaptor for MATLAB Note DT Open Layers uses a per channel gain concept which differs from MATLAB s range based per channel setting to control gain and range You can specify a per channel gain or the adaptor attempts to set the best per channel gain for a specified range We recommend using the GainPerChan property for per channel gain control Configuring a
11. ollowing subsections For more information about using MATLAB commands and MATLAB Data Acquisition Toolbox properties refer to your MATLAB documentation Data Translation DAQ Adaptor for MATLAB Analog Input and Output The Data Translation DAQ Adaptor for MATLAB provides the following adapter specific properties for analog I O operations Table 1 Adaptor Specific Analog Input Output Properties Property Description A D D A FIFOAvailable Determines if a FIFO is available on the subsystem No Yes FIFODepth Determines the size of the FIFO No Yes OutOfDataMode Specifies how to handle an out of data condition Set No Yes Hold to use the last value in the output buffer Set Default to use the channel specific Default Value property SupportBinaryEncoding Determines if the subsystem uses binary encoding Yes Yes SupportExternalTriggerFalling Checks for external falling edge triggering support Yes Yes SupportExternalTriggerRising Checks for external rising edge triggering support Yes Yes SupportGainPerChannel Determines if the subsystem supports different gain Yes Yes values for each analog channel SupportSoftTrigger Determines if the subsystem supports an internal Yes Yes software trigger SupportTwosComp Determines if the subsystem uses twos complement Yes Yes encoding ReturnCjcTemperatureln Specifies whether to return CJC values in the analog Yes No Stream input
12. se the MATLAB command getsample as follows gt gt s getsample ai0 You can display the properties of an adaptor including installed hardware modules with the daghwinfo command This example shows how to display the properties of the DTOL adaptor using the daqhwinfo command gt gt daqhwinfo dtol If there are too many devices to display on a single line you can assign daqhwinfo to an array and query the name of each device separately as shown in this example gt gt x daghwinfo dtol gt gt x BoardNames Data Translation DAQ Adaptor for MATLAB You can examine properties of a subsystem that you created with the adaptor by using the MATLAB daghwinfo command for built in properties and the get command for user settable properties In this example the first command shows all the built in properties of the analog input subsystem ai0 and the second command shows all the DTOL user settable properties of the analog input subsystem ai0 gt gt daqhwinfo ai0 gt gt get ai0 You can find out more information about a property using the MATLAB propinfo command For example this command shows how to get information about the GainPerChan property that is associated with channel 1 of the analog input subsystem ai0 gt gt propinfo ai0 channel 1 GainPerChan To control a data acquisition session issue MATLAB commands and set the appropriate DTOL properties described in the f
13. ssible MovingAverage Provides a compromise of filter functionality and response time This filter can be used in any application This low pass filter takes the previous 16 samples adds them together and divides by 16 The following command sets the filter type of the analog input subsystem to MovingAverage gt gt ai0 DataFilterType MovingAverage 12 Data Translation DAQ Adaptor for MATLAB About Channel Level Properties The following properties appears at the channel level after you add a channel Table 2 Adaptor Specific Channel Property Property Coupling Description For devices that support IEPE inputs specify the coupling type AC or DC for a particular analog input channel A D Yes D A No ExcitationCurrentSource GainPerChan For devices that support IEPE inputs specify the excitation current source for a particular analog input channel Possible values are Internal excitation current source is on the device External excitation current source is external to the device or Disabled no excitation is applied Specify the gain value for a particular analog input channel Yes Yes No No 13 Data Translation DAQ Adaptor for MATLAB 14 Table 2 Adaptor Specific Channel Property cont RtdType Property ThermocoupleType Description Specify the thermocouple type for a particular analog input chan
14. wing 1 2 Click the link for the adaptor on Data Translation s web site Choose Open from the Windows dialog box or choose Save to download the file before proceeding If you chose the save the file double click setup exe after you download it Close other programs if necessary and click Next on the welcome screen Either change the directory path using Browse or accept the default directory and then click Next The installer asks you whether to back up replaced files Choose the Yes or No radio button and then click Next The installer prompts you to begin file installation Click Next The installer copies the files to the destination directory After the installer copies the files it launches MATLAB MATLAB registers the DAQ Adaptor DLL using the path you provided gt gt rehash toolboxcache daqregister C PROGRA 1 DATATR 1 DAQADA 1 dtol d11 quit gt gt When you return to the installer click Finish Data Translation DAQ Adaptor for MATLAB Using the DAQ Adaptor for MATLAB The Data Translation DAQ Adaptor for MATLAB is specified as dtol in MATLAB code The following example shows how to create an analog input object ai0 using the DTOL adaptor for a device at index 0 gt gt ai0 analoginput dtol 0 To add hardware channel 1 to the ai0 object use the MATLAB command addchannel as follows gt gt addchannel ai0 1 To get a single sample from that channel u
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