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DTx-EZ

1. 0 6 c eee eee eee 193 MOV ia cae aint en d areca E a Meh haa ee ie aa ake 195 About this Manual This manual describes how to get started using DTx EZ to develop application programs for data acquisition boards that conform to the DT Open Layers standard Intended Audience This document is intended for engineers scientists technicians or others responsible for developing application programs using the Microsoft Visual Basic or Visual C compiler to perform data acquisition operations It is assumed that you are a proficient programmer that you are experienced programming in the Windows 98 Windows NT Windows Me Millennium Edition or Windows 2000 operating environment on the IBM PC or compatible computer platform that you have familiarity with data acquisition principles and that you have clearly defined your requirements What You Should Learn from this Manual This manual provides installation instructions summarizes the functions provided by the DTx EZ and describes how to use the properties methods functions and subroutines to develop a data acquisition program Using this manual you should be able to successfully install the DTx EZ software and get started writing an application program for data acquisition This manual is intended to be used with the online help for the DTx EZ which you can find in the same program group as the DTx EZ software The online help for the DTx EZ contains
2. o Software Architecture Introductio ai a ea Saeed oy aies g2 System Operations e ss sss cs cii d epas traiak ka yE EEES 93 Analog and Digital I O Operations 0 99 Counter Timer Operations n usares nnns nrnna 137 Simultaneous Operations suseni surr r arenen 164 Plot Control Operations 000 00 166 91 Chapter 5 Introduction This chapter provides conceptual information to describe the following operations provided by DTx EZ e System operations described starting on page 93 e Analog and digital I O operations described starting on page 99 e Counter timer operations described starting on page 137 e Simultaneous operations described starting on page 164 and e Plot control operations described starting on page 166 Use this information with the reference information provided in DTx EZ online help when programming your data acquisition boards refer to page 13 for more information on launching this help file 92 Software Architecture System Operations DTx EZ provides functions to perform the following general system operations e Initializing and specifying a board this page e Specifying a subsystem this page e Configuring a subsystem page 95 e Handling events page 96 e Handling errors page 96 and e Halting the operation page 98 The following subsections describe these operations in more detail Initializing and Specify
3. MaxRangeValues Property Lists a subsystem s maximum voltage range values 49 Chapter 3 Table 4 Information Properties and Methods cont Query About Properties and Methods Description Subsystems MinRangeValues Property Lists asubsystem s minimum voltage cont range values hDass Property Returns the handle of the current subsystem Software LastError Property Retrieves the last known DT Open Layers error generated by the DTAcq32 Control LastErrorDescription Property Retrieves a string representation of the last known DT Open Layers error generated by the DTAcq32 Control Table 5 lists the subsystem capabilities that you can query using the GetSSCaps method Note that capabilities may be added as new boards are developed for the most recent set of capabilities refer to the DTx EZ online help Table 5 Capabilities to Query with the GetSSCaps Method Query About Capability Method Returns Data Flow OLSSC_SUP_SINGLEVALUE Non zero if subsystem supports Mode single value operations OLSSC_SUP_CONTINUOUS Non zero if subsystem supports continuous post trigger operations OLSSC_SUP_CONTINUOUS_ PRETRIG Non zero if subsystem supports continuous pre trigger operations OLSSC_SUP_CONTINUOUS_ ABOUTTRIG Non zero if subsystem supports continuous about trigger both pre and post trigger operations 50 Proper
4. GetDevCaps Method Returns the number of elements for a specified subsystem type ona specified device 48 Property Method Function and Subroutine Summary Table 4 Information Properties and Methods cont Query About Properties and Methods Description Subsystems GetSSCaps Method Returns whether a specified cont subsystem capability is supported and or the number of capabilities supported Refer to Table 5 for a list of possible capabilities and return values GetSSCapsEx Method Gets information about extended subsystem capabilities including the minimum and maximum throughput retrigger frequency clock divider value and base clock frequency EnumSSCaps Method Lists the possible settings for specified subsystem capabilities including filters ranges gains and resolution numFilters Property Returns the number of available filter settings for a subsystem FilterValues Property Lists filters available to the selected subsystem numGains Property Returns the number of available gain settings for a subsystem GainValues Property Lists the subsystem s available gain values numResolutions Property Returns the number of available resolution settings for a subsystem ResolutionValues Property Lists a subsystem s available resolution values numRanges Property Returns the number of available range settings for a subsystem
5. hardware specific clocks extra N to select an extra available internal clock Using an internal clock No Specify the y frequency of the Frequency Property C T output The C T subsystem produces the actual frequency as closely as possible to the number specified Specify external 1 to select the external clock or one of the hardware specific clocks ClockSource Property extra N to select an extra available external clock Specify a clock divider to apply to the v external clock source The driver sets the ClockDivider Property actual clock divider as closely as possible to the number specified MA y Specify the gate to enable or trigger a GateType Property counter timer operation 183 Appendix A 184 Stop the Operation Pause the Pause Method operation 2 No Stopinan orderly Stop Method way Continue Method The Stop method stops the operation on the subsystem in the recommended way the current inprocess buffers are filled or emptied and put on the done queue The driver posts at least one BufferDone and QueueStopped event Reinitialize Reset Method Abort Method The Abort and Reset methods stop the operation on the subsystem immediately the current buffers are not filled or emptied before they are pu
6. 2 Check your distribution disk for a README file If present this disk will include the latest installation and configuration information 3 Check that you have installed the device driver for your board properly 4 Check that you have installed your hardware properly Note If you are still having problems follow the instructions provided in the next section 192 Product Support Service and Support For the latest tips software fixes and other product information you can always access our World Wide Web site at the following address http www keithley com If you have difficulty using DTx EZ the Keithley Technical Support Department is available to provide technical assistance For the most efficient service complete the form on page 194 and be at your computer when you call for technical support This information helps to identify specific system and configuration related problems and to replicate the problem in house if necessary 193 Chapter 6 194 Name Information Required for Technical Support Phone Contract Number Address Hardware product s serial number configuration Device driver version Software serial number version PC make model operating system Windows version processor version speed RAM hard disk space network number of users disk cache graphi
7. see page 184 Figure 19 Performing a Continuous Buffered Output Operation cont 82 Programming Flowcharts Event Counting Operations The flowchart in Figure 20 provides an overview of the steps required to perform an event counting operation Many steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes sot the board with the Board oper Select a C T subsystem with the SubSystem property or use the SubSysType and SubSysElement properties Vv Set the cascade mode using the CascadeMode property y Set up the clocks and gates see page 183 A Specify the count events counter timer mode by setting the CTMode property to event counting 0 e _ Configure the subsystem using the Config method N Go to the next page C i A Figure 20 Performing an Event Counting Operation 83 Chapter 4 AN Continued from previous page D v Start the operation using the Start method ie AA Read the events counted using the CTReadEvents method Yy Ye Get update ids of events total Stop the operation see page 184 Figure 20 Performing an Event Counting Operation cont 84 Programming Flowcharts Frequency Measurement Op
8. the xAutoScale property to True 187 Appendix A Set the Plot s y Axis Autoscale i Set the axis lower limit y axis yMin Property C yMax Property Set the axis upper limit Enable the autoscale feature for the y axis by setting AutoScale Propert Q p y the yAutoScale property to True 188 Flowcharts for Substeps Set Grid Parameters GridStyle Property i Set the line style for the grid Display x axis on GridXOn Property grid Yy GridXStart Property y GridXSpacing Property Display y axis on GridYOn Property grid Yy GridYStart Property y GridYSpacing Property Make line Yes spacing relative Enable the x axis grid lines Set the first line on the x axis Specify the amount of space to place between the lines on the x axis Enable the y axis grid lines Set the first line on the y axis Specify the amount of space to place between the lines on the y axis Set the GridAutoScale property equal to TRUE Doing so means the grid lines never seem to change GridAutoScale Property position to reflect buffers of varying size or zooming on the part of the user Instead the scaling between the lines changes allowing the grid lines to remain in a fixed position 189 Appendix A Set Mark
9. 156 OLSSCE_MAXTHROUGHPUT 123 155 OLSSCE_MINCLOCKDIVIDER 124 156 OLSSCE_MINTHROUGHPUT 123 155 one shot operation 148 repetitive support 55 151 support for 55 148 online help 12 13 operation stopping 98 OverrunError event in buffer input operations 178 in buffer output operations 181 P Palette property 70 167 in setting plot appearance 185 parameters set for channel 173 set for grid 189 set for markers 190 set for subsystem 172 pause an operation 184 support for 51 Pause method 61 184 in continuous operations 114 in event counting operations 139 in rate generation operations 145 in repetitive one shot operations 152 plot automatic scaling 167 enable disable repaint 167 enable disable update on each element change 167 set appearance 185 set line style 167 Index set line s color 167 set line s width 167 set pre operation parameters 186 set scale for 167 set starting point 167 plotting control operations performing 89 plotting data 166 positive analog threshold trigger support 54 126 PowerOff method 62 PowerOn method 62 pre starting subsystems 164 PreTrigBufferDone event 131 in buffer input operations 178 pre trigger continuous operations 115 specifying 174 support for continuous operation 50 115 PreTrigger function in continuous about trigger operations 117 PreTrigger property 60 125 in continuous pre trigger operations 116 in setting pre trigger parameters 174 PreTriggerBufferDone eve
10. Single Ended External Differential Encoding Offset Binary ClockS ource _ 2 s Complement Internal Trigger Source Internal Figure 5 Configure the Analog Output Settings 3 Select Configure gt Acquisition to configure your output waveform The Acquisition Options dialog box shown in Figure 6 appears 26 Using the DTx EZ Examples amp Acquisition Options x Output Options O Use DMA Generate Waveform O Square Sine O Triangle Peak Voltage Wave Frequency Sample Frequency Figure 6 Configure Output Waveform Click Use DMA to enable direct memory access DMA for data transfer operations For optimum speed DMA should be enabled on boards that support it Select the type of waveform you wish to produce and then select the waveform s peak voltage the wave frequency and the board s sample frequency When you ve completed the setup click OK Select Start to begin outputting a continuous waveform Note that the name changes to Stop until the operation completes You can choose Stop to halt the operation at any time Select ViewOutput to display the waveform on your screen Figure 7 shows a typical sine wave 27 Chapter 2 28 Eid DTx EZ Dac Waveform generation DIDEMO iol x 10 Volts Ov 0 Seconds 2 6 DAC Buffers Done 2 Drag cursor with Right Mouse button to Zoom In Double Click Left
11. subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own Yes BufferReused l You may want to tools In such cases the Visual C increment a counter appears in italics following the Visual Basic name Get Yes e Report that the The queue related events are queue relat operation has stopped QueueDone and QueueStopped ed event No v fa C Go to the next page p 181 Appendix A 182 Deal with Events and Buffers for Output Operations cont Continued from previous page Get BufferDone event Yes Refill buffers No Yes Using Visual Basic CopyToBuffer Subroutine No y olDmGetBufferPtr Copy all the samples from a Visual Basic array to a buffer Get a pointer to the buffer Wait for Return to the top of message page 181 gt y Fill the buffer Indicate the v number of SetValidSamples Valid samples Subroutine in the buffer olDaGetValidSamples Recycle the Queue Property buffer if you want the subsystem to fill it again when using no buffer or multiple buffer wrap Flowcharts for Substeps Set Clocks and Gates for Counter Timer Operations Yes Specify internal 0 the default to select ClockSource Property the internal clock or one of the
12. timer C T subsystem To specify the counter to use in software specify the appropriate C T subsystem For example counter 0 corresponds to C T subsystem element 0 counter 3 corresponds to C T subsystem element 3 DTx EZ defines the following capabilities that you can query and or configure for counter timer operations e Counter timer operation mode page 138 e Clock source page 154 e Gate type page 157 and e Pulse output type output duty cycle and width page 162 The following subsections describe these capabilities in more detail 137 Chapter 5 Counter Timer Operation Mode DTx EZ supports the following counter timer operations e Event counting this page e Frequency measurement page 140 e Rate generation continuous pulse output page 144 e One shot page 148 and e Repetitive one shot page 151 The following subsections describe these counter timer operations Event Counting Use event counting mode to count events from the counter s associated clock input source To determine if the subsystem supports event counting use the GetSSCaps method specifying the capability OLSSC_SUP_CTMODE_COUNT If this method returns a non zero value the capability is supported To specify an event counting operation use the CTMode property specifying the count events 0 parameter Specify the C T clock source for the operation In event counting mode an external C T clock source is more us
13. 0 cee cee eee eee eens xv Where to Get Help 0 6 cece eee xvi Chapter 1 Overview 20 00 e eee eee eee 1 Whaat is DIX EZ cca cae eucds oe th eed Raa Ea eke Eea ea 2 Conforms to the DT Open Layers Standard 2 Provides Custom Controls 00 eaaa 2 The Data Acquisition Custom Control 3 The DT Plot Custom Control 02 0005 3 Provides Properties Methods and Events 4 Provides Function and Subroutine Libraries 5 Follows Object Oriented Design 00000 eee 6 Provides Extensive Example Programs 6 Provides Multiple Board Support 006 6 Provides High Performance 000 000005 7 What You Need 00 0 c cece cece teen eee eee 8 Installationen ine e a ee ea o eA wae 9 Adding DTx EZ Custom Controls to Your Project 10 Adding to a Visual Basic 6 0 Project 00 10 Adding to a Visual C 6 0 Project 0000008 11 Creating an Application 0 0000 e eee eee 12 Using the DTx EZ Online Help 0 0004 13 vii Contents viii Chapter 2 Using the DTx EZ Examples 15 About the Examples 60 6 E EAE eee eee 16 Running the Examples as Applications 17 Opening the Examples from within Visual Basic 18 Opening the Examples from within Visual C 19 A D Burst Examples
14. Counting Operations 0666 e cece eee eee 83 Frequency Measurement Operations 000 85 Pulse Output Operations 0 000 87 Plotting Control Operations 666 sassari rnrn 89 75 Chapter 4 Introduction If you are unfamiliar with the capabilities of your board and or subsystem query the device as follows To determine the number and types of DT Open Layers boards and drivers installed use the numBoards and the BoardList properties To determine the subsystems supported by the board use the EnumSS or GetDevCaps method To determine the capabilities of a subsystem use the GetSSCaps or GetSSCapsEx method specifying one of the capabilities listed in Table 5 on page 50 To determine the gains filters resolutions and ranges if more than one is available use the EnumSSCaps method or these sets of properties Gains numGains and GainValues Filters numFilters and FilterValues Resolutions numResolutions and ResolutionsValues Ranges numRanges MinRange Values and MaxRange Values Then follow the flowcharts presented in the remainder of this chapter to perform the desired operation Note Although the flowcharts do not show error checking it is recommended that you check for errors after using each property method function and subroutine 76 Programming Flowcharts Single Value Operations The flowchart in Figure 17 provides
15. D subsystem on the DataAcq EZ boards has 16 available channels To access multiple channels you must set up a list of channels you want to sample The DataAcq EZ boards also provide programmable gains To program the gains on the channels you need to set up a gain list to accompany the channel list The DT Plot Custom Control The DT Plot Custom Control is a high speed plotting control useful for plotting fixed or floating point data in your Visual Basic or Visual C application Since the DT Plot Custom Control works directly with DT Open Layers hBuf data the need to copy the buffer to an array is eliminated Chapter 1 You fill a buffer with data you want to plot and assign it to the plot s Buffer property You can plot from 1 to 16 channels of data at a time all with different colors You may also choose from a variety of line styles and the following features e xandy grid lines that you can set to automatically scale to your data or to remain at fixed spacing intervals e xand y markers that can be used to indicate a zoom in section of the data or to determine the data value at that position e Astripchart mode so you can plot many buffers of rapidly changing continuous data and see all of them on the plot s display e A single point feature when in strip charting mode that allows you to add one point of data at a time to the display At design time the DT Plot Custom Control displays a randomly generated data p
16. Mouse button to Zoom Out Figure 7 Displaying a Waveform You can zoom in on a portion of the data by right clicking on the plot and then dragging the red dotted selection bars Double click the left mouse button to zoom out again Using the DTx EZ Examples Continuous A D Example This example contdisp vbp or contdisp mdp continuously samples a single analog input channel to memory and plots the data on screen using pre defined buffer and frequency settings You could use this example to detect data trends by immediately viewing the effect of changing stimulus Click Start to begin the acquisition click Stop to end it Figure 8 shows a typical acquisition 20 Eid Continuous ADC Data Display Jol x Figure 8 Continuous A D Display 29 Chapter 2 30 The Y axis setting volts corresponds to the minimum and maximum voltage settings for the selected board The X axis setting seconds is determined by the data buffer size and selected sampling frequency You can modify these properties within the example s form_load event subroutine Using the DTx EZ Examples Single Value Example This example sv vbp or sv mdp acquires a single sample from a single analog input channel and outputs a single value on the DAC you specify You can use this example to check for correct configuration to monitor slowly changing inputs or to provide a constant or slowly varying voltage output When you run it the
17. OLSSC_SUP_GATE_LOW LEVEL_DEBOUNCE Non zero if subsystem supports low level gate type with input debounce OLSSC_SUP_GATE_HIGH EDGE_DEBOUNCE Non zero if subsystem supports high edge gate type with input debounce OLSSC_SUP_GATE_LOW EDGE_DEBOUNCE Non zero if subsystem supports low edge gate type with input debounce OLSSC_SUP_GATE_LEVEL DEBOUNCE Non zero if subsystem supports level change gate type with input debounce Interrupt OLSSC_SUP_INTERRUPT Non zero if subsystem supports interrupt driven I O Property Method Function and Subroutine Summary Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns FIFOs OLSSC_SUP_FIFO Non zero if subsystem has a FIFO in the data path Processors OLSSC_SUP_PROCESSOR Non zero if subsystem has a processor on board Software OLSSC_SUP_SWCAL Non zero if subsystem supports Calibration software calibration Initialization Properties Once you have identified the available devices use the initialization properties described in Table 6 Table 6 Initialization Properties Property Description Board Property Provides the means for the software to associate specific requests with a particular board it must be called before any other property This property loads a specified board s software support Specify the alias name assigned to th
18. a result it takes unique advantage of the Windows architecture to achieve maximum performance By using sophisticated software buffering part of the DT Open Layers standard and the PCI bus USB bus or DMA capabilities of the hardware the software can achieve continuous throughput to or from memory at greater than 1 MHz Chapter 1 What You Need To use DTx EZ you need the following Pentium or higher based PC with a CD ROM drive and a minimum of 32 Mbytes of RAM One or more supported data acquisition boards Microsoft Windows 2000 or XP Microsoft Visual C 6 0 or Microsoft Visual Basic 6 0 Overview Installation DTx EZ is installed automatically when you install the device driver for the module Refer to the getting started manual for your module for more information Chapter 1 Adding DTx EZ Custom Controls to Your Project The following subsections describe how to add DTx EZ Custom Controls to e A Visual Basic 6 0 project this page e A Visual C 6 0 project page 11 Adding to a Visual Basic 6 0 Project Before you begin using the DT EZ add the DTx EZ Data Acquisition and DT Plotting Custom Controls and definition files Add the files DTACQ32 0CX DTPLOT32 0CX OLMEMDEFS BAS OLDADEFS BAS and OLDSPDEFS BAS to your project file as follows from Visual Basic 6 0 1 Select Project gt Components The Components dialog box appears 2 Click the Controls tab 3 Click DTAcq32 OLE Cus
19. all of the specific reference information for each of the properties methods functions subroutines error codes and Windows messages events xiii About this Manual xiv Organization of this Manual This manual is organized as follows Chapter 1 Overview provides an overview of DTx EZ Chapter 2 Using the DTx EZ Examples describes how to use the example programs provided with DTx EZ Chapter 3 Property Method Function and Subroutine Summary summarizes the properties methods functions and subroutines provided with DTx EZ Chapter 4 Programming Flowcharts provides programming flowcharts for using the properties methods functions and subroutines provided with DTx EZ Chapter 5 Software Architecture describes the architecture and concepts of DTx EZ software Chapter 6 Product Support describes how to get help if you have trouble using DTx EZ Appendix A Flowcharts for Substeps provides additional flowcharts for performing substeps required for an operation An index completes this document Conventions Used in this Manual The following conventions are used in this manual Notes provide useful information that requires special emphasis cautions provide information to help you avoid losing data or damaging your equipment and warnings provide information to help you avoid catastrophic damage to yourself or your equipment Items that you select or
20. and lower limits 167 set first line on 168 show hide lines on 168 yMax property 73 167 in setting plot y axis 188 yMin property 73 167 in setting plot y axis 188 Z zooming example of 28 Specifications are subject to change without notice All Keithley trademarks and trade names are the property of Keithley Instruments Inc All other trademarks and trade names are the property of their respective companies KEITHLEY A GREATER MEAS URE OF CON Fl DEN CE Keithley Instruments Inc Corporate Headquarters 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 www keithley com 12 04
21. detects an initial trigger post trigger source only the board scans the channel gain list a specified number of times determined by the MultiscanCount property then stops When the external retrigger occurs the process repeats The conversion rate of each channel in the scan is determined by the frequency of the A D sample clock refer to page 122 for more information on clock sources The conversion rate of each scan is determined by the period between retriggers therefore it cannot be accurately controlled The board ignores external triggers that occur while it is acquiring a scan of data Only retrigger events that occur when the board is waiting for a trigger are detected and acted on Some boards may generate a TriggerError event Internal Retrigger Mode Use internal retrigger mode if you want to accurately control both the period between conversions of individual channels in a scan and the period between each scan To determine if the subsystem supports internal retrigger mode use the GetSSCaps method specifying the OLSSC_SUP_RETRIGGER_INTERNAL capability If this method returns a non zero value the capability is supported Specify the retrigger mode as OL_RETRIGGER_INTERNAL using the RetriggerMode property The conversion rate of each channel in the scan is determined by the frequency of the A D sample clock refer to page 122 for more information on clock sources The conversion rate between scans is determined by the
22. e Analog event trigger page 127 e Digital event trigger page 127 e Timer event trigger page 127 and e Extra trigger page 127 Software Architecture To specify a post trigger source use the Trigger property refer to page 114 for more information To specify a pre trigger source use the PreTrigger property see page 115 for more information To specify a retrigger source use the ReTrigger property see page 121 for more information The following subsections describe these trigger sources Note that you cannot specify a trigger source for single value operations Software Internal Trigger Source A software trigger occurs when you start the operation internally the computer writes to the board to begin the operation To determine if the subsystem supports a software trigger use the GetSSCaps method specifying the capability OLSSC_SUP_SOFTTRIG If this method returns a non zero value the capability is supported External Digital TTL Trigger Source An external digital trigger is a digital TTL signal attached to the device To determine if the subsystem supports an external digital trigger use the GetSSCaps method specifying the capability OLSSC_SUP_EXTERNTRIG If this method returns a non zero value the capability is supported 125 Chapter 5 126 External Analog Threshold Positive Trigger Source An external analog threshold positive trigger is generally either an analog signal f
23. example prompts you for the board s name After the board is located a display allows you to monitor inputs and generate outputs A single value is continuously input and displayed in a text box and on the scroll bar as shown in Figure 9 Ei Single Value Jol x Input Output 10 Volts 10 Volts Channel jo Channel jo Gan ES Gain Figure 9 Monitoring Inputs and Outputs for a Single Value Operation 31 Chapter 2 A single value can also be output continuously You can change the output voltage setting by entering a new value in the text box or by adjusting the scroll bar Note The actual read and write rate is set to 100 ms by the timer control The clock timer control runs from the system clock 32 Using the DTx EZ Examples About Trigger Example This example abouttrig vbp or abouttrig mdp samples a single analog input channel to memory and plots the data on screen using pre defined buffer and frequency settings until the main trigger event After the trigger the example samples the channel for one second and then stops You could use this example to collect data before and after a specific event trigger occurs In this example the marker is used to show the first point collected after the trigger event so you can see the triggering point This example also demonstrates using the stripchart mode to plot entire buffers of data rather than single points one at a time Clic
24. followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name Specify the buffer wrapping mode if none 0 buffers C WrapMode Property are not reused if no buffers are found on the ready queue if multiple 1 completed buffers are taken from the done queue and continuously reused when no buffers are found on the ready queue if single 2 lt a single buffer is continuously reused Use the AllocBuffer function o DmAllocBuffer to AllocBuffer Function allocate a buffer of samples where each sample is 2 olDmAllocBuffer or bytes use the CallocBuffer function CallocBuffer Function olDmCallocBuffer to allocate a buffer of samples of a specified size o DmCallocBuffer y Fill the buffer Y SetValidSamples Function Specify the valid number of data points in the buffer olDaSetValidSamples v Queue Property Put the buffer onto the ready queue A minimum of three buffers is recommended for continuous input operations if you are not using single wrap mode Allocate more buffers 177 Appendix A 178 Deal with Events and Buffers for Input Operations Yes The following error events can occur Get error Report the error OverrunError or TriggerError event In this flowchart a function or subrout
25. frequency of the internal retrigger clock on the board You specify the frequency on the internal retrigger clock using the RetriggerFreq property Software Architecture When it detects an initial trigger pre trigger source or post trigger source the board scans the channel gain list a specified number of times determined by the MultiscanCount property then stops When the internal retrigger occurs determined by the frequency of the internal retrigger clock the process repeats It is recommended that you set the retrigger frequency as follows Min Retrigger of CGL entries x of CGLs per trigger 2 us Period A D sample clock frequency Max Retrigger 1 Frequency Min Retrigger Period For example if you are using 512 channels in the channel gain list CGL scanning the channel gain list 256 times every trigger or retrigger and using an A D sample clock with a frequency of 1 MHz set the maximum retrigger frequency to 7 62 Hz since 7 62 Hz 1 512 256 2 us 1 MHz Retrigger Extra Mode Use retrigger extra mode if you want to accurately control the period between conversions of individual channels and retrigger the scan on a specified retrigger source the retrigger source can be any of the supported trigger sources To determine if the subsystem supports retrigger extra mode use the GetSSCaps method specifying the OLSSC_SUP_RETRIGGER_EXTRA capability If this method returns a non zero value t
26. if subsystem supports cascading OLSSC_SUP_CTMODE_ COUNT Non zero if subsystem supports event counting mode OLSSC_SUP_CTMODE_RATE Non zero if subsystem supports rate generation continuous pulse output mode OLSSC_SUP_CTMODE_ ONESHOT Non zero if subsystem supports single one shot mode OLSSC_SUP_CTMODE_ ONESHOT_RPT Non zero if subsystem supports repetitive one shot mode Counter Timer Pulse Output Types OLSSC_SUP_PLS_HIGH2LOW Non zero if subsystem supports high to low output pulses OLSSC_SUP_PLS_LOW2HIGH Non zero if subsystem supports low to high output pulses 55 Chapter 3 56 Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Counter Timer Gates OLSSC_SUP_GATE_NONE Non zero if subsystem supports an internal software gate type OLSSC_SUP_GATE_HIGH LEVEL Non zero if subsystem supports high level gate type OLSSC_SUP_GATE_LOW LEVEL OLSSC_SUP_GATE_HIGH EDGE OLSSC_SUP_GATE_LOW EDGE Non zero if subsystem supports low level gate type Non zero if subsystem supports high edge gate type Non zero if subsystem supports low edge gate type OLSSC_SUP_GATE_LEVEL Non zero if subsystem supports level change gate type OLSSC_SUP_GATE_HIGH LEVEL_DEBOUNCE Non zero if subsystem supports high level gate type with input debounce
27. internal 122 155 support for 55 122 155 maximum internal frequency 123 155 minimum internal frequency 123 155 Index quantity of extra 55 124 157 set parameters for C T operations 183 specifying 174 clock divider maximum supported 124 156 minimum supported 124 156 ClockDivider property 60 in C T operations 183 in frequency measurement operations 142 in rate generation operations 144 in setting clock parameters 174 with external clock 123 156 ClockSource property 60 142 example using 23 in C T operations 183 in frequency measurement operations 140 142 in setting clock parameters 174 with external clock 123 156 with internal clock 122 155 color set grid line s 168 set maker line s 169 set plot line s 167 Config method 61 95 in continuous buffered input operations 80 in continuous buffered output operations 82 in event counting operations 83 in frequency measurement operations 86 142 143 in pulse output operations 88 in single value operations 77 configure a subsystem 95 continue an operation 184 Continue method 61 184 in continuous operations 114 in event counting operations 139 in rate generation operations 145 in repetitive one shot operations 152 continuous post trigger mode 114 continuous A D example of 29 continuous about trigger operation 116 support for 50 continuous about trigger operation support for 117 continuous FFT example 40 continuous operation 113 performing input 79
28. measurement operations 143 in one shot operations 149 in pulse output operations 88 209 Index 210 in rate generation operations 145 in repetitive one shot operations 152 starting point set for plot 167 stop a simultaneous operation 165 an operation 98 184 Stop method 61 98 184 example using 24 27 41 in continuous operations 113 in event counting operations 139 in rate generation operations 145 in repetitive one shot operations 152 in simultaneous operations 165 stripchart mode 168 enable disable 168 example using 27 33 41 StripChartMode property 70 168 in setting plot re operation parameters 186 StripChartSize property 70 168 in setting plot re operation parameters 186 style set grid line s 168 set plot line s 167 SubSysElement property 57 94 in continuous buffered input operations 79 in continuous buffered output operations 81 in event counting operations 83 in frequency measurement operations 85 in pulse output operations 87 in single value operations 77 subsystem configuring 95 defined 94 pre starting 164 put on simultaneous start list 164 quantity available 95 set parameters 172 subsystem handle 94 SubSystem property 57 94 in continuous buffered input operations 79 in continuous buffered output operations 81 in event counting operations 83 in frequency measurement operations 85 in pulse output operations 87 in single value operations 77 SubSystemList property 48 95 SubSysType prope
29. not included in this manual io To launch this online help double click the DTx EZ help icon in the KUSB Series program group or folder 13 Chapter 1 14 Using the DTx EZ Examples About the Examples ereire imiraa eens 16 A D Burst Examiple sps cerise eepes sete cerien s oeeee ees 20 DAC Waveform Generator Example 000220005 25 Continuous A D Example 0 0 0 eee eee 29 Single Value Example 6 pestina c cece cee eens 31 About Trigger Example 0 06 66 c cee nee eee 33 Digital I O Example sieicc e084 toed ae tke tad kiida 35 DDE Server and Client Examples 00 0000 e eee 37 Waveform Generator Example n a aanas sannan eee 39 Continuous FFT Example sessie siae a a S 40 Chartlt Example eiee ieee ilies neea teehee ee e 41 Scope Example s resci ayes sce doen dab alee eres Beans 42 15 Chapter 2 16 About the Examples DTx EZ provides the software tools to create Visual Basic and Visual C data acquisition applications quickly and easily A comprehensive set of examples shows you how to use DTx EZ s Data Acquisition and DT Plotting Custom Controls in the Visual Basic or Visual C environment If your needs are simple choose one of the example programs DTx EZ will perform data acquisition right out of the box Since all example source code is included you can easily modify the examples to suit your needs combine two or more examples or extend the exam
30. only for one shot and repetitive one shot mode refer to page 138 for more information on these modes To determine if the subsystem supports a high edge external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_HIGH_EDGE capability If this method returns a non zero value the capability is supported Any Level Gate Type A level gate type enables a counter timer operation on the transition to any level Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a level external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_LEVEL capability If this method returns a non zero value the capability is supported 159 Chapter 5 High Level Debounced Gate Type A high level debounced gate type enables a counter timer operation when the external gate signal is high and debounced Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a high level debounced external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_HIGH_LEVEL_DEBOUNCE capability If this method returns a non zero value the capability is supported Low Level Debounced Gate Type A low level debounced gate type enables a co
31. sets the actual clock divider as closely as possible to the number specified lt y Trigger Property Yy Yes Specify the source of the trigger to start post trigger acquisition or output or for A D subsystems only to stop pre trigger acquisition if used Refer to your device driver documentation for details For A D subsystems Using pre or about trigger only specify the PreTrigger Property trigger usually 174 software to start the pre trigger or about trigger acquisition Flowcharts for Substeps Set Up Triggered Scan 4 TriggeredScan Property Enable triggered scan mode Specify the retrigger mode OL_RETRIGGER_ INTERNAL internal retrigger clock is the retrigger any supported trigger source is initial trigger OL_RETRIGGER_SCAN_PER_TRIGGER retrigger source same as initial trigger source or OL_RETRIGGER_EXTRA external retrigger source is the retrigger any supported trigger source is the initial trigger v RetriggerMode Property Yes Set the frequency of the RetriggerFreq Property retrigger clock The driver sets the actual frequency as closely as possible to the number specified Using interna retrigger mode Specify the retrigger source Refer to your device driver documentation for details Using re trigger extra mode ReTrigger Property Specify th
32. shot operations 152 in simultaneous operations 165 about trigger continuous operation 116 support for 50 117 example using 33 allocate a buffer 128 a simultaneous start list 164 AllocBuffer function 65 128 in inprocess buffer transfer 180 in input buffering 176 in output buffering 177 analog event trigger 127 support for 55 127 application creating 12 creating a device independent 94 asynchronous operations support for 51 Index B BackColor property in setting plot appearance 185 binary encoding support for 54 99 board initializing and specifying 93 listing available at runtime 93 quantity installed 93 query for processor 57 Board property 57 93 in continuous buffered input operations 79 in continuous buffered output operations 81 in event counting operations 83 in frequency measurement operations 85 in pulse output operations 87 in single value operations 77 BoardList property 48 76 93 buffer 128 allocating 128 events 178 identify data in for plotting 166 multiple wrap mode support 51 135 removing from done queue 133 set up for input 176 set up for output 177 single wrap mode support 51 135 specify quantity of channels in for plotting 166 195 Index 196 support for 51 128 transfer data from inprocess 180 wrap 134 write to inprocess support 51 131 Buffer property 73 in plotting control operations 4 89 BufferDone event 118 131 133 in buffer input operations 178 in buffer output
33. sssi ciaccigee cteiceiec essed aegalcas 20 DAC Waveform Generator Example 00 0005 25 Continuous A D Example 0 00 e ee eee ee 29 Single Value Example so s0s00s 00 c1giecieadeseacesean es 31 About Trigger Example 00 000 e eee eee eee 33 Digital I O Example 20 breiir ieii 35 DDE Server and Client Examples 60 000s e eee 37 Waveform Generator Example 00020000 39 Continuous FFT Example 2 0 66 nann rreran 40 Chartlt Example oo2 c 00s0s00ssg00 saga es bean aveu cesdu ce 41 Seope Examples i scec sie deve cewidad ane neha degen ids 42 Chapter 3 Property Method Function and Subroutine SUMMANY o c0 bee ee eee eee Ce eel oat 45 Introductiony erer yi bya deeds be eee ee Lage 46 Data Acquisition Custom Control 000 47 Information Properties and Methods 47 Initialization Properties 0 000000008 57 Configuration Properties and Functions 58 Operation Properties Methods Functions and SUDFOUETES eneee segue a eave ote Red eed ane wgiaed ins 61 Data Management DLLs 06 64 Buffer Management Functions and Subroutines 64 Conversion Functions and Subroutines 67 DT Plot Custom Control auauna 69 Plot Appearance 4 5400 Svea vie ds wis geerte eei eei 69 Contents Plot Pre Display Operational Parameters 70 Grid
34. the equipment is operated within its specifications and operating limits and for en suring that operators are adequately trained Operators use the product for its intended function They must be trained in electrical safety procedures and proper use of the instru ment They must be protected from electric shock and contact with hazardous live circuits Maintenance personnel perform routine procedures on the prod uct to keep it operating properly for example setting the line volt age or replacing consumable materials Maintenance procedures are described in the manual The procedures explicitly state if the operator may perform them Otherwise they should be performed only by service personnel Service personnel are trained to work on live circuits and perform safe installations and repairs of products Only properly trained ser vice personnel may perform installation and service procedures Keithley products are designed for use with electrical signals that are rated Measurement Category I and Measurement Category II as described in the International Electrotechnical Commission IEC Standard IEC 60664 Most measurement control and data I O sig nals are Measurement Category I and must not be directly connect ed to mains voltage or to voltage sources with high transient over voltages Measurement Category II connections require protection for high transient over voltages often associated with local AC mains connections Assume
35. to transfer data from an inprocess Return to the top of buffer page 178 Yes Wait for message 179 Appendix A Transfer Data from an Inprocess Buffer In this flowchart a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name C QueueSize Property D AllocBuffer Function olDmAllocBuffer or CallocBuffer Function o DmCallocBuffer FlushFromBufferlnProcess Subroutine ol DaFlushFromBufferlnprocess y See page 178 to deal with the buffers 180 Determine the number of buffers on the inprocess queue at least one buffer must be on the inprocess queue to perform this operation Use the AllocBuffer function o DmAllocBuffer to allocate a buffer of samples where each sample is 2 bytes use the CallocBuffer function o DmCallocBuffer to allocate a buffer of samples of a specified size Copy the data from the inprocess buffer to the allocated buffer for immediate processing A BufferDone event occurs when the operation completes Flowcharts for Substeps Deal with Events and Buffers for Output Operations Yes The following error events can occur Report the error UnderrunError or TriggerError Get error event In this flowchart a function or
36. trigger event occurs When the post trigger event occurs post trigger acquisition begins on each clock pulse of the A D sample clock refer to page 122 for more information on clock sources The board wraps to the beginning of the channel list and acquires post trigger data continuously 117 Chapter 5 118 Chano Chano Chano Chan0 Chano Chan 0 Chan 1 Chan 1 Chan 1 Chan 1 Chan 1 Chan 1 wo PANET Sample a Clock Pre trigger data acquired Post trigger data acquired p lt a Pre trigger event occurs Post trigger event occurs Figure 26 Continuous About Trigger Mode As your buffers fill during the pre trigger state the buffers are placed on the done queue and a PreTriggerBufferDone event occurs Buffers filled during the post trigger state are placed on the done queue and a BufferDone event occurs Check the valid number of samples in the buffers before using them since the last buffer filled prior to switching to the post trigger state may be only partially full Triggered Scan Mode In triggered scan mode the board scans the entries in a channel gain list a specified number of times when it detects the specified trigger source acquiring the data for each entry that is scanned To determine if the subsystem supports triggered scan mode use the GetSSCaps method specifying the OLSSC_SUP_TRIGSCAN capability If this method returns a non zero value
37. type are shown in bold Property method function and subroutine names also appear in bold Code fragments appear in courier font About this Manual In syntax items inside square brackets are optional In syntax a vertical bar between braces indicates that you must choose between two or more items You must choose an item unless all of the items are also enclosed in curly brackets For example True False indicates that you must select one of these choices When navigating the screens an instruction such as Configure gt Board means to select Board from the drop down menu under Configure Related Information Refer to the following documentation for more information on using DTx EZ DTx EZ Online Help This Windows help file is located in the same program group as the DTx EZ software and contains all of the specific reference information for each of the properties methods subroutines functions error codes and Windows messages events provided by DTx EZ Refer to page 13 for information on how to launch this help file Device Driver documentation for your board This documentation describes the capabilities supported by the device driver for your board Refer to this documentation as you develop application programs using DTx EZ User manual for your data acquisition board This manual describes the capabilities of the hardware as well as how to set up and install your board For Visual Basic a
38. use this pulse output signal as an external digital TTL trigger to start analog input analog output or other operations To determine if the subsystem supports one shot mode use the GetSSCaps method specifying the capability OLSSC_SUP_CTMODE_ONESHOT If this method returns a non zero value the capability is supported To specify a one shot operation use the CTMode property specifying the repetitive one shot parameter 3 Software Architecture Specify the C T clock source for the operation In one shot mode the internal C T clock source is more useful than an external C T clock source refer to page 154 for more information on specifying the C T clock source Specify the polarity of the output pulse high to low transition or low to high transition and the duty cycle of the output pulse refer to page 162 for more information Note In the case of a one shot operation use a duty cycle as close to 100 as possible to output a pulse immediately Using a duty cycle less then 100 acts as a pulse output delay Also specify the gate type that triggers the operation refer to page 157 for more information To start a one shot pulse output operation use the Start method When the one shot operation is triggered determined by the gate input signal a single pulse is output then the one shot operation stops All subsequent clock input signals and gate input signals are ignored Use software to specify the count
39. using the following equation Frequency Number of Events Duration of the Windows Timer When the operation is complete the MeasureDone event is generated Use the LongtoFreq Param macro described in DTx EZ online help to get the measured frequency value Figure 34 shows an example of a frequency measurement operation Three events are counted from the clock input signals during a duration of 300 ms The frequency is 10 Hz 3 3 3 Events Counted LI LI Lot External C T lt lt eal oe I Duration over which the npursgna frequency is measured 300 ms frequency measurement frequency starts measurement sto Figure 34 Example of Frequency Measurement 141 Chapter 5 Using a Pulse of a Known Duration If you need more accuracy than the Windows timer provides you can connect a pulse of a known duration to the external gate input of a counter timer configured for event counting refer to the boards user manuals for wiring details The following example describes how to use DTx EZ to measure frequency using two C T subsystems one that generates a variable width one shot pulse as the gate input to a second C T subsystem configured for event counting mode 1 Set up one C T subsystem for one shot mode as follows a Use the CTMode function specifying the one shot parameter 2 b For this C T subsystem specify the clock source with the ClockSource property the c
40. when no more data is available 113 Chapter 5 114 Some subsystems also allow you to pause the operation using the Pause method and to resume the paused operation using the Continue method To determine if pausing is supported use the GetSSCaps method specifying the OLSSC_SUP_PAUSE capability If this method returns a non zero value the capability is supported The following continuous modes are supported by DTx EZ continuous post trigger continuous pre trigger and continuous about trigger These modes are described in the following subsections Continuous Post Trigger Mode Use continuous post trigger when you want to acquire or output data continuously when a trigger occurs To determine if the subsystem supports continuous post trigger operations use the GetSSCaps method specifying the capability OLSSC_SUP_CONTINUOUS If this method returns a non zero value the capability is supported For continuous post trigger mode specify the operation mode as continuous 0 using the DataFlow property Use the Trigger property to specify the trigger source that starts the operation Refer to page 124 for more information on supported trigger sources When the post trigger occurrence is detected the board cycles through the channel list acquiring and or outputting the value for each entry in the channel list this process is defined as a scan The board then wraps to the start of the channel list and repeats
41. 161 support for 56 161 low level 158 support for 56 158 low level debounced 160 support for 56 160 set for cascaded clocks 156 set parameters 183 GateType property 60 157 in C T operations 183 in frequency measurement operations 140 142 143 with software gate 158 generate waveform example of 25 Get Channel Range function 59 GetBufferSize function 66 GetDataBits function 66 GetDataWidth function 66 GetDevCaps method 48 76 95 GetErrorString function 66 GetMaxSamples function 66 GetSimultaneousStartList function 63 164 GetSingle Value method 61 example using 41 in single value operations 78 112 GetSSCaps method 49 76 GetSSCapsEx method 49 76 GetTimeDateStamp function 66 GetValidSamples function 67 in buffer input operations 178 grid 168 define first axes lines 168 enable disable relative line spacing 168 set color 168 set line s style 168 set parameters 189 show hide lines 168 space lines on 168 GridAutoScale property 71 168 in setting grid parameters 189 GridColor property 71 168 GridStyle property 71 168 in setting grid parameters 189 GridXOn property 71 168 in setting grid parameters 189 201 Index 202 GridXSpacing property 71 168 in setting grid parameters 189 GridXStart property 71 168 in setting grid parameters 189 GridYOn property 71 168 in setting grid parameters 189 GridYSpacing property 71 168 in setting grid parameters 189 GridYStart property 71 168 in
42. 22 provides an overview of the steps required to perform a pulse output operation including rate generation single one shot or repetitive one shot Many steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes Select the board with the Board property Select a C T subsystem with the SubSystem property or use the SubSysType and SubSysElement properties Yy Set the cascade mode using the CascadeMode property vy Set up the clocks and gates see page 183 y Specify the counter timer mode using the CTMode property Go to the next page N A 1 Specify 1 for rate generation continuous pulse output 2 for single one shot or 3 for repetitive one shot Figure 22 Performing a Pulse Output Operation 87 Chapter 4 Continued from previous page gt Specify the output pulse type using the PulseType property Specify the duty cycle of the output pulse using the PulseWidth property f Configure the subsystem using the Config method Yy Start the operation using the Start method v Stop the operation see page 184 Figure 22 Performing a Pulse Output Operation cont 88 Programming Flowcharts Plotting Control Operations The flowchart in
43. 6 Specifying Synchronous Digital I O Values in the Channel List If supported you can set up a synchronous digital I O list this feature is useful if you want to write a digital output value to dynamic digital output channels when an analog input channel is sampled To determine if the subsystem supports synchronous dynamic digital output operations use the GetSSCaps method specifying the OLSSC_SUP_SYNCHRONOUSDIGITALIO capability If this method returns a non zero value the capability is supported Use the SyncDIOUsage property to enable or disable synchronous dynamic digital output operation for a specified subsystem Once you enable a synchronous digital output operation specify the values to write to the synchronous dynamic digital output channels using the DIOList property for each entry in the channel list To determine the maximum digital output value that you can specify use the GetSSCaps method specifying the OLSSC_MAXDIGITALIOLIST_VALUE capability As each entry in the channel list is scanned the corresponding value in the synchronous digital I O list is output to the dynamic digital output channels Consider the following example Software Architecture Channel List Synchronous Entry Channel Digital I O Value Description 0 7 1 Sample channel 7 and output a value of 1 to the dynamic digital output channels 1 5 1 Sample channel 5 and output a value of 1 to the dynamic digital output channe
44. 74 triggered scan 118 setting up 175 support for 52 118 support for scan per trigger mode 52 119 TriggeredScan property 58 118 example using 24 in setting up triggered scan 175 TriggerError event 120 in buffer input operations 178 in buffer output operations 181 in retrigger extra mode 122 troubleshooting service and support procedure 193 troubleshooting checklist 192 twos complement encoding support for 54 99 U UpdateMode property 73 167 in plotting control operations 89 V ValueToVolts function 68 211 Index 212 Visual Basic project adding custom controls to 10 Visual C project adding custom controls to 11 VoltsToOutput subroutine 68 VoltsTo Value function 68 W waveform example of generating 25 Waveform Generator example 39 what you need 8 width set plot line s 167 Window subroutine 68 Windows timer using 140 wrap mode 134 multiple support 51 135 single support 51 135 WrapMode property 58 in input buffering 176 in output buffering 177 with buffer wrap mode none 134 with multiple buffer wrap mode 135 with single buffer wrap mode 135 X xAutoScale property 72 167 x axis automatic scaling 167 set first line on 168 set length of 167 show hide lines on 168 xLength property 72 167 xScale property 72 167 169 in setting plot x axis 187 xStart property 72 167 Y yAutoScale property 73 167 in setting plot y axis 188 y axis automatic scaling 167 define upper
45. 9 76 111 Flush method 62 134 FlushFromBufferInProcess subroutine in inprocess buffer transfer 180 with inprocess queue 130 FlushFromBufferInprocess subroutine with done queue 132 ForceRepaint property 73 167 in plotting control operations 89 ForeColor property in setting plot appearance 185 FreeBuffer subroutine 66 134 frequency measurement operation 140 performing 85 support for 140 Frequency property 60 in C T operations 183 in frequency measurement operations 142 in rate generation operations 144 in setting clock parameters 174 with internal clock 122 155 G gain 109 list available 109 list available during runtime 110 programmable support 53 109 quantity available during runtime 110 quantity of selections 53 109 specify for one or more channels 109 specify for single channel 109 GainList property 59 110 in setting channel parameters 173 Gain Values property 49 76 110 Index gap free continuous operation with dual DMA support 51 136 continuous operation with no DMA support 51 136 continuous operation with single DMA support 51 136 input data 134 gate 157 high edge 159 support for 56 159 high edge debounced 160 support for 56 161 high level 158 support for 56 158 high level debounced 160 support for 56 160 internal software 158 support for 56 158 level 159 support for 56 159 level debounced 161 support for 56 161 low edge 159 support for 56 159 low edge debounced
46. CopySingleChannelFromBuffer Subroutine CopyChannelToBuffer Subroutine Creates a buffer object of a specified number of samples where each sample is 2 bytes Creates a buffer object of a specified number of samples of a specified size Copies one selected channel s data from a buffer to the specified array Copies one selected channel s data from a buffer to the specified array Copies one selected channel s data from a buffer to the specified array Copies one selected channel s data from a buffer to the specified array CopyLongChannelToBuffer Subroutine Copies one selected channel s data from a buffer to the specified array These functions were instituted for Visual Basic users since direct buffer access cannot be achieved Visual C users can access the buffer directly with ol DmGetBufferPtr 65 Table 9 Buffer Management Functions and Subroutines cont Functions and Subroutines Description CopySingleChannelToBuffer Subroutine Copies one selected channel s data from a buffer to the specified array CopyFromBuffer Subroutine Copies data from a buffer to the specified array CopyToBuffer Subroutine Copies data from an array to the specified buffer FreeBuffer Subroutine olDmFreeBuffer Deletes a buffer object olDmGetBufferPtr Gets a pointer to the buffer data GetBufferSize Function olDmGetBufferSize Gets the p
47. Figure 23 provides an overview of the steps required to plot data Many steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes se the UpdateMode property to FALSE l Set up the plots pre operation parameters Set up the plot s appearance see page 186 see page 185 Set up the plot s x axis IERS Set up the plot s y axis see page 187 see page 188 Set up the grid s appearance Set the ForceRepaint property see page 189 y Plot the data with either the Buffer or the SinglePoint property E y Set the UpdateMode property to True v Set up the mouse and marker parameters see page 190 Vv Go to the next page D Figure 23 Plotting Data 89 Chapter 4 Continued from previous page No 90 Change viewing area Set the UpdateMode property to False Set up the grid s appearance see page 189 Set up the plot s x axis see page 187 Set up the plot s y axis see page 188 Set the UpdateMode property to True 4 v Yes Plot new data Set the UpdateMode property to False Return to the amp symbol on page 89 Figure 23 Plotting Data cont
48. Getting Started Manual DTXEZ 903 01 Rev A January 2005 i E a USA qu pme nt po L INET An Interworld Highway LLC Company A GREATER MEASURE OF CONFIDENCE WARRANTY Keithley Instruments Inc warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment Keithley Instruments Inc warrants the following items for 90 days from the date of shipment probes cables rechargeable batteries diskettes and documentation During the warranty period we will at our option either repair or replace any product that proves to be defective To exercise this warranty write or call your local Keithley representative or contact Keithley headquarters in Cleveland Ohio You will be given prompt assistance and return instructions Send the product transportation prepaid to the indicated service facil ity Repairs will be made and the product returned transportation prepaid Repaired or replaced products are warranted for the bal ance of the original warranty period or at least 90 days LIMITATION OF WARRANTY This warranty does not apply to defects resulting from product modification without Keithley s express written consent or misuse of any product or part This warranty also does not apply to fuses software non rechargeable batteries damage from battery leak age or problems arising from normal wear or failure to follow instructions THIS WARRANTY IS IN LIEU OF ALL O
49. ION software programmable resolution OLSSC_NUMRESOLUTIONS Number of different resolutions that you can program for the subsystem Data OLSSC_SUP_BINARY Non zero if subsystem supports Encoding binary encoding OLSSC_SUP_2SCOMP Non zero if subsystem supports twos complement encoding Triggers OLSSC_SUP_SOFTTRIG Non zero if subsystem supports internal software trigger OLSSC_SUP_EXTERNTRIG Non zero if subsystem supports external digital TTL trigger OLSSC_SUP_ THRESHTRIGPOS Non zero if subsystem supports positive analog threshold trigger OLSSC_SUP_ THRESHTRIGNEG Non zero if subsystem supports negative analog threshold trigger OLSSC_SUP_ Non zero if subsystem supports ANALOGEVENTTRIG analog event trigger OLSSC_SUP_ Non zero if subsystem supports DIGITALEVENTTRIG digital event trigger OLSSC_SUP_ TIMEREVENTTRIG Non zero if subsystem supports timer event trigger OLSSC_ NUMEXTRATRIGGERS Number of extra trigger sources supported Property Method Function and Subroutine Summary Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Clocks OLSSC_SUP_INTCLOCK Non zero if subsystem supports internal clock OLSSC_SUP_EXTCLOCK Non zero if subsystem supports external clock OLSSC_NUMEXTRACLOCKS Number of extra clock sources Counter Timer Modes OLSSC_SUP_CASCADING Non zero
50. If this method returns a non zero value the capability is supported Specify the clock source as internal 0 using the ClockSource property Then use the Frequency property to specify the frequency at which to pace the operation Software Architecture To determine the maximum frequency that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MAXTHROUGHPUT capability To determine the minimum frequency that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MINTHROUGHPUT capability Note According to sampling theory Nyquist Theorem you should specify a frequency for an A D signal that is at least twice as fast as the input s highest frequency component For example to accurately sample a 20 kHz signal specify a sampling frequency of at least 40 kHz Doing so avoids an error condition called aliasing in which high frequency input components erroneously appear as lower frequencies after sampling External Clock Source The external clock is a clock source attached to the board that paces data acquisition or output for each entry in the channel gain list This clock source is useful when you want to pace at rates not available with the internal clock or if you want to pace at uneven intervals To determine if the subsystem supports an external clock use the GetSSCaps method specifying the OLSSC_SUP_EXTCLOCK capability If this method returns a non zero value the capabili
51. Input Operation cont Programming Flowcharts Continuous Buffered Output Operations The flowchart in Figure 19 provides an overview of the steps required to perform a continuous buffered analog output or digital output operation Many steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes Select the board with the Board property Specify the subsystem to perform the operation with the SubSystem property or use the SubSysType and SubSysElement properties Select continuous data flow by setting the DataFlow property to continuous 0 v Set the DMA channel usage using the DmaUsage property y Set the subsystem parameters see page 172 y Set up the channel list and channel parameters see page 173 y C Go to the next page Figure 19 Performing a Continuous Buffered Output Operation 81 Chapter 4 Continued from previous page Set up the clocks and triggers see page 181 v Set up buffering see page 177 OES A Configure the D A or DOUT subsystem using the Config method y Start the operation with the Start method y Deal with events and buffers see page 181 Stop the operation
52. SCaps method specifying the OLSSC_SUP_GATE_HIGH_LEVEL capability If this method returns a non zero value the capability is supported Low Level Gate Type A low level external gate type enables a counter timer operation when the external gate signal is low and disables the counter timer operation when the external gate signal is high Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a low level external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_LOW_LEVEL capability If this method returns a non zero value the capability is supported 158 Software Architecture Low Edge Gate Type A low edge external gate type triggers a counter timer operation on the transition from the high level to the low level falling edge Note that this gate type is used only for one shot and repetitive one shot mode refer to page 151 for more information on these modes To determine if the subsystem supports a low edge external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_LOW_EDGE capability If this method returns a non zero value the capability is supported High Edge Gate Type A high edge external gate type triggers a counter timer operation on the transition from the low level to the high level rising edge Note that this gate type is used
53. THER WARRANTIES EXPRESSED OR IMPLIED INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES NEITHER KEITHLEY INSTRUMENTS INC NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS INC HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES SUCH EXCLUDED DAMAGES SHALL INCLUDE BUT ARE NOT LIMITED TO COSTS OF REMOVAL AND INSTALLATION LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON OR DAMAGE TO PROPERTY KEITHLEY A GREATER MEASURE OF CONFIDENCE Keithley Instruments Inc Corporate Headquarters 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 www keithley com 12 04 DTx EZ Getting Started Manual 2005 Keithley Instruments Inc All rights reserved First Printing January 2005 Cleveland Ohio U S A Document Number DTXEZ 903 01 Rev A Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual The Revi sion Level letter increases alphabetically as the manual undergoes subsequent updates Addenda which are released between Revisions contain important change information that the user should incorporate immediately into the manual Addenda a
54. To display the first pair of markers set the MarkerH1On and the MarkerV10On properties to TRUE To display the second pair set the MarkerH2On and the MarkerV2On properties to TRUE To set the markers positions use the MarkerH1Pos and MarkerH2Pos properties for the horizontal markers and the MarkerV1Pos and the MarkerV2Pos properties for the vertical markers Note that the xScale property affects these positions For example if xScale is set to 10 setting MarkerH1Pos to 2 causes the marker to appear at the 20 unit spot If xScale is set to 15 setting MarkerH1Pos to 3 causes the marker to appear at the 45 unit spot Alternately you can use the MouseXPos and MouseYPos properties to set the markers positions with the mouse To change the markers color use the MarkerColor property This property affects all the markers Finally you can alter the data at each marker Setting a value in the MarkerV1Data or MarkerV2Data properties alters the value of the point covered by the marker to that value specified by its respective property MarkerV1Data or MarkerV2Data 169 Chapter 5 170 General Checklist Service and Support 191 Chapter 6 General Checklist Should you experience problems using DTx EZ perform the following steps 1 Read all the appropriate sections of this manual Make sure that you have added any Read This First information to your manual and that have used this information
55. You can choose to run the examples without connecting a signal source to the board You can run the examples as applications However if you wish to view or modify the source code for the examples open the associated VBP files from within Visual Basic see page 18 or open the associated MDP files from within Visual C see page 19 Note Before running the examples make sure the device driver for your data acquisition board has been installed Running the Examples as Applications If you wish to use them as tutorials to learn how DTx EZ operates you can run the examples as applications as follows 1 Start your operating system 2 Inthe start menu select the icon for the desired example from the DTx EZ program group 17 Chapter 2 Opening the Examples from within Visual Basic To customize the DTx EZ example code for your own application you must open the example s build file VBP from within Visual Basic as follows 1 Start your operating system and start Visual Basic 2 Choose File gt Open Project 3 Select the examples from the directory DTx EZ examples vb The examples have a VBP extension Table 1 Visual Basic Example Programs and Their VBP Files Example Directory A D Burst adburst adburst vbp DAC Waveform dacwave dacwave vbp Continuous A D contdisp contdisp vbp Single value sv sv vbp Digital I O dio dio vbp DDE Server dde
56. _FILTERPERCHAN 54 111 OLSSC_SUP_GAPFREE_DUALDMA 51 136 OLSSC_SUP_GAPFREE_NODMA 51 136 OLSSC_SUP_GAPFREE_SINGLEDM A 51 136 OLSSC_SUP_GATE_HIGH_EDGE 56 159 OLSSC_SUP_GATE_HIGH_EDGE DEBOUNCE 56 161 OLSSC_SUP_GATE_HIGH_LEVEL 56 158 OLSSC_SUP_GATE_HIGH_LEVEL DEBOUNCE 56 160 OLSSC_SUP_GATE_LEVEL 56 159 OLSSC_SUP_GATE_LEVEL DEBOUNCE 56 161 OLSSC_SUP_GATE_LOW_ EDGE 56 139 OLSSC_SUP_GATE_LOW_EDGE DEBOUNCE 56 161 OLSSC_SUP_GATE_LOW_LEVEL 56 158 OLSSC_SUP_GATE_LOW_LEVEL DEBOUNCE 56 160 OLSSC_SUP_GATE_NONE 56 158 OLSSC_SUP_INPROCESS_FLUSH 51 131 OLSSC_SUP_INTCLOCK 55 122 155 OLSSC_SUP_INTERRUPT 56 135 OLSSC_SUP_PAUSE 51 OLSSC_SUP_PLS_HIGH2LOW 55 162 205 Index 206 OLSSC_SUP_PLS_LOW2HIGH 55 162 OLSSC_SUP_POSTMESSAGE 51 OLSSC_SUP_PROCESSOR 57 OLSSC_SUP_PROGRAMGAIN 53 109 OLSSC_SUP_RANDOM_CGL 52 103 OLSSC_SUP_RANGEPERCHANNEL 54 108 OLSSC_SUP_RETRIGGER_EXTRA 52 T21 OLSSC_SUP_RETRIGGER_ INTERNAL 52 120 OLSSC_SUP_RETRIGGER_SCAN_ PER_TRIGGER 52 119 OLSSC_SUP_SEQUENTIAL_CGL 52 103 OLSSC_SUP_SIMULTANEOUS_SH 53 103 OLSSC_SUP_SINGLEENDED 53 101 OLSSC_SUP_SINGLEVALUE 50 112 OLSSC_SUP_SOFTTRIG 54 125 OLSSC_SUP_SWCAL 57 OLSSC_SUP_SWRESOLUTION 54 100 OLSSC_SUP_SYNCHRONOUS_ DIGITALIO 53 106 OLSSC_SUP_THRESHTRIGNEG 54 126 OLSSC_SUP_TIMEREVENTTRIG 55 127 OLSSC_SUP_TRIGSCAN 52 118 OLSSC_SUP_WRPMULTIPLE 51 135 OLSSC_SUP_WRPSINGLE 51 135 OLSSCE_MAXCLOCKDIVIDER 124
57. a pre trigger and a post trigger acquisition Software Architecture To determine if the subsystem supports continuous about trigger mode use the GetSSCaps method specifying the OLSSC_SUP_CONTINUOUS_ABOUTTRIG capability If this method returns a non zero value the capability is supported Specify the operation mode as continuous about trigger 5 using the DataFlow property The about trigger acquisition starts when the board detects the pre trigger source When it detects an external post trigger source the board stops acquiring pre trigger data and starts acquiring post trigger data Use the PreTrigger property to specify the pre trigger source that starts the pre trigger operation this is generally a software trigger and the Trigger property to specify the trigger source that stops the pre trigger acquisition and starts the post trigger acquisition Refer to page 124 and to your board driver documentation for supported pre trigger and post trigger sources The about trigger operation stops when the specified number of post trigger samples has been acquired or when you stop the operation Figure 26 illustrates continuous about trigger mode using a channel list of three entries channel 0 channel 1 and channel 2 In this example pre trigger analog input data is acquired on each clock pulse of the A D sample clock The board wraps to the beginning of the channel list and the acquisition repeats continuously until the post
58. al substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes Select the board with the Board property Specify the subsystem to perform the operation with the SubSystem property or use the SubSysType and SubSysElement properties Set the data flow with the DataFlow property Set the DMA channel usage using the DmaUsage property v Set the subsystem parameters see page 172 v Set up the channel list and channel parameters see page 173 C Go to the next page 1 Specify continuous 0 for post trigger operations continuous pre trigger 4 for continuous pre trigger operations or continuous about trigger 5 for continuous about trigger operations Figure 18 Performing a Continuous Buffered Input Operation 79 Chapter 4 80 d Continued from previous page Set up the clocks triggers and pre triggers see page 174 y If you want to use triggered scan mode set up the scan see page 175 y Set up buffering see page 176 v Configure the subsystem using the Config method v Start the operation with the Start method v Deal with events and buffers see page 178 y Stop the operation see page 184 Figure 18 Performing a Continuous Buffered
59. ale use the xScale property To set the x axis length use the xLength property Use yMin to set the y axis lowest possible value and yMax to set the y axis highest possible value Appearance You can affect the color style and width of the lines you use to plot data To change a line s color use the Palette property To change a line s style that is dashed dotted and so on use the LineStyle property To change a line s width use the LineWidth property You may also enable or disable two modes that affect how data is displayed overall if the system displays data while processing it Set the ForceRepaint property to TRUE if you want the system to redraw the entire display each time a data element changes Set the UpdateMode property to TRUE if you want the plot to reflect each element change Note In most cases you should set the UpdateMode property to FALSE while setting a display s parameters After setting the parameters change the UpdateMode property to TRUE Doing so helps avoid errors 167 Chapter 5 168 Stripchart Mode When plotting rapidly changing continuous data it may be easiest to use stripchart mode Typically the stripchart size is several times greater than the size of each buffer When the stripchart display reaches the maximum size the oldest data is removed from the left of the display and internal buffer to make room for the newest data on the right side of the plot di
60. all measurement control and data I O connections are for connection to Category I sources unless other wise marked or described in the Manual Exercise extreme caution when a shock hazard is present Lethal voltage may be present on cable connector jacks or test fixtures The American National Standards Institute ANSI states that a shock hazard exists when voltage levels greater than 30V RMS 42 4V peak or 60VDC are present A good safety practice is to ex pect that hazardous voltage is present in any unknown circuit before measuring Operators of this product must be protected from electric shock at all times The responsible body must ensure that operators are pre vented access and or insulated from every connection point In some cases connections must be exposed to potential human con tact Product operators in these circumstances must be trained to protect themselves from the risk of electric shock If the circuit is capable of operating at or above 1000 volts no conductive part of the circuit may be exposed Do not connect switching cards directly to unlimited power circuits They are intended to be used with impedance limited sources NEVER connect switching cards directly to AC mains When con necting sources to switching cards install protective devices to limit fault current and voltage to the card Before operating an instrument make sure the line cord is connect ed to a properly grounded power receptacle Inspect the
61. alysis This example also demonstrates how to configure a channel gain list and the A D subsystem for a data acquisition board You could use this example once your application is debugged to store actual data values When you run the example the Select Board dialog box appears The A D Buffer To File screen is shown in Figure 1 Eid DTx EZ A D Buffer To File DT2831 Jof x Configure Start Figure 1 A D Buffer To File Screen Follow these steps 1 Select Configure gt Board to select a board from the list 2 Select Configure gt CGL to set up your board s channel gain list The Channel Gain List Setup dialog box shown in Figure 2 appears 20 Using the DTx EZ Examples amp Channel Gain List Setup x Entry Channel Gain List Size p2 Channel 5 sac Figure 2 Setting Up a Channel Gain List During data acquisition the channel gain list automatically selects channel and gain values without compromising throughput You can configure the list with channel numbers and associated gains To set up the channel gain list perform the following steps a Select the list size and then choose channel and gain values for each entry in the list b After changing each item click Set Entry to confirm the setting c When you have completed the setup click Done to return to the main menu 21 Chapter 2 The screen shown in Figure 2 illustrates a 512 entry channel gain list that repeated
62. an overview of the steps required to perform a single value operation Some steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Select the board with the Board property Specify the subsystem to perform the Specify A D for an analog input subsystem D A operation with the SubSystem property for an analog output subsystem DIN for a digital or use the SubSysType and input subsystem or DOUT for a digital output SubSysElement properties subsystem y Specify a single value operation by setting the DataFlow property to 1 A Set the subsystem parameters see page 172 y Configure the subsystem using the Config method y Go to the next page Figure 17 Performing Single Value Operations 77 Chapter 4 Continued from previous page Acquire a single value using the GetSingleValue method Acquiring data Output a single value using the YOS PutSingleValue method Acquire outpu another value Figure 17 Performing Single Value Operations cont 78 Programming Flowcharts Continuous Buffered Input Operations The flowchart in Figure 18 provides an overview of the steps required to perform a continuous buffered analog input or digital input operation Many steps represent sever
63. and counter timer C T The features provided by each supported data acquisition board vary for a complete list of capabilities supported by your board refer to board s driver documentation The API provides a full set of functions to query and set all possible device capabilities The library hides device details and presents a consistent interface to each subsystem Provides Extensive Example Programs To get your application up and running quickly a comprehensive set of Visual Basic and Visual C example programs is provided You can use these examples as tutorials to learn how DTx EZ operates or you can modify one or more examples to form the basis of your own custom data acquisition application Source code is included so you can customize the examples to complete your Visual Basic or Visual C application Provides Multiple Board Support The DTx EZ is hardware independent You can add support for new boards without altering or recompiling code at the application level simply by adding a new DT Open Layers device driver You install the device driver separately in the Windows environment refer to your board and or device driver documentation for more information on installing device drivers The library functions are designed to fully support all board features Overview Provides High Performance DTx EZ was designed with an intimate knowledge of the Windows operating environment and the IBM PC computer system As
64. aneous GetSimultaneousStartList Creates a simultaneous start list Operations Function and returns a handle to it olDaGetSSList PutSubSysOnSSList Puts the specified subsystem on Subroutine the simultaneous start list olDaPutDassToSSList SimultaneousPreStart Simultaneously prestarts Subroutine performs setup operations on all olDaSimultaneousPreStart subsystems on the specified simultaneous start list SimultaneousStart Subroutine Simultaneously starts all olDaSimultaneousStart subsystems on the specified simultaneous start list ReleaseSimultaneousStartList Releases all subsystems from the olDaReleaseSSList simultaneous start list and removes the list itself 63 Chapter 3 64 Data Management DLLs In addition to the Data Acquisition Custom Control DTx EZ offers the following data management tools e Buffer management functions and subroutines page 64 and e Conversion functions and subroutines page 67 Buffer Management Functions and Subroutines The buffer management functions and subroutines form one of the basic elements of the DT Open Layers architecture They glue the various layers together The fundamental data object in DTx EZ is a buffer All functions that create manipulate and delete buffers are encapsulated in the data management portion of DTx EZ The buffer management functions and subroutines listed in Table 9 are intended for use by both application and system p
65. aps method specifying the OLSSC_SUP_GATE_LOW_EDGE_DEBOUNCE capability If this method returns a non zero value the capability is supported Level Debounced Gate Type ay A level debounced gate type enables a counter timer operation on the transition of any level of the external gate signal the signal is debounced Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a high edge debounced external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_LEVEL_DEBOUNCE capability If this method returns a non zero value the capability is supported 161 Chapter 5 162 Pulse Output Types and Duty Cycles DTx EZ defines the following pulse output types e High to low transitions The low portion of the total pulse output period is the active portion of the counter timer clock output signal To determine if the subsystem supports high to low transitions on the pulse output signal use the GetSSCaps method specifying the OLSSC_SUP_PLS_HIGH2LOW capability If this method returns a non zero value the capability is supported e Low to high transitions The high portion of the total pulse output period is the active portion of the counter timer pulse output signal To determine if the subsystem supports low to high transitions on the pulse output signal use the GetSSCa
66. as separate entities however they are nearly identical in functionality In Table 10 a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name For specific information about each of these functions and subroutines refer to the DTx EZ online help See page 13 for information on launching the online help file 67 Chapter 3 Table 10 Conversion Utilities Functions and Subroutines Description ValueToVolts Function Converts a value into a voltage value as a single precision value VoltsToOutput Subroutine olDspVoltsToOutput Converts input voltage values to an output buffer that is compatible with the current setting of the specified subsystem VoltsToValue Function Converts the specified voltage into units that are appropriate for the specified subsystem InputToVolts Subroutine olDspInputToVolts Converts a subsystem input buffer into the corresponding voltage values MagToDB Subroutine Converts the input buffer data into decibels dB olDspMagToDB RealFFT Subroutine Performs a Fast Fourier Transform FFT on the olDspRealFFT specified data buffer Window Subroutine olDspWindow Converts the input data buffer into floating point and applies the specified window 68 Property Method F
67. associated with the DT Plot Custom Control e Events have procedures that execute code when the specified data acquisition event occurs during runtime in the case of the Data Acquisition Custom Control or when the specified mouse or keyboard event occurs during runtime in the case of the DT Plot Custom Control Most OLE custom control events are based on user interactions Note however that the Data Acquisition Custom Control events are based on specific data acquisition events that could occur within your application Most of the Data Acquisition Custom Control events are used for either continuous acquisition operation or for error tracking All of the DT Plot Custom Control events are standard Microsoft events Refer to your Visual Basic or Visual C online help for more information about them Provides Function and Subroutine Libraries In addition to custom controls DTx EZ provides a library of DT Open Layers functions and subroutines for Visual Basic and for Visual C These libraries add facilities for managing buffers simultaneously starting multiple subsystems and performing FFT analysis Chapter 1 Follows Object Oriented Design For easy programming DTx EZ s Application Programming Interface API emphasizes polymorphism it uses nearly identical interface functions to communicate with each type of data acquisition subsystem analog input A D analog output D A digital input DIN digital output DOUT
68. cifying the OLSSC_SUP_RANGEPERCHANNEL capability If this method returns a non zero value the capability is supported To determine how many ranges the subsystem supports use the GetSSCaps method specifying the OLSSC_NUMRANGES capability To list the minimum and maximum ranges supported by the subsystem use the EnumSSCaps function specifying the OL_ENUM_RANGES capability During runtime use the MaxRange and MinRange properties to return the maximum and minimum voltage values or a range setting Use the MaxRange Values and MinRangeValues properties to list the maximum and minimum voltage range values available to the subsystem Use the numRanges property to list the number of available voltage ranges for the subsystem Use the Range property to specify the range for a subsystem Note The channel list is not used to set the range for a channel For older board models the range is jumper selectable and must be specified in the driver configuration dialog Software Architecture Gains The range divided by the gain determines the effective range for the entry in the channel list For example if your board provides a range of 10 V and you want to measure a 1 5 V signal specify a range of 10 V and a gain of 4 the effective input range for this channel is then 2 5 V 10 4 which provides the best sampling accuracy for that channel The way you specify gain depends on how you specified the channels as described i
69. connecting cables test leads and jumpers for possible wear cracks or breaks before each use When installing equipment where access to the main power cord is restricted such as rack mounting a separate main input power dis connect device must be provided in close proximity to the equip ment and within easy reach of the operator For maximum safety do not touch the product test cables or any other instruments while power is applied to the circuit under test ALWAYS remove power from the entire test system and discharge any capacitors before connecting or disconnecting cables or jump ers installing or removing switching cards or making internal changes such as installing or removing jumpers Do not touch any object that could provide a current path to the com mon side of the circuit under test or power line earth ground Always make measurements with dry hands while standing on a dry insulated surface capable of withstanding the voltage being measured The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equip ment may be impaired Do not exceed the maximum signal levels of the instruments and ac cessories as defined in the specifications and operating informa tion and as shown on the instrument or test fixture panels or switching card When fuses are used in a product replace with same type and rating for continued protection against fir
70. cs adapter have the following boards and applications installed in my system data bus am encountering the following problem s and have received the following error messages codes have run the board diagnostics with the following results You can reproduce the problem by performing these steps 1 A Flowcharts for Substeps 171 Appendix A Set Subsystem Parameters Specify the channel type single ended 0 or ChannelType Property differential 1 Specify single ended if you are using pseudo differential channels x y Specify the resolution usually for DIN or DOUT Resolution Property Yv For A D and D A subsystems specify the data Encoding Property encoding type binary 0 or twos complement 1 Vv For A D and D A subsystems specify the voltage Range Property range for the subsystem FilterList Property Specify the filter for each A D channel Note Depending on your board some of these settings may not be programmable Refer to your device driver documentation for details 172 Flowcharts for Substeps Set Up Channel List and Channel Parameters Specify the size of the channel list gain list C ListSize Property channel inhibit list and synchronous digital 1 0 list y ChannelList Property Set up the channel list for the subsystem Speci
71. ded that you allocate a minimum of three buffers for analog output operations you can allocate one or more buffers The size of the buffers should be at least as large as the sampling or output rate for example if you are using a sampling rate of 100 ksamples s 100 kHz specify a buffer size of 100 000 samples Once you have allocated the buffers and for output operations filled them with data and set the valid number of samples put the buffers on the ready queue using the Queue property For example assume that you are performing an analog input operation that you allocated three buffers and that you put these buffers on the ready queue The queues appear on the ready queue as shown in Figure 27 Ready Queue Buffer 1 Buffer 2 Buffer 3 Inprocess Queue Done Queue Figure 27 Example of the Ready Queue 129 Chapter 5 130 Inprocess Queue When you start a continuous post trigger pre trigger or about trigger operation the data acquisition board takes the first available buffer from the ready queue and places it on the inprocess queue The inprocess queue holds the buffer that the specified data acquisition board is currently filling for input operations or outputting for output operations The buffer is filled or emptied at the specified clock rate Continuing with the previous example when you start the analog input operation the driver takes
72. delay approximately equal to the measurement period to allow the one shot to finish events are counted only during the active period of the one shot pulse 6 For the event counting C T subsystem read the number of events counted with the CTReadEvents method 7 Determine the measurement period using the following equation Measurement 1 Active Pulse Width of Period Actual Clock Frequency One Shot C T of One Shot C T 8 Determine the frequency of the clock input signal using the following equation Frequency Measurement _Number of Events Measurement Period 143 Chapter 5 144 Rate Generation Use rate generation mode to generate a continuous pulse output signal from the counter this mode is sometimes referred to as continuous pulse output or pulse train output You can use this pulse output signal as an external clock to pace analog input analog output or other counter timer operations To determine if the subsystem supports rate generation use the GetSSCaps method specifying the capability OLSSC_SUP_CTMODE_RATE If this method returns a non zero value the capability is supported To specify a rate generation mode use the CTMode property specifying the generate rate parameter 1 Specify the C T clock source for the operation In rate generation mode either the internal or external C T clock input source is appropriate depending on your application refer to page 154 for information on specify
73. e Starting the example produces a screen similar to that shown in Figure 16 42 Using the DTx EZ Examples Eid DTx EZ Scope DTDEMO of x Channel 0 Enable Filter Gain Volts o 1 d Channel 1 O Enable Filter Gain Volts Channel 2 O Enable Filter Gain Volts HE E O Windowed J FFT H AutoScale Size Acquisition Window Type Frequency O Enable Filter Gain 1000 0 1 Rectanoular a Volts Horizontal Vertical Trigger Secs Div Position Volts Div Allo txema Invert Ch 1 a Aaa LNU AJ D Position Mode Di Secs Figure 16 Sample Scope Screen E 43 Chapter 2 2 Z Property Method Function and Subroutine Summary MitroducHon en seesi i hese ii Caa EE keep bedD 46 Data Acquisition Custom Control 0000 47 Data Management DLLs 0 00 64 DT Plot Custom Control sssaeusa asunar nnne runar 69 45 Chapter 3 Introduction This chapter summarizes the properties methods functions and subroutines provided by the Data Acquisition and the DT Plot Custom Controls in DTx EZ 46 Property Method Function and Subroutine Summary Data Acquisition Custom Control The Data Acquisition Custom Control provides the following categories of data acquisition tools Information properties and methods page 47 e Initialization properties page 57 e Configuration properties and functions
74. e board upon its installation SubSystem Property Provides the means for the software to associate specific requests with a particular subsystem on a board it must be called after the Board property and before any other tool SubSysElement Sets and returns the subsystem s element number May be Property used in conjunction with the SubSysType property as a replacement for the SubSystem property SubSysType Property Sets and returns the subsystem s type May be used in conjunction with the SubSysElement property as a replacement for the SubSystem property 57 Chapter 3 Confi guration Properties and Functions Once you have initialized a board and subsystem and determined what its capabilities are set or return the value of the subsystem s parameters using the configuration properties and functions listed in Table 7 Note that italic text indicates a the name of an alternate function call Table 7 Configuration Properties and Functions Feature Properties and Functions Description Data Flow DataFlow Property Sets and returns the data flow Mode mode Buffer Wrap WrapMode Property Sets and returns the buffer Mode processing wrap mode DMA DmauUsage Property Sets and returns the number of DMA channels to be used Triggered TriggeredScan Property Enables or disables triggered Scans scan mode MultiscanCount Property Sets and returns the number of times to scan p
75. e frequency is the number events divided by a specified duration To determine if the subsystem supports event counting and therefore frequency measurement use the GetSSCaps method specifying the capability OLSSC_SUP_CTMODE_COUNT If this method returns a non zero value the capability is supported You can perform a frequency measurement operation in one of two ways using the Windows timer to specify the duration this page or using a pulse of a known duration as the gate input signal to a counter timer configured for event counting mode page 142 The following subsections describe these ways of measuring frequency Using the Windows Timer To perform a frequency measurement operation on a single C T subsystem using the Windows timer to specify the duration perform the following steps 1 Use the CTMode property specifying the count events 0 parameter 2 Specify the input clock source using the ClockSource property In frequency measurement mode an external C T clock source is more useful than the internal C T clock source refer to page 154 for more information on the external C T clock source 3 Use the GateType property specifying the no gate type parameter 0 to set the gate type to software 4 Use the MeasureFrequency method to specify the duration of the Windows timer which has a resolution of 1 ms and to start the frequency measurement operation 140 Software Architecture Frequency is determined
76. e hazard Chassis connections must only be used as shield connections for measuring circuits NOT as safety earth ground connections If you are using a test fixture keep the lid closed while power is ap plied to the device under test Safe operation requires the use of a lid interlock 5 03 Ifa screw is present connect it to safety earth ground using the wire recommended in the user documentation The A symbol on an instrument indicates that the user should re fer to the operating instructions located in the manual The A symbol on an instrument shows that it can source or mea sure 1000 volts or more including the combined effect of normal and common mode voltages Use standard safety precautions to avoid personal contact with these voltages The Ai symbol indicates a connection terminal to the equipment frame The WARNING heading in a manual explains dangers that might result in personal injury or death Always read the associated infor mation very carefully before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the warranty Instrumentation and accessories shall not be connected to humans Before performing any maintenance disconnect the line cord and all test cables To maintain protection from electric shock and fire replacement components in mains circuits including the power transformer test leads and input
77. e number of times to scan the channel gain q MultiscanCount Property 3 list per trigger retrigger 175 Appendix A Set Up Input Buffering In this flowchart a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name C WrapMode Property AllocBuffer Function olDmAllocBuffer or CallocBuffer Function olDmCallocBuffer Vv Queue Property Allocate more buffers Specify the buffer wrapping mode if none 0 buffers are not reused if no buffers are found on the ready queue if multiple 1 completed buffers are taken from the done queue and continuously reused when no buffers are found on the ready queue if single 2 a single buffer is continuously reused Use the AllocBuffer function o DmAllocBuffer to allocate a buffer of samples where each sample is 2 bytes use the CallocBuffer function o DmCallocBuffer to allocate a buffer of samples of a specified size Put the buffer onto the ready queue A minimum of three buffers is recommended for continuous input operations if you are not using single wrap mode e USA Equipment L NET 176 An Interworld Highway LLC Company Flowcharts for Substeps Set Up Output Buffering In this flowchart a function or subroutine name
78. e operation manually Once you have set up the parameters for a single value operation use the GetSingleValue method to acquire a single analog or digital 112 Software Architecture value use the PutSingleValue method to output a single analog or digital value Continuous Operations For a continuous operation you can specify any supported subsystem capability including a channel gain list clock source trigger source pre trigger source retrigger source DMA channel and buffer Call the Start method to start a continuous operation To stop a continuous operation perform either an orderly stop using the Stop method or an abrupt stop using the Abort or Reset method In an orderly stop Stop method the board finishes acquiring the specified number of samples stops all subsequent acquisition and transfers the acquired data to a buffer on the done queue all subsequent triggers or retriggers are ignored In an abrupt stop Abort method the board stops acquiring samples immediately the acquired data is transferred to a buffer and put on the done queue however the buffer may not be completely filled All subsequent triggers or retriggers are ignored The Reset method reinitializes the subsystem after stopping it abruptly Refer to page 128 for more information on buffers and queues Note For analog output operations you can also stop the operation by not sending new data to the board The operation stops
79. eady queue 128 RealFFT subroutine 68 ReAllocBuffer subroutine 67 ReCallocBuffer subroutine 67 redraw 167 related documents xv ReleaseSimultaneousStartList subroutine 63 98 165 repaint 167 repetitive one shot operation 151 support for 55 151 requirements 8 reset a simultaneous operation 165 an operation 184 Reset method 61 184 in continuous operations 113 in event counting operations 139 in rate generation operations 145 in repetitive one shot operations 152 in simultaneous operations 165 resolution 100 actual available during runtime 100 bits of supported 100 quantity available during runtime 100 quantity of 54 100 software programmable support 54 100 specify number of bits 100 Resolution property 60 100 in setting parameters 172 Resolutions Values property 76 Resolution Values property 49 100 retrigger extra mode 121 internal mode 120 maximum scans per 52 119 setting the frequency for 121 ReTrigger property 60 125 in retrigger extra mode 122 in triggered scan mode 175 retrigger scan support for extra triggered scan mode 52 121 retriggered scan support for internal mode 52 120 RetriggerFreq property 58 in internal retrigger mode 120 in retrigger extra mode 122 in triggered scan mode 175 RetriggerMode property 58 in internal retrigger mode 120 in retrigger extra mode 121 Index in scan per trigger mode 119 in triggered scan mode 175 S sampling theory 123 scale automatically for plots 167 setti
80. eful than the internal C T clock source refer to page 154 for more information on specifying the C T clock source Also specify the gate type that enables the operation refer to page 157 for more information on specifying the gate type Start an event counting operation using the Start method To read the current number events counted use the CTReadEvents method 138 Software Architecture To stop the event counting operation call the Stop Abort or Reset method Reset stops the operation and reinitializes the subsystem after stopping it Some subsystems also allow you to pause the operation using the Pause method and then resume the paused operation using the Continue method To determine if pausing is supported use the GetSSCaps method specifying the OLSSC_SUP_PAUSE capability If this method returns a non zero value the capability is supported Figure 33 shows an example of an event counting operation In this example the gate type is low level high level disables operation Gate Input low level Signal enables operation External C T Clock lt p Input Signal 3 events are counted while the operation is enabled event counting event counting operation starts operation stops Figure 33 Example of Event Counting 139 Chapter 5 Frequency Measurement You can also use event counting mode to measure the frequency of the clock input signal for the counter sinc
81. em use the GetSSCaps method specifying the capability OLSSC_NUMRESOLUTION To list the actual bits of resolution supported use the EnumSSCaps function specifying the OL_ENUM_RESOLUTION capability During runtime use the numResolutions property to list the number of resolutions available to the subsystem use the Resolution Values property to list the actual resolutions available to the subsystem Use the Resolution property to specify the number of bits of resolution to use for the subsystem Channels Each subsystem or element of a subsystem type can have multiple channels To determine how many channels the subsystem supports use the GetSSCaps method specifying the OLSSC_NUMCHANNELS capability 100 Software Architecture Specifying the Channel Type DTx EZ supports the following channel types e Single ended Use this configuration when you want to measure high level signals noise is insignificant the source of the input is close to the device and all the input signals are referred to the same common ground To determine if the subsystem supports the single ended channel type use the GetSSCaps method specifying the OLSSC_SUP_SINGLEENDED capability If this method returns a non zero value the capability is supported To determine how many single ended channels are supported by the subsystem use the GetSSCaps method specifying the OLSSC_MAXSECHANS capability e Differential Use this configuration when you
82. ent counting operations 84 in frequency measurement operations 143 custom control adding to Visual Basic 10 adding to Visual C 11 Data Acquisition Custom Control 3 DT Plotting Custom Control 3 cut off frequency list 111 D DAC Waveform Generator example 25 Data Acquisition Custom Control 3 adding to Visual Basic 10 adding to Visual C 11 data encoding 99 DataFlow property 58 in continuous post trigger operations 114 in continuous about trigger operations 117 in continuous buffered input operations 79 in continuous buffered output operations 81 in continuous pre trigger operations 115 in single value operations 77 112 Index DataType property 70 166 in setting plot re operation parameters 186 DDE Server and Client example 37 DeviceName property 48 differential channel type 101 differential input quantity of channels for 54 101 support for 54 101 digital event trigger 127 support for 55 127 digital I O example of 35 DIOList property 59 106 in setting channel parameters 173 divider maximum supported 156 minimum supported 156 DMA 135 quantity of channels supported 51 136 support for gap free continuous operation with dual 51 136 support for gap free continuous operation with no 51 136 support for gap free continuous operation with single 51 136 DmaUsage property 58 136 in continuous buffered input operations 79 in continuous buffered output operations 81 done queue 131 removing buffers
83. er timer mode as one shot and wire the signals appropriately Figure 38 shows an example of a one shot operation using an external gate input rising edge a clock output frequency of 1 kHz one pulse every 1 ms a low to high pulse type and a duty cycle of 99 99 Figure 39 shows the same example using a duty cycle of less than or equal to 1 149 Chapter 5 One Shot Operation Starts External Gate Signal Clock 1 ms period 99 99 duty cycle Pulse Output Signal Figure 38 Example of One Shot Mode Using a 99 99 Duty Cycle 150 Software Architecture One Shot Operation Starts External Gate Signal Clock 1 ms period lt q p a Pulse Output lt 1 duty cycle Signal 7 Figure 39 Example of One Shot Mode Using a Duty Cycle Less Than or Equal to 1 Repetitive One Shot Use repetitive one shot mode to generate a pulse output signal each time the board detects a trigger determined by the gate input signal You can use this mode to clean up a poor clock input signal by changing its pulse width then outputting it To determine if the subsystem supports repetitive one shot mode use the GetSSCaps method specifying the capability OLSSC_SUP_CTMODE_ONESHOT_RPT If this method returns a non zero value the capability is supported To specify a repetitive one shot operation use the CTMode property specifying the re
84. er trigger retrigger RetriggerMode Property Sets and returns the retrigger mode RetriggerFreq Property Sets and returns the frequency of the internal retrigger when using internal retrigger mode TEquipment 58 A NET n Interworld Highway LLC Company Property Method Function and Subroutine Summary Table 7 Configuration Properties and Functions cont Feature Properties and Functions Description Channel ListSize Property Sets and returns the size of the Gain List channel gain list ChannelList Property Sets and returns the channel number of a channel gain list entry GainList Property Sets a gain value for a channel gain list entry InhibitList Property Enables disables channel entry inhibition for a channel gain list entry DIOList Property Sets and returns the digital value to output for the channel gain list entry Synchronous SyncDIOUsage Property Enables disables synchronous Digital I O digital I O operations Channel ChannelType Property Sets and returns the channel Type configuration type of a channel Filters FilterList Property Sets and returns the analog filter that may be applied to each input or output channel Ranges Range Property Sets and returns the voltage range for a subsystem Get Channel Range Function olDaGetChannelRange Gets the voltage range for a channel MaxRange Property Returns the maximum voltage value
85. er Parameters MarkerH10n and Display the horizontal MarkerH1On and vertical MarkerV1On Property MarkerV1On marker lines MarkerH2On and Display the second horizontal MarkerH2On and MarkerV2On Property vertical MarkerV2On marker lines t Set the position of the active markers with MarkerH1Pos MarkerH1Pos for the first horizontal marker MarkerH2Pos and MarkerH2Pos for the second horizontal marker MarkerV1Pos MarkerV1Pos for the first vertical marker and MarkerV2Pos Property MarkerV2Pos for the second vertical marker MarkerColor Property Change the marker lines color If you wish to alter the MarkerH1Data value of the data point ata Modify NS MarkerH2Data and marker enter the desired marker data MarkerV1Data value into the appropriate property Use MarkerH1Data for the point at the first horizontal marker MarkerH2Data for the point at the second horizontal marker MarkerV1 Data for the point at the first horizontal marker and MarkerV2Data for the point at the second horizontal marker The plot must have buffer data to use these properties MarkerV2Data Property point 106 An Interworld Highway LLC Company A A D burst example 20 continuous example 29 abort a simultaneous operation 165 an operation 184 Abort method 61 184 in continuous operations 113 in event counting operations 139 in rate generation operations 145 in repetitive one
86. erated when an analog event occurs To determine if the subsystem supports an analog event trigger use the GetSSCaps method specifying the capability OLSSC_SUP_ANALOGEVENTTRIG If this method returns a non zero value the capability is supported Digital Event Trigger Source For this trigger source a trigger is generated when a digital event occurs To determine if the subsystem supports a digital event trigger use the GetSSCaps method specifying the capability OLSSC_SUP_DIGITALEVENTTRIG If this method returns a non zero value the capability is supported Timer Event Trigger Source For this trigger source a trigger is generated when a counter timer event occurs To determine if the subsystem supports a timer event trigger use the GetSSCaps method specifying the capability OLSSC_SUP_TIMEREVENTTRIG If this method returns a non zero value the capability is supported Extra Trigger Source Extra trigger sources may be defined by your device driver To determine how many extra triggers are supported by the subsystem use the GetSSCaps method specifying the capability OLSSC_NUMEXTRATRIGGERS Refer to your board driver documentation for a description of these triggers The extra trigger sources may be internal or external Refer to the previous sections for information on how to specify internal and external triggers 127 Chapter 5 128 Buffers The buffering capability usually applies to A D and D A subsystems
87. erations The flowchart in Figure 21 provides an overview of the steps required to perform a frequency measurement operation Many steps represent several substeps if you are unfamiliar with the functions required to perform a step refer to the indicated page in Appendix A for more information Optional steps appear in shaded boxes Note If you need more accuracy than the Windows timer provides refer to page 140 Select the board with the Board property Select a C T subsystem with the SubSystem property or use the SubSysType and SubSysElement properties Vv Set the cascade mode using the CascadeMode property Vv Set up the clocks see page 183 y Specify the count events counter timer mode by setting the CTMode property to 0 y Go to the next page J Figure 21 Performing a Frequency Measurement Operation 85 Chapter 4 C Continued from previous page Configure the subsystem using the Config method Start the frequency measurement operation using the MeasureFrequency method Yes Get the Use the LongtoFreq lParam macro to get the measured frequency value float Freq Freq LongtoFreq lParam MeasureDone event Figure 21 Performing a Frequency Measurement Operation cont 86 Programming Flowcharts Pulse Output Operations The flowchart in Figure
88. ery and specify refer to the following e For analog and digital I O operations refer to page 99 e For the counter timer operations refer to page 137 and e For simultaneous operations refer to page 164 Once you have set up the parameters appropriately for the operation you want to perform use the Config method to configure the parameters before performing the operation 95 Chapter 5 96 Handling Events The data acquisition board notifies your application of buffer movement and other activities by generating events Refer to DTx EZ online help for more information on the events that can be generated Handling E DTx EZ Custom Controls produce two types of errors The first is an OLE automation error that occurs when accessing one of the control s properties or methods The second type of error occurs during the rrors actual operation of the control s subsystem and is signaled by the OverrunError Event UnderrunError Event TriggerError event or EventError Event Resolve the second error type by entering code in your control s event handler subroutine Resolve an OLE automation error with one of the following routines depending on your development environment From Visual Basic On if Error GoTo DTAcg321 Start start the subsystem Exit Sub DealWithIt Err Number OL MsgBox DTAcq321 Produced DT Open Layers ni DealWithIt 440 then E automat
89. ew selection If your board provides software configurable input mode selection you do not need to change any jumper settings Clock Source and Trigger Source You can select either an internal or an external clock source and trigger source Clock frequency sources and triggers help you synchronize data conversions with off board events External frequency sources can also be used to produce clock frequencies that cannot be achieved with the board s onboard oscillator Range allows you to select the input voltage range Ranges can be unipolar or bipolar Encoding lets you choose the input data encoding format 23 Chapter 2 24 Note Because older boards use an onboard jumper to set the input voltage range and data encoding format these settings cannot be changed until you remove the board and change the jumper configuration to correspond with the new selections If your board provides software configurable settings you do not need to change any jumper settings Triggered Scan You can enable this mode on boards that support this feature Refer to your board s driver documentation to determine if it is supported on your board Triggered scan mode performs scans through the channel gain list where each scan is initiated by the onboard trigger On some boards the interval between the scans is programmable Select the desired options and click OK When you have completed the conf
90. from 133 DT Plotting Custom Control 3 adding to Visual Basic 10 adding to Visual C 11 DT Open Layers 2 DTx EZ 2 duty cycle 162 in one shot operations 149 E element defined 94 list names and types 95 list quantity of 95 selecting 94 encoding 99 binary support 54 99 twos complement support 54 99 Encoding property 60 100 example using 23 in setting parameters 172 EnumBoards method 48 EnumSS method 48 76 95 EnumSSCaps method 49 76 error checking 76 event 96 defined 5 respond to 178 event counting operation 138 performing 83 support for 55 138 example A D burst 20 About Trigger 33 Chartlt 41 Continuous A D 29 Continuous FFT 40 DAC Waveform Generator 25 DDE Server and Client 37 Digital 1 O 35 199 Index 200 Scope 42 Single Value 31 external analog threshold negative trigger 126 support for 54 126 external analog threshold positive trigger 126 support for 54 126 external clock 123 155 support for 55 123 155 external digital TTL trigger 125 support for 54 125 extra clock 124 157 quantity of 55 124 157 extra trigger 127 quantity supported 55 127 F Fast Fourier Transform example of 40 FFT example 40 FIFO present in data path 57 filter 111 list available during runtime 111 list cut off frequency 111 per channel support 54 111 quantity available during runtime 111 quantity of selections 54 111 FilterList property 59 111 in setting parameters 172 FilterValues property 4
91. fy the gain for each channel in the channel list AA the gain list parallels the channel list Use a gain GainList Property of 1 for channels that do not support programmable gain Enable disable inhibition for the specified channel Vv entries If inhibited the acquired values from the InhibitList Property specified entries are discarded Vv Enable disable a synchronous digital output SyncDIOUsage Property operation 3 P For subsystems that support synchronous digital I O specify the values to output to the dynamic DIOList Property digital output channels as each entry in the channel list is sampled 173 Appendix A Set Clocks Triggers and Pre Triggers Using an Specify internal 0 internal the default to select the internal clock or ClockSource Property clock No one of the hardware specific clocks extra N to select an extra available internal clock v Specify the frequency of the Frequency Property internal clock The y ClockSource Property Vv ClockDivider Property driver sets the actual frequency as closely as possible to the number specified Specify external 1 to select the external clock or one of the hardware specific clocks extra N to select an extra available external clock Specify a clock divider to apply to the external clock source The driver
92. g a channel list described in the next section Specifying One or More Channels You acquire data from or output data to one or more channels using a channel list DTx EZ provides features that allow you to group the channels in the list sequentially either starting with 0 or with any other analog input channel or randomly In addition DTx EZ allows you to specify a single channel or the same channel more than once in the list Your device however may limit the order in which you can enter channel in the channel list Software Architecture To determine how the channels can be ordered in the channel list for your subsystem use the GetSSCaps method specifying the OLSSC_RANDOM_CGL capability If this method returns a non zero value the capability is supported you can order the channels in the channel list in any order starting with any channel If this capability is not supported use the GetSSCaps method specifying the OLSSC_SUP_SEQUENTIAL_CGL capability If this method returns a non zero value the capability is supported you must order the channels in the channel list in sequential order starting with any channel If this capability is not supported use the GetSSCaps method specifying the OLSSC_SUP_ZEROSEQUENTIAL_CGL capability If this method returns a non zero value the capability is supported you must order the channels in the channel list in sequential order starting with channel 0 To determine if the subsystem s
93. h Method Transfers all data buffers held by Operations the subsystem to the done queue Queue Property Adds buffers to the ready queue and retrieves buffers from the done queue QueueSize Property Gets the size of the specified queue ready done or inprocess for a specified subsystem The size indicates the number of buffers on the specified queue Counter Timer Operations CTReadEvents Method Gets the number of events that have been counted since the subsystem was started with the Start method MeasureFrequency Method Measures the frequency of the input clock source for the selected counter timer Power Operations PowerOn Method Powers on a USB module and restores the configuration of the module at the time that it was last powered down PowerOff Method Stores the configuration of the USB module and powers down the module Errors ClearError Method Clears the LastErrNum property LastErrNum Property Retrieves the last known DT Open Layers error generated by the DTAcq32 Control LastErrDescription Property Retrieves a string representation of the last known DT Open Layers error generated by the DTAcq32 Control 62 Property Method Function and Subroutine Summary Table 8 Operation Properties Methods Functions and Subroutines cont Properties Methods Operation Functions and Subroutines Description Simult
94. h time it gets a BufferDone event your application program should remove the buffers from the done queue using the Queue property Your application program can then process the data in the buffer For an input operation you can copy the data from the buffer to an array in your application program using the CopyFromBuffer olDmGetBufferPtr subroutine For continuously paced analog output operations you can fill the buffer with new output data using the CopyToBuffer o DmGetBufferPtr subroutine When you are finished processing the data you can put the buffer back on the ready queue using the Queue property if you want your operation to continue For example assume that you processed the data from Buffer 1 and put it back on the ready queue The queues would appear as shown in Figure 31 Ready Queue Buffer 3 Buffer 1 Inprocess Queue Buffer 2 Done Queue Figure 31 Putting Buffers Back on the Ready Queue 133 Chapter 5 134 When the data acquisition operation is finished use the Flush method to transfer any data buffers left on the subsystem s ready queue to the done queue Once you have processed the data in the buffers free the buffers from the memory using the FreeBuffer oJ DmFreeBuffer subroutine Buffer Wrap Modes Most Keithley data acquisition boards can provide gap free data meaning no samples are missed when data is acquired or output You ca
95. he capability is supported Specify the retrigger mode as OL_RETRIGGER_EXTRA using the RetriggerMode property 121 Chapter 5 122 Use the ReTrigger property to specify the retrigger source Refer to page 124 and to your board device driver documentation for supported triggering sources The conversion rate of each channel in the scan is determined by the frequency of the A D sample clock refer to page 122 for more information on clock sources The conversion rate of each scan is determined by the period between retriggers For external retriggers the period between retriggers cannot be accurately controlled For internal retriggers specify the period between retriggers using the RetriggerFreq property see page 120 The board ignores triggers that occur while it is acquiring data Only retrigger events that occur when the board is waiting for a trigger are detected and acted on Some boards may generate a TriggerError event Clock Sources DTx EZ defines internal this page external page 123 and extra page 124 clock sources described in the following subsections Note that you cannot specify a clock source for single value operations Internal Clock Source The internal clock is the clock source on the board that paces data acquisition or output for each entry in the channel gain list To determine if the subsystem supports an internal clock use the GetSSCaps method specifying the OLSSC_SUP_INTCLOCK capability
96. hod specifying the OLSSCE_MAXCLOCKDIVIDER capability To determine the minimum clock divider that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MINCLOCKDIVIDER capability Internally Cascaded Clock You can also internally connect or cascade the clock output signal from one counter timer to the clock input signal of the next counter timer in software In this way you can create a 32 bit counter out of two 16 bit counters To determine if the subsystem supports internal cascading use the GetSSCaps method specifying the OLSSC_SUP_CASCADING capability If this method returns a non zero value the capability is supported Specify whether the subsystem is internally cascaded or not single using the CascadeMode property Note Ifa counter timer is cascaded you specify the clock input and gate input for the first counter in the cascaded pair For example if counters 1 and 2 are cascaded specify the clock input and gate input for counter 1 However use the output from counter 2 Software Architecture Extra C T Clock Source Extra C T clock sources may be defined by your device driver To determine how many extra clock sources are supported by your subsystem use the GetSSCaps method specifying the OLSSC_NUMEXTRACLOCKS capability Refer to your board driver documentation for a description of these clocks To specify internal or external extra clock sources and their frequencies and or clock div
97. hysical buffer size in bytes GetDataBits Function olDmGetDataBits Gets the number of valid data bits GetDataWidth Function olDmGetDataWidth Gets the width of each data sample GetErrorString Function olDaGetErrorString olDmGetErrorString olDspGetErrorString Gets the string corresponding to a data management error code value GetMaxSamples Function olDmGetMaxSamples Gets the physical size of the buffer in samples GetTimeDateStamp Function olDmGetTimeDateStamp Gets the time and date of the buffer s data SetValidSamples Function olDmSetValidSamples Sets the number of valid samples in the buffer Property Method Function and Subroutine Summary Table 9 Buffer Management Functions and Subroutines cont Functions and Subroutines Description GetValidSamples Function Gets the number of valid samples olDmGetValidSamples ReallocBuffer Subroutine Reallocates a buffer object alloc interface olDmReAllocBuffer ReCallocBuffer Subroutine Reallocates a buffer object calloc interface olDmReCallocBuffer Conversion Functions and Subroutines The data conversion utilities that are available in DTx EZ are listed in Table 10 Note The conversion utilities listed in Table 10 are intended for use by both application and system programmers Because of the differences in the two compliers the Visual Basic and Visual C libraries exist
98. iders refer to the previous subsections Gate Types The active edge or level of the gate input to the counter enables or triggers counter timer operations DTx EZ defines the following gate input types e Software page 158 5 e High Level page 158 e Low Level page 158 e High Edge page 159 e Low Edge page 159 e Any level page 159 e High Level debounced page 160 e Low Level debounced page 160 e High Edge debounced page 160 e Low Edge debounced page 161 and e Any level debounced page 161 To specify the gate type use the GateType property The following subsections describe these gate types 157 Chapter 5 Software Gate Type A software gate type enables any specified counter timer operation immediately when the GateType property is executed To determine if the subsystem supports a software gate use the GetSSCaps method specifying the OLSSC_SUP_GATE_NONE capability If this method returns a non zero value the capability is supported High Level Gate Type A high level external gate type enables a counter timer operation when the external gate signal is high and disables a counter timer operation when the external gate signal is low Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a high level external gate input use the GetS
99. if the subsystem supports an internal C T clock use the GetSSCaps method specifying the OLSSC_SUP_INTCLOCK capability If this method returns a non zero value the capability is supported To specify the clock source use the ClockSource property Using the Frequency property specify the frequency of the clock output signal To determine the maximum frequency that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MAXTHROUGHPUT capability To determine the minimum frequency that the subsystem can produce use the GetSSCapsEx method specifying the OLSSCE_MINTHROUGHPUT capability External C T Clock The external C T clock is a clock source attached to the board that paces counter timer operations for a C T subsystem The external C T clock is useful when you want to produce at rates not available with the internal clock or if you want to produce rates at uneven intervals To determine if the subsystem supports an external C T clock use the GetSSCaps method specifying the OLSSC_SUP_EXTCLOCK capability If this method returns a non zero value the capability is supported 155 Chapter 5 156 Specify the clock source using the ClockSource property Specify the clock divider using the ClockDivider property the clock input signal divided by the clock divider determines the frequency of the clock output signal To determine the maximum clock divider that the subsystem supports use the GetSSCapsEx met
100. iguration select Start to begin acquiring data Note that the menu name changes to Stop until the operation is done You can choose Stop to halt the operation at any time When the acquisition is complete a message indicates that a buffer of data was collected and where the file was created Using the DTx EZ Examples DAC Waveform Generator Example The DAC digital to analog converter waveform generator example dacwave vbp or dacwave mdp uses the D A subsystem to continuously output a sine wave square wave or triangle wave You can specify waveform frequency and the board on which to output the signal You could use this example to supply a test signal for circuit evaluation or a stimulus to your experiment When you run the example the Select Board dialog box appears Choose the desired board from the list and click OK The DAC Waveform Generator screen shown in Figure 4 appears Ei DTx EZ Dac Waveform generation DT2831 olx Configure Start WiewOutput DAC Buffers Done Figure 4 DAC Waveform Generator Screen 25 Chapter 2 Follow these steps 1 Select Configure gt Board to choose a data acquisition board from the list 2 Select Configure gt Output to configure the analog output settings for your board The Output Options dialog box shown in Figure 5 appears Refer to the A D Burst example in the previous section for information on these settings Interface Mode Range EOM
101. ils Figure 40 shows an example of a repetitive one shot operation using an external gate rising edge a clock output frequency of 1 kHz one pulse every 1 ms a low to high pulse type and a duty cycle of 99 99 Software Architecture Repetitive One Shot Operation Starts External Gate Signal Pulse Output Signal Clock Clock A 1 ms period a 1 ms period gt gt 99 99 duty cycle 99 99 duty cycle 99 99 duty cycle Figure 40 Example of Repetitive One Shot Mode Using a 99 99 Duty Cycle Figure 41 shows the same example using a duty cycle of 50 153 Chapter 5 Repetitive One Shot Operation Starts External Gate Signal Pulse Output Signal Figure 41 Example of Repetitive One Shot Mode Using a 50 Duty Cycle Clock 1 ms period gt 50 duty cycle Clock 1 ms period gt C T Clock Sources 154 e Internal C T clock this page e External C T clock page 155 50 duty cycle DTx EZ defines the following clock sources for counter timers e Internally cascaded clock page 156 and e Extra C T clocks page 157 The following subsections describe these clock sources Software Architecture Internal C T Clock The internal C T clock is the clock source on the board that paces a counter timer operation for a C T subsystem To determine
102. indicating that the first post trigger sample was acquired this sample is ignored 115 Chapter 5 116 Use the PreTrigger property to specify the trigger source that starts the pre trigger operation generally this is a software trigger Specify the post trigger source that stops the operation using the Trigger property Refer to page 124 and to your board driver documentation for supported sources Figure 25 illustrates continuous pre trigger mode using a channel list of three entries channel 0 channel 1 and channel 2 In this example pre trigger analog input data is acquired on each clock pulse of the A D sample clock refer to page 122 for more information on clock sources The board wraps to the beginning of the channel list and the acquisition repeats continuously until the post trigger event occurs As your buffers are filled and placed on the done queue PreTriggerBufferDone events occur When the post trigger action occurs acquisition stops and a QueueStopped event occurs ChanO Chan2 ChanO Chan2 ChanO A D Chan 1 I Chan 1 Sample Clock Pre trigger data acquired Acquisition stops Pre trigger event occurs Post trigger event occurs Figure 25 Continuous Pre Trigger Mode Continuous About Trigger Mode Use continuous about trigger mode when you want to acquire data both before and after a specific external event occurs This operation is equivalent to doing both
103. ine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C appears in italics following the Visual Get BufferReused Ye You may want to increment a counter E event Basic name Get Yes e Report that the The queue related events are queue relat gt operation has stopped QueueDone and QueueStopped ed event The buffer done events are BufferDone and PreTrigBufferDone Retrieve the buffer from the done queue Yes Get buffer done event Process data p Queue Property Yes Determine the GetValidSamples number of Function samples in the olDaGetValidSamples buffer Go to the next page Go to the next page 3 Flowcharts for Substeps Deal with Events and Buffers for Input Operations cont Continued from previous page Continued from previous page Copy all the veS Using samples in the CopyFromBuffer Visual buffer to a Visual Subroutine Basic Basic array No v Get a pointer olDmGetBufferPtr tO the buffer gt v Process the data buffer in your program a Recycle the Queue Property buffer if you want the v subsystem to fill it again when using no buffer or multiple buffer wrap See page 180 if you want
104. ing a Board To perform any data acquisition operation your application program ay must initialize the device driver for a specified board using the Board property At run time you can use the BoardList property This property lists the DT Open Layers boards available in your system Use the numBoards property to determine the number of DT Open Layers boards currently installed in your system Once you have selected a board you can specify a subsystem as described in the next section 93 Chapter 5 Specifying a Subsystem A subsystem refers to the major circuitry on a board DTx EZ defines the following subsystems e Analog input A D subsystem e Analog output D A subsystem e Digital input DIN subsystem e Digital output DOUT subsystem e Counter timer C T subsystem and e Serial port SRL subsystem Note The SRL subsystem is provided for future use It is not currently used by any DT Open Layers compatible data acquisition device A board can have multiple elements of the same subsystem type Each of these elements is a subsystem of its own and is identified by a subsystem type and element number Element numbering is zero based that is the first instance of the subsystem is called element 0 the second instance of the subsystem is called element 1 and so on For example if two digital I O ports are on your board two DIN or DOUT subsystems are available differentiated as element 0 and element 1 Once
105. ing the C T clock source Specify the frequency of the C T clock output signal For an internal C T the Frequency property determines the frequency of the output pulse For an external C T clock source the frequency of the clock input source divided by the clock divider specified with the ClockDivider property determines the frequency of the output pulse Specify the polarity of the output pulses high to low transitions or low to high transitions and the duty cycle of the output pulses refer to page 162 for more information Also specify the gate type that enables the operation refer to page 157 for more information on specifying the gate type Software Architecture Start rate generation mode using the Start method While rate generation mode is enabled the counter outputs a pulse of the specified type and frequency continuously As soon as the operation is disabled the pulse output operation stops To stop rate generation if it is in progress call the Stop Abort or Reset method Reset stops the operation and reinitializes the subsystem after stopping it Some subsystems also allow you to pause the operation using the Pause method and resume the paused operation using the Continue method To determine if pausing is supported use the GetSSCaps method specifying the OLSSC_SUP_PAUSE capability If this method returns a non zero value the capability is supported Figure 35 shows an example of an enabled rate generation o
106. inuous FFT Data Display as kaa 0 I Db A Ny 120 0 Frequency Hz 200 Figure 14 FFT Display Using the DTx EZ Examples Chartit Example This example chartit vbp or chartit mdp acquires data using the GetSingle Value method and plots the data using the plotting control s SinglePoint property in stripchart mode Click Start to begin sampling A timer control samples and plots each data point every 500 ms Click Stop to halt sampling A typical stripchart display is shown in Figure 15 Fi Strip Chart Example Bel Eg 10 Figure 15 Stripchart Display 41 Chapter 2 Scope Example This example generates and displays data from one to four analog input channels It includes typical oscilloscope functions such as single sweep or continuous scan horizontal and vertical offsets and adjustable time and amplitude settings The example also operates as a single channel spectrum analyzer with a number of popular windowing selections You may apply gains and filters if available and even invert Channel 2 data and add it to Channel 1 data Both manual and auto triggering as well as external triggering are possible By clicking the mouse on the plot display an exact voltage reading for each channel and the time of acquisition is displayed For further analysis you can apply various windowing formulas as well as FFTs to a single channel of data Both of these are performed at a user selected acquisition rat
107. ion error occurred error CStr DTAcq321 LastError End DTAcq321 LastErrl LE Description Software Architecture From Visual C try m_DTAcq321 Start start the subsystem catch COleDispatchException e char myError 100 sprintf myError DT Open Layers Error ld s e gt m_scError DTACQ32_ERRORBASE e gt m_strDescription AfxMessageBox myError e Delete delete what you have dealt with DTx EZ Visual Basic functions raise errors and you can deal with them in the following manner From Visual Basic On Error GoTo TrapIit ValidSamples ValidSamples hbuf Exit Sub TrapIit MsgBox Err Source Error CStr Err Number vbObjectError Err Description End Sub 97 Chapter 5 From Visual C ECODE ecode olDmGetValidSamples hbuf amp ulNumSamples if ecode OLNOERROR char msg 100 olDmGetErrorString ecode msg 100 AfxMessageBox msg Halting the Operation When you are finished performing data acquisition operations stop each subsystem with the Stop method Then release the simultaneous start list if used using the ReleaseSimultaneousStartList subroutine for Visual Basic or olDaReleaseSS List for Visual C 98 Software Architecture Analog and Digital I O Operations DTx EZ defines the follo
108. is dae geen kepy kesya 124 Software Internal Trigger Source 125 External Digital TTL Trigger Source 125 External Analog Threshold Positive Trigger Source 126 Contents External Analog Threshold Negative Trigger DOULCE indienne ae EEE TE tba oe need cap E S 126 Analog Event Trigger Source 0 000 0ee 127 Digital Event Trigger Source 00 127 Timer Event Trigger Source 00000 127 Extra Trigger Source neri 6 cece eee 127 BUES eriei ce oh tee ite det Rahn Redon odo Bates Beart 128 Ready Queue ekee tekee a ee e edie s 128 Done Queue 0 ccc cee een n eee 131 Buffer and Queue Management 133 Buffer Wrap Modes 606 c cece 134 DMA Resources erreiaren rnr eee eee 135 Counter Timer Operations 0 6 cece eee eee 137 Counter Timer Operation Mode 04 138 Event Counting 6 66 138 Frequency Measurement 0 eee ee eee 140 Using the Windows Timer 140 Using a Pulse of a Known Duration 142 Rate Generation 0 eee eee eee 144 ONE SKOT a cord senses ches tie Ske s ts Malach Senile enn tasted 148 Repetitive One Shot 0 66 c cece eee reks 151 C T Clock Sources 0 ccc eee eens 154 Internal C T Clock 1 0 0 0 0 0 c cee 155 External C T Clock 0 0 00 cece ce eee 155 Internally Cascaded Clock 000 156 Ext
109. it is modular and uses Windows DLLs DT Open Layers is easily expanded to support new more powerful hardware devices without re linking or rebuilding applications Therefore you do not need to rewrite your code when adding new data acquisition boards that have DT Open Layers compliant device drivers DT Open Layers protects your software investment now and in the future Provides Custom Controls The DTx EZ provides two custom controls e Data Acquisition Custom Control and e Plotting Custom Control The following subsections describe these controls Overview The Data Acquisition Custom Control The Data Acquisition Custom Control facilitates performing data acquisition functions Each copy of the Data Acquisition Custom Control operates on a single subsystem of the supported board at a time However Visual Basic and Visual C lets you use multiple copies of this control operating simultaneously controlling different subsystems on the same board or even on different boards DTx EZ determines the capabilities of each subsystem for your data acquisition board The board s supported capabilities are listed in the custom control s Properties window You can control the subsystem s operation by manipulating the subsystem s properties You can change the properties at design time in the Properties window or at run time using simple Visual Basic or Visual C code Each subsystem may have multiple channels For example the A
110. jacks must be purchased from Keithley Instru ments Standard fuses with applicable national safety approvals may be used if the rating and type are the same Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component Note that se lected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product If you are unsure about the applicability of a replacement component call a Keithley Instruments office for information To clean an instrument use a damp cloth or mild water based cleaner Clean the exterior of the instrument only Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument Products that consist of a circuit board with no case or chassis e g data acquisition board for installation into a com puter should never require cleaning if handled according to instruc tions If the board becomes contaminated and operation is affected the board should be returned to the factory for proper cleaning ser vicing Table of Contents About this Manual 0000 e eee eee xiii Intended Audience 00 cece cece eee eee ee xiii What You Should Learn from this Manual xiii Organization of this Manual 0008 xiv Conventions Used in this Manual 0005 xiv Related Information 0
111. k Start to begin the acquisition click Stop to end it Figure 10 shows a typical acquisition Fi DT Open Layers About trigger Example 5 x Marker Position 3333 Marker Data 7 470703 8 000488 1 999512 0 4333 Figure 10 About Trigger A D Display 33 Chapter 2 34 The y axis setting volts corresponds to the minimum and maximum voltage settings for the selected board The x axis setting number of samples is determined by the data buffer size and selected sampling frequency You can modify these properties within the example s form_load event subroutine Using the DTx EZ Examples Digital I O Example This example dio vbp or dio mdp demonstrates the use of a single value operation with DIN and DOUT subsystems You could use this example to interface with sensors and control devices that use digital signals After selecting the board the screen shown in Figure 11 appears olx Eid Digital 1 0 TREK 0T F4 Hex Digital Output TEKH FF Click lights to change Digital Output value Figure 11 Monitoring Digital I O Operations The light bulbs represent the digital input and output data A timer control reads the digital input data at regular intervals The light bulbs turn on and off to indicate the value read from the DIN subsystem You can change the digital output value by clicking the light bulbs in the bottom half of the display As you
112. lity is supported You can synchronize the triggers of subsystems by specifying the same trigger source for each of the subsystems that you want to start simultaneously and wiring them to the device if appropriate Use the GetSimultaneousStartList o DaGetSSList function to allocate a simultaneous start list Then use the PutSubSysOnSSList olDaPutDassToSSList subroutine to put the subsystems that you want to start simultaneously on the start list Pre start the subsystems using the SimultaneousPreStart olDaSimultaneousPreStart subroutine Pre starting a subsystem ensures a minimal delay once the subsystems are started Once you call the SimultaneousPreStart ol DaSimultaneousPreStart subroutine do not alter the settings of the subsystems on the simultaneous start list 164 Software Architecture Start the subsystems using the SimultaneousStart olDaSimultaneousStart subroutine When started both subsystems are triggered simultaneously Note Do not call the Start method when using simultaneous start lists since the subsystems are already started When you are finished with the operations call the ReleaseSimultaneousStartList ol DaReleaseSSList subroutine to free the simultaneous start list To stop the simultaneous operations call the Stop for an orderly stop Abort for an abrupt stop or Reset method for an abrupt stop that reinitializes the subsystem 165 Chapter 5 Plot Control Operatio
113. lock frequency with the Frequency property if using an internal clock source or the ClockDivider property if using an external clock source the gate type with the GateType property the type of output pulse with the PulseType property and the pulse width with the PulseWidth property The pulse width and period are used to determine the time that the gate is active c Configure this C T subsystem with the Config method 2 Set up another C T subsystem for event counting mode a Use the CTMode property specifying the count events parameter 0 to set up this C T subsystem for event counting mode and therefore a frequency measurement operation b For this C T subsystem use the ClockSource property to specify the clock source you wish to measure For frequency measurement operations an external C T clock source is more useful than the internal C T clock source refer to page 154 for more information on the external C T clock source 142 Software Architecture c For this C T subsystem use the GateType property to specify the gate type ensure that the gate type for this C T subsystem matches the active period of the output pulse from the C T subsystem configured for one shot mode d Configure this C T subsystem with the Config method 3 Start the counter timer configured for event counting mode with the Start method 4 Start the counter timer configured for one shot mode with the Start method 5 Allow a
114. lot that shows you what your plots will look like Whenever you change a property the plot immediately displays the effects of your changes For some properties you can enter new data for the plot at either design time or run time Provides Properties Methods and Events The Data Acquisition and DT Plot Custom Controls have unique properties methods and events described as follows e Properties represent the variables that allow you to configure the data acquisition or plotting operation Many read write properties are accessible in the Properties window at design time or at runtime Some read write properties are lists that may be accessed through the control s custom property pages Other properties are read only you can access them only at runtime These read only properties represent variables that you can use to determine data acquisition or plotting capabilities Overview Note Each Data Acquisition Custom Control can be associated with a single subsystem at a time This means that you must first select the board and subsystem you want to use before you can configure the subsystem s properties When a custom control is created its properties are set to the default settings You must modify the properties if you want to change their values from the default settings e Methods are tools that are used in the Visual Basic or Visual C code to provide runtime control of data acquisition operations no methods are
115. ls 2 6 0 Sample channel 6 and output a value of 0 to the dynamic digital output channels 3 4 0 Sample channel 4 and output a value of 0 to the dynamic digital output channels In this case when channel 7 is sampled a value of 1 is output to the dynamic digital output channels When channel 5 is sampled a value of 1 is output to the dynamic digital output channels When channels 6 and 4 are sampled a value of 0 is output to the dynamic digital output channels If your device had two dynamic digital output bits and a value of 1 is output 01 in binary format a value of 1 is written to dynamic digital output bit 0 and a value of 0 is written to dynamic digital output bit 1 Similarly if a value of 2 is output 10 in binary format a value of 0 is written to dynamic digital output bit 0 and a value of 1 is written to dynamic digital output bit 1 Note If you are controlling sample and hold devices with these channels you may need to program the first channel at the sample logic level and the following channels at the hold logic level see your board device driver documentation for details 107 Chapter 5 108 Ranges The range capability applies to A D and D A subsystems only Depending on your subsystem you can set the range for the entire subsystem or the range for each channel To determine if the subsystem supports the range per channel capability use the GetSSCaps method spe
116. ltiple board support 6 multiple buffer wrap mode 135 support for 51 135 MultiscanCount property 58 in internal retrigger mode 121 in scan per trigger mode 120 in triggered scan mode 119 175 203 Index 204 N negative analog threshold trigger support 54 126 numBoards property 48 76 93 numChannels property 70 166 in setting plot re operation parameters 186 numFilters property 49 76 111 numGains property 49 76 110 numRanges property 49 76 108 numResolutions property 49 76 100 numSubSystems property 48 95 Nyquist Theorem 123 O object oriented design 6 OL_ENUM_FILTERS 111 OL_ENUM_GAINS 109 OL_ENUM_RANGES 108 OL_ENUM_RESOLUTION 100 olDaFlushFromBufferInprocess in inprocess buffer transfer 180 with done queue 132 with inprocess queue 130 olDaGetChannelRange 59 olDaGetErrorString 66 olDaGetSSList 63 164 olDaGetValidSamples in buffer input operations 178 olDaGetValidSamples subroutine in buffer output operations 182 olDaPutDassToSS List 63 164 olDaReleaseSSList 63 98 165 olDaSetValidSamples in output buffering 177 olDaSimultaneousPreStart 63 164 olDaSimultaneousStart 63 165 olDmAllocBuffer 65 128 in inprocess buffer transfer 180 in input buffering 176 in output buffering 177 olDmCallocBuffer 65 128 in inprocess buffer transfer 180 in input buffering 176 in output buffering 177 olDmFreeBuffer 66 134 olDmGetBufferPtr 66 133 in buffer input operations 179 in buffer output o
117. ly scans channels 0 through 5 using a gain of 1 for channels 0 2 and a gain of 8 for channels 3 5 3 Select Configure gt Input to configure the analog input settings for your data acquisition board The Input Options dialog box shown in Figure 3 appears amp Input Options x Interface Mode Range LCR Single Ended Encoding Differential Offset Binary 2 s Complement ClockSource Internal Triggered Scan O Enable Retrigger Frequency External Clock Trigger Source Internal External Figure 3 Configure the Analog Input Settings 22 Using the DTx EZ Examples Any settings that are not software configurable for your board are inactive The available settings are as follows Interface Mode allows you to select either single ended or differential inputs Most data acquisition boards can be configured for either 16 single ended or 8 differential input channels Single ended inputs share a common ground Differential inputs use a separate ground for each channel which halves the channel capacity Differential inputs can improve accuracy where long cables low level input ranges lt 1 V full scale or high resolution converters gt 12 bits are used Note If your board uses an onboard jumper to set the input mode do not change this setting until you remove the board and change the jumper configuration to correspond with the n
118. n acquire gap free data by manipulating data buffers so that no gaps exist between the last sample of the current buffer and the first sample of the next buffer Note The number of DMA channels number of buffers and buffer size are critical to the board s ability to provide gap free data It is also critical that the application process the data in a timely fashion If you want to acquire gap free input data it is recommended that you specify a buffer wrap mode of none 0 using the WrapMode property When a buffer wrap mode of none is selected if you process the buffers and put them back on the ready queue in a timely manner the operation continues indefinitely When no buffers are available on the ready queue the operation stops and a QueueDone event is generated Software Architecture If you want to continuously reuse the buffers in the queues and you are not concerned with gap free data specify multiple buffer wrap mode 1 using the WrapMode property When multiple wrap mode is selected and no buffers are available on the ready queue the driver moves the oldest buffer from the done queue to the inprocess queue regardless of whether you have processed its data and overwrites the data in the buffer This process continues indefinitely unless you stop it When it reuses a buffer on the done queue the driver generates a BufferReused event If you want to perform gap free waveform generation analog output operations
119. n the following subsections Specifying the Gain for a Single Channel The simplest way to specify gain for a single channel is to specify the gain ina single value operation refer to page 112 for more information on single value operations You can also specify the gain for a single channel using a gain list ay described in the next section Specifying the Gain for One or More Channels You can specify the gain for one or more channels using a gain list The gain list parallels the channel list The two lists together are often referred to as the channel gain list or CGL To determine if the subsystem supports programmable gain use the GetSSCaps method specifying the OLSSC_SUP_PROGRAMGAIN capability If this method returns a non zero value the capability is supported To determine how many gains the subsystem supports use the GetSSCaps method specifying the OLSSC_NUMGAINS capability To list the gains supported by the subsystem use the EnumSSCaps function specifying the OL_LENUM_GAINS capability 109 Chapter 5 110 During runtime to list the gains available to the subsystem use the GainValues property to determine the number of gains available to the subsystem use the numGains property You specify the gain for each entry in the channel list using the GainList property Consider the following example Channel List Entry Channel Gain Description 0 5 Sample channel 5 usi
120. nd Visual C programmers see the online help in your programming environment Windows programming documentation XV About this Manual Where to Get Help Should you run into problems installing or using DTx EZ the Keithley Technical Support Department is available to provide technical assistance xvi Overview What 1s DIXEZ sitet td decide ated bande tae ah be eo heared ees 2 What You Need iiesink 0 sae y bane da eels oe eee eek coda oe 8 InstallatiOte sc 6s 2 icbes tose eee via airi gAn cideaederd cides 9 Adding DTx EZ Custom Controls to Your Project 10 Creating an Application 00 c cece 12 Using the DTx EZ Online Help 5 6 0 cee eee 13 Chapter 1 What is DTx EZ DTx EZ is a set of Object Linking and Embedding OLE controls that facilitate rapid data acquisition application development in Visual Basic and Visual C environments DTx EZ supplies the programming tools to transform Visual Basic and Visual C into a powerful data acquisition application development environment With DTx EZ you can quickly develop applications with analog and digital I O real time data display and a graphical user interface GUI while operating in a true Windows environment Conforms to the DT Open Layers Standard DTx EZ is fully compatible with DT Open Layers DT Open Layers is a set of open standards for developing integrated modular software under Microsoft Windows Because
121. ng 167 scan internal retrigger mode support 52 120 maximum per trigger or retrigger 52 119 multiple on trigger 118 retrigger extra mode support 52 121 setting up 175 triggered support 52 118 scan per trigger triggered scan mode support for 52 119 Scope example 42 service and support procedure 193 SetValidSamples function 66 in output buffering 177 SetValidSamples subroutine in buffer output operations 182 simultaneous operation 164 simultaneous sample and hold 103 107 support for 53 103 simultaneous start allocating list 164 ending operation 165 free list 165 pre starting subsystems on list 164 put subsystem on list 164 releasing list 98 starting subsystems on list 165 support for 51 164 SimultaneousPreStart subroutine 63 164 SimultaneousStart subroutine 63 165 single value example of 31 single buffer wrap mode support for 51 135 single ended quantity of channels 53 101 single ended channel input 101 support for 53 101 single ended channel type 101 SinglePoint property 73 example using 41 in plotting control operations 89 single value operation 112 performing 77 support for 50 112 software internal trigger 125 software gate 158 SRL subsystem restrictions on 94 start a simultaneous operation 165 Start method 61 example using 24 27 41 in continuous buffered input operations 80 in continuous buffered output operations 82 in continuous operations 113 in event counting operations 84 138 in frequency
122. ng a gain of 2 1 6 Sample channel 6 using a gain of 4 2 7 Sample channel 7 using a gain of 1 In this example a gain of 2 is applied to channel 5 a gain of 4 is applied to channel 6 and a gain of 1 is applied to channel 7 Note If your subsystem does not support programmable gain enter a value of 1 for all entries If your subsystem does not support the gain per channel capability set all entries in the gain list to the same value Software Architecture Filters This capability applies to A D subsystems only Depending on your subsystem you can specify a filter for each channel To determine if the subsystem supports a filter for each channel use the GetSSCaps method specifying the OLSSC_SUP_FILTERPERCHAN capability If this method returns a non zero value the capability is supported To determine how many filters the subsystem supports use the GetSSCaps method specifying the OLSSC_NUMFILTERS capability To list the cut off frequency of all filters supported by the subsystem use the EnumSSCaps method specifying the OLLENUM_FILTERS capability During runtime to list the filters available to the subsystem use the FilterValues property to determine the number of filters available to the subsystem use the numFilters property If the subsystem supports filtering per channel specify the filter for each channel using the FilterList property The filter is equal to or greater than a cut off frequenc
123. ns DTx EZ provides properties to perform the following general plotting operations e Plotting data this page e Specifying a grid page 168 and e Specifying markers page 169 The following subsections describe these operations in more detail Plotting Data When designing how your application displays data DTx EZ provides properties to affect the following e Data identification this page e Plotting mechanics page 167 and e Appearance page 167 DTx EZ provides a stripchart mode for additional flexibility as well see page 168 The following subsections describe these properties and the stripchart mode Data Identification Properties Before you can display data you must identify the type of information in the buffer Use the DataType property to identify the data as unsigned fixed point signed fixed point or floating point Use the numChannels property to specify the number of data channels in the buffer 166 Software Architecture Plotting Mechanics Properties When you plot data you must define where in the display to start plotting data Use the xStart property to set the plot s starting point Next you must define the data s scale microseconds seconds and so on the length of the x axis and the limits of the y axis Use the xAutoScale and yAutoScale properties to define these parameters automatically If you prefer you can manually define these parameters To change the plot s sc
124. nt 116 118 processor present on board 57 product support 191 Properties window 3 property 4 pseudo differential analog input 102 pulse output 162 high to low 162 low to high 162 performing operation 87 pulse type high to low support 55 162 low to high support 55 162 pulse width 162 PulseType property 60 162 in frequency measurement operations 142 in pulse output operations 88 PulseWidth property 60 162 in frequency measurement operations 142 in pulse output operations 88 PutSingleValue method 61 in single value operations 78 113 PutSubSysOnSSList subroutine 63 164 Q Queue property 62 129 133 in buffer input operations 178 179 in buffer output operations 182 in input buffering 176 in output buffering 177 QueueDone event in buffer input operations 178 in buffer output operations 181 with buffer wrap mode none 134 QueueSize property 62 in inprocess buffer transfer 180 QueueStopped event 116 131 in buffer input operations 178 in buffer output operations 181 207 Index 208 R range 108 maximum value during runtime 108 maximum voltage range available 108 minimum and maximum supported 108 minimum value during runtime 108 minimum voltage range available 108 per channel support 54 108 quantity of selections 54 108 quantity of voltage ranges available 108 specify 108 Range property 59 108 example using 23 in setting parameters 172 rate generation operation 144 support for 55 144 r
125. nteed s 100 Specifying the Channel Type 0 101 Contents Specifying a Single Channel 0 102 Specifying One or More Channels 102 Specifying the Channel List Size 103 Specifying the Channels in the Channel List 104 Inhibiting Channels in the Channel List 105 Specifying Synchronous Digital I O Values in the Channel List 0048 106 RANEES uomen aiii eaten ee cote tee teas 108 E e PPE EE EE EE EEA EE TE EATE 109 Specifying the Gain for a Single Channel 109 Specifying the Gain for One or More Channels 109 Fietse oieta E eee NOs use tosis Bahia ete at citadel 111 Data Flow Modes 0 0000 e eee eee 112 Single Value Operations 00 eee eee 112 Continuous Operations 0 eee eee eee 113 Continuous Post Trigger Mode 114 Continuous Pre Trigger Mode 115 Continuous About Trigger Mode 116 Triggered Scan Mode 0 0000 eee eee eee 118 Scan Per Trigger Mode 000000 119 Internal Retrigger Mode 00 ce aes 120 Retrigger Extra Mode 000008 121 Clock SOULCES sik eo ii Shh ESSE hd Baio bE oie 122 Internal Clock Source 000000 00005 122 External Clock Source 0 00 000 e cece eee 123 Extra Clock Source 0 00 eee eee eee 124 Trier Sources teris devout ot
126. of the current range setting MinRange Property Returns the minimum voltage value of the current range setting 59 Chapter 3 60 Table 7 Configuration Properties and Functions cont Feature Properties and Functions Description Resolution Resolution Property Sets and returns the number of bits of resolution Data Encoding Property Sets and returns the data Encoding encoding type Triggers Trigger Property Sets and returns the post trigger source PreTrigger Property Sets and returns the pre trigger source RetTrigger Property Sets and returns the retrigger source for retrigger extra retrigger mode Clocks ClockSource Property Sets and returns the clock source Frequency Property Sets and returns the frequency of the internal clock or a counter timer s output frequency ClockDivider Property Sets and returns the divider value applied to the external clock Counter Tim CTMode Property Sets and returns the ers counter timer mode CascadeMode Property Sets and returns the counter timer cascade mode GateType Property Sets and returns the gate type for the counter timer mode PulseType Property Sets and returns the pulse type for the counter timer mode PulseWidth Property Sets and returns the pulse output width for the counter timer mode Property Method Function and Subroutine Summary Operation Properties Me
127. only Note that you cannot use a buffer with single value operations A data buffer is a memory location that you allocate in host memory This memory location is used to store data for continuous input and output operations To determine if the subsystem supports buffers use the GetSSCaps method specifying the capability OLSSC_SUP_BUFFERING If this method returns a non zero value the capability is supported Buffers are stored on one of three queues the ready queue this page the inprocess queue page 130 or the done queue page 131 These queues are described in more detail in the following subsections Note In these subsections a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name Ready Queue For input operations the ready queue holds buffers that are empty and ready for input For output operations the ready queue holds buffers that you have filled with data and that are ready for output Allocate the buffers using the AllocBuffer o DmAllocBuffer or the CallocBuffer ol DmCallocBuffer function AllocBuffer olDmAllocBuffer allocates a buffer of samples where each sample is 2 bytes CallocBuffer o DmCallocBuffer allocates a buffer of samples of a specified size Software Architecture For analog input operations it is recommen
128. operations 182 BufferReused event in buffer input operations 178 in buffer output operations 181 with multiple buffer wrap mode 135 C calibration support for with software 57 CallocBuffer function 65 128 in inprocess buffer transfer 180 in input buffering 176 in output buffering 177 CascadeMode property 60 156 in event counting operations 83 in frequency measurement operations 85 in pulse output operations 87 cascading 156 support for 55 156 channel 100 differential 101 quantity of differential 54 101 quantity of DMA 51 136 quantity of I O 53 100 quantity of single ended 53 101 set parameters 173 single ended 101 specify gain for one or more 109 specify gain for single 109 specify one or more 102 specify single 102 specify type 101 support for filter per 54 111 support for range per 54 108 channel expansion 53 100 channel gain list adding channels to 104 configuration example 20 determine range for entry on 109 entry inhibit support 53 105 inhibiting entries on 105 quantity of entries on 52 103 random support 52 103 sequential support 52 103 set size of 103 setting up 102 173 specify gain for entry on 109 zero sequential support 53 103 ChannelList property 59 104 in setting channel parameters 173 ChannelType property 59 101 in setting parameters 172 ChartIt example 41 ClearError method 62 clock 154 cascading 156 external 123 155 support for 55 123 155 extra 124 157
129. operty Enables Disables the stripchart mode StripChartSize Property Sets and returns the maximum number of data points to store and that can be displayed per channel when in stripchart mode DataType Property Sets the type of data in the buffer object unsigned fixed point singed fixed point or floating point numChannels Property Specifies the number of data channels in the buffer object 70 Property Method Function and Subroutine Summary Grids The properties in Table 13 allow you to affect the display s grid appearance Table 13 Grid Properties Property Description GridAutoScale Property Enables Disables grid autoscale mode GridColor Property GridStyle Property Sets and returns the grid color Sets and returns the grid s line style GridXOn Property Displays Hides vertical grid lines GridXSpacing Property Sets vertical grid line spacing GridXStart Property Sets the position of the first vertical grid line GridYOn Property Displays Hides horizontal grid lines GridYSpacing Property Sets horizontal grid line spacing GridYStart Property Sets the position of the first horizontal grid line Markers The properties outlined in Table 14 allow you to affect the display s marker appearance Table 14 Marker Properties Property Description MarkerColor Property Sets the col
130. or for the horizontal and vertical markers MarkerH10On Property Displays Hides the first horizontal marker 71 Chapter 3 72 Table 14 Marker Properties cont Property Description MarkerH1Pos Property Sets the position of the first horizontal marker MarkerH2On Property Displays Hides the second horizontal marker MarkerH2Pos Property Sets the position of the second horizontal marker MarkerV1 Data Property Sets and returns the value of the data point at the location of the first marker MarkerV1On Property Displays Hides the first vertical marker MarkerV1Pos Property Sets the position of the first vertical marker MarkerV2Data Property Sets and returns the value of the data point at the location of the second marker MarkerV2On Property Displays Hides the second vertical marker MarkerV2Pos Property Sets the position of the second vertical marker x Axis Parameters The properties outlined in Table 15 allow you to affect a plot s x axis Table 15 x Axis Parameter Properties Property Description xAutoScale Property Enables Disables setting the xStart and xLength properties automatically for each new data buffer xLength Property Specifies the amount of data per channel to display xScale Property Sets the x axis scaling of the input data buffer xStart Property Sets
131. ot Custom Control to your form by selecting it from the toolbox and placing it on your form For information on adding a DTx EZ Custom Control to a project see page 10 Once added to your project you can select the DTx EZ Custom Control from the toolbox Configure your control object for the desired function by setting values in the Properties window Refer to Chapter 5 Software Architecture for more information Context sensitive online help is available for the DTx EZ Custom Controls as well To access online help simply press F1 and information related to the current operation appears on the screen Add code as needed using the Code window to Respond to user actions Change the properties at run time or Control data acquisition operations Refer to Chapter 2 Using the DTx EZ Examples for more information When you are ready to run your application outside your development environment create an executable file EXE by choosing Make EXE file from the File menu Note When you create and distribute applications that use the Data Acquisition Custom Control and DT Plot Custom Control review the licensing material included in the DTx EZ online help 12 Overview Using the DTx EZ Online Help This manual is intended to be used with the online help for DTx EZ The online help contains all of the specific reference information for each of the functions error codes and Windows messages
132. page 58 and e Operation properties methods functions and subroutines page 61 The following subsections briefly describe these tools Note For specific information about each of these tools refer to the DTx EZ online help See page 13 for information on launching the online help file Information Properties and Methods To determine the capabilities of your installed boards subsystems on each board and software use the information properties and methods listed in Table 4 47 Chapter 3 Table 4 Information Properties and Methods Query About Properties and Methods Description Boards and BoardList Property Lists all currently installed DT Open Devices Layers data acquisition boards devices numBoards Property Returns the number of DT Open Layers boards currently installed in the system EnumBoards Method Invokes the board enumeration sequence DeviceName Property Gets the full name of the specified device this name is set by the driver as part of the installation procedure hDev Property Returns the handle of the current subsystem s device Subsystems numSubSystems Property Returns the number of available subsystems for the selected DT Open Layers board SubSystemList Property Lists the subsystems available for the selected DT Open Layers board EnumSS Method Lists the names types and element number for each subsystem supported by the specified device
133. peration using an external C T clock source with an input frequency of 4 kHz a clock divider of 4 a low to high pulse type and a duty cycle of 50 The gate type does not matter for this example A 1 kHz square wave is the generated output 145 Chapter 5 Continuous Pulse Output Operation Starts External C T Clock Input Signal 4 kHz Pulse Output Signal 50 duty cycle Figure 35 Example of Rate Generation Mode with a 50 Duty Cycle Figure 36 shows the same example using a duty cycle of 75 146 Software Architecture Continuous Pulse Output Operation Starts External C T Clock Input Signal 4 kHz Pulse 75 duty cycle Output Signal Figure 36 Example of Rate Generation Mode with a 75 Duty Cycle Figure 37 shows the same example using a duty cycle of 25 147 Chapter 5 148 Continuous Pulse Output Operation Starts External C T Clock Input Signal 4 kHz Pulse Output Signal 25 duty cycle Figure 37 Example of Rate Generation Mode with a 25 Duty Cycle One Shot Use one shot mode to generate a single pulse output signal from the counter when the operation is triggered determined by the gate input signal You can
134. perations 182 olDmGetBufferSize 66 olDmGetDataBits 66 olDmGetDataWidth 66 olDmGetErrorString 66 olDmGetMaxSamples 66 olDmGetTimeDateStamp 66 olDmGetValidSamples 67 olDmReAllocBuffer 67 olDmReCallocBuffer 67 olDmSetValidSamples 66 olDspGetErrorString 66 olDspInputToVolts 68 olDspMagToDB 68 olDspRealFFT 68 olDsp VoltsToOutput 68 olDspWindow 68 OLSSC_CGLDEPTH 52 103 OLSSC_MAXDICHANS 54 101 OLSSC_MAXDIGITALIOLIST_ VALUE 53 106 OLSSC_MAXMULITISCAN 52 119 OLSSC_MAXSECHANS 53 101 OLSSC_NUMCHANNELS 53 100 OLSSC_NUMDMACHANS 51 136 Index OLSSC_NUMEXTRACLOCKS55 124 157 OLSSC_NUMEXTRATRIGGERS 55 127 OLSSC_NUMFILTERS 54 111 OLSSC_NUMGAINS 53 109 OLSSC_NUMRANGES 54 108 OLSSC_NUMRESOLUTIONS 54 100 OLSSC_SUP_ SIMULTANEOUS_START 51 164 OLSSC_SUP_ ZEROSEQUENTIAL_CGL 53 103 OLSSC_SUP_2SCOMP 54 99 OLSSC_SUP_ANALOGEVENTTRIG 35 127 OLSSC_SUP_BINARY 54 99 OLSSC_SUP_BUFFERING 51 128 OLSSC_SUP_CASCADING 55 156 OLSSC_SUP_CHANNELLIST_ INHIBIT 53 105 OLSSC_SUP_CONTINUOUS 50 114 OLSSC_SUP_CONTINUOUS_ABOUT TRIG 50 117 OLSSC_SUP_CONTINUOUS_ PRETRIG 50 115 OLSSC_SUP_CTMODE_COUNT 55 138 140 OLSSC_SUP_CTMODE_ONESHOT 55 148 OLSSC_SUP_CTMODE_ONESHOT_ RPT 55 151 OLSSC_SUP_CTMODE_RATE 55 144 OLSSC_SUP_DIFFERENTIAL 54 101 OLSSC_SUP_DIGITALEVENTTRIG 55 127 OLSSC_SUP_EXP2896 53 100 OLSSC_SUP_EXP727 53 100 OLSSC_SUP_EXTCLOCK 55 123 155 OLSSC_SUP_EXTERNTRIG 54 125 OLSSC_SUP_FIFO 57 OLSSC_SUP
135. performing output 81 support for 50 114 continuous pre trigger operation 115 support for 50 115 continuous pulse output support for 55 144 conventions used xiv conversion rate in internal retrigger mode 120 in retrigger extra mode 122 in scan per trigger triggered scan mode 120 CopyChannelFromBuffer subroutine 65 CopyChannelToBuffer subroutine 65 CopyFromBuffer subroutine 66 133 in buffer input operations 179 197 Index 198 CopyLongChannelFromBuffer subroutine 65 CopyLongChannelToBuffer subroutine 65 CopySingleChannelFromBuffer subroutine 65 CopySingleChannelToBuffer subroutine 66 CopyToBuffer subroutine 66 133 in buffer output operations 182 counter timer 137 cascading 156 support for 55 156 event counting operations 138 performing 83 support for 55 138 frequency measurement operations support for 85 140 high to low output pulse support for 55 162 low to high output pulse support 55 162 one shot operations 148 support for 55 148 pulse output operations performing 87 rate generation operations 144 support for 55 144 repetitive one shot operations 151 support for 55 151 CTMode function in frequency measurement operations 142 CTMode property 60 in event counting operations 83 138 in frequency measurement operations 85 140 142 in one shot operations 148 in pulse output operations 87 in rate generation operations 144 in repetitive one shot operations 151 CTReadEvents method 62 138 in ev
136. petitive one shot parameter 3 151 Chapter 5 152 Specify the C T clock source for the operation In repetitive one shot mode the internal C T clock source is more useful than an external C T clock source refer to page 154 for more information on specifying the C T clock source Specify the polarity of the output pulses high to low transitions or low to high transitions and the duty cycle of the output pulses refer to page 162 for more information Also specify the gate type that triggers the operation refer to page 157 for more information To start a repetitive one shot pulse output operation use the Start method When the one shot operation is triggered determined by the gate input signal a pulse is output When the board detects the next trigger another pulse is output This operation continues until you stop the operation using the Stop Abort or Reset method Reset stops the operation and reinitializes the subsystem after stopping it Some subsystems also allow you to pause the operation using the Pause method and resume the paused operation using the Continue method To determine if pausing is supported use the GetSSCaps method specifying the OLSSC_SUP_PAUSE capability If this method returns a non zero value the capability is supported Note Gates that occur while the pulse is being output may not detected by the board depending upon your board s counter timer See your driver documentation for deta
137. ples with your own code The following examples are provided A D Burst Example Acquires data to disk demonstrates channel gain list setup page 20 DAC Waveform Generator Example Generates sine square or triangle output waveforms It also demonstrates zooming in using the plot control page 25 Continuous A D Example Continuously samples and displays multiple data points page 29 Single Value Example Acquires a single value from an A D subsystem outputs a single value to a D A subsystem page 31 About Trigger Example Acquires data to disk from initialization until the trigger event occurs and then for one second after page 33 Digital I O Example Controls digital I O lines page 35 DDE Server and Client Example Moves data to or from other applications using Window s Dynamic Data Exchange page 37 Waveform Generator Example Demonstrates the use of counter timers to generate square waves page 39 Continuous FFT Example Computes and displays FFIs of the input data page 40 Using the DTx EZ Examples e ChartIt Example Demonstrates how to use the stripchart mode to display single points of data page 41 e Scope Example Generates and displays analog input channels including typical oscilloscope functions page 42 This chapter explains how to use each example To see actual signals being acquired connect a signal source to the analog inputs of your data acquisition board
138. ps method specifying the OLSSC_SUP_PLS_LOW2HIGH capability If this method returns a non zero value the capability is supported Specify the pulse output type using the PulseType property The duty cycle or pulse width indicates the percentage of the total pulse output period that is active A duty cycle of 50 then indicates that half of the total pulse is low and half of the total pulse output is high Specify the pulse width using the PulseWidth property Figure 42 illustrates a low to high pulse with a duty cycle of approximately 30 Software Architecture Active Pulse Width high pulse low pulse lt gt Total Pulse Period Figure 42 Example of a Low to High Pulse Output Type 163 Chapter 5 Simultaneous Operations If supported you can synchronize subsystems to perform simultaneous operations Note that you cannot perform simultaneous operations on subsystems configured for single value operations Note In this section a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name To determine if the subsystems support simultaneous operations use the GetSSCaps method for each subsystem specifying the OLSSC_SUP_SIMULTANEOUS_START capability If this method returns a non zero value the capabi
139. r 56 159 low level debounced gate 160 support for 56 160 low level gate 158 support for 56 158 low to high pulse output 162 support for 55 162 M MagToDB subroutine 68 marker 169 alter data at 169 enable disable 169 set line s color 169 set parameters 190 set position with code 169 set position with mouse 169 MarkerColor property 71 169 in setting marker parameters 190 MarkerH1Data property in setting marker parameters 190 MarkerH10n property 71 169 in setting marker parameters 190 MarkerH1Pos property 72 169 in setting marker parameters 190 MarkerH2Data property in setting marker parameters 190 MarkerH2On property 72 169 in setting marker parameters 190 MarkerH2Pos property 72 169 in setting marker parameters 190 MarkerV1Data property 72 169 in setting marker parameters 190 MarkerV10On property 72 169 in setting marker parameters 190 MarkerV1Pos property 72 169 in setting marker parameters 190 MarkerV2Data property 72 169 in setting marker parameters 190 MarkerV2On property 72 169 in setting marker parameters 190 MarkerV2Pos property 72 169 in setting marker parameters 190 MaxRange property 59 108 MaxRangeValues property 49 76 108 MeasureDone event in frequency measurement operations 86 141 MeasureFrequency method 62 140 in frequency measurement operations 86 method 5 MinRange property 59 108 MinRangeValues property 50 76 108 MouseXPos property 73 169 MouseYPos property 73 169 mu
140. r represents the A D subsystem and the Client represents the D A subsystem The Server continuously updates the input data values in the scroll bar and text box Follow these steps 1 Click Copy Link on the Server form to copy the data link to the clipboard 2 Click Paste Link on the Client form to continuously output data from the clipboard and to display it in the Client form s scroll bar and text box Note that the Paste Link command has toggled to Close DDE Link 3 Click Close DDE Link to stop the data exchange into the D A subsystem Using the DTx EZ Examples Waveform Generator Example This example wavegen vbp or wavegen mdp generates a square wave from counter timer 0 Set the frequency by entering the value in hertz in the text box at runtime as shown in Figure 13 Ea Square Wave Generator of xi Frequency Hz Figure 13 Setting the Waveform Frequency 39 Chapter 2 40 Continuous FFT Example This example contfft vbp or contfft mdp acquires data from a single analog input channel performs frequency analysis on the data using an FFT Fast Fourier Transform and plots the result of the analysis You could use this example for vibration analysis to calculate transfer functions or to monitor the frequency content of an audio signal Click Start to begin the FFT click Stop to end it A typical FFT display is shown in Figure 14 Cont
141. ra C T Clock Source 0 0 00 c eee eee 157 Gate ly pes lt vsadus siceewh adie bade rhe nd bdeie beneath ice 157 Software Gate Type 0 66 cece eee eae 158 High Level Gate Type 0000 158 Low Level Gate Type 0 6 ccc eee e eens 158 xi Contents xii Low Edge Gate Type 0 6 6 cece cece eens 159 High Edge Gate Type 000000 159 Any Level Gate Type 0000008 159 High Level Debounced Gate Type 160 Low Level Debounced Gate Type 160 High Edge Debounced Gate Type 160 Low Edge Debounced Gate Type 161 Level Debounced Gate Type 008 161 Pulse Output Types and Duty Cycles 162 Simultaneous Operations 00 00 eee ee 164 Plot Control Operations 6 cece cece eee 166 Plotting Data cs ods sasaerieds orteloeded aout ete s 166 Data Identification Properties 4 166 Plotting Mechanics Properties 4 167 Appearance lt 1 100 2rhocuriticstoe i petit n Eta ekaa 167 Stripchart Mode 6 cece eee 168 Specifying a Grid 0 168 Specifying Mark rS sss ro cc 0cscrsecrsee ceewnseean s 169 Appendix A Flowcharts for Substeps 171 Chapter 6 Product Support 202eeeeeeeee 191 General Checklist 0 0000 iaei eaa k nE Eee eens 192 Service and Support
142. re numbered sequentially When a new Revision is created all Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual Each new Revision includes a revised copy of this print history page Revision A Document Number DTXEZ 903 O1A cccccecccssessceseeseeseessecseeeseeseceeeseeseeeenseeseeneeeeeeas January 2005 All Keithley product names are trademarks or registered trademarks of Keithley Instruments Inc Other brand and product names are trademarks or registered trademarks of their respective holders Nema Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation Although some in struments and accessories would normally be used with non haz ardous voltages there are situations where hazardous conditions may be present This product is intended for use by qualified personnel who recog nize shock hazards and are familiar with the safety precautions re quired to avoid possible injury Read and follow all installation operation and maintenance information carefully before using the product Refer to the manual for complete product specifications If the product is used in a manner not specified the protection pro vided by the product may be impaired The types of product users are Responsible body is the individual or group responsible for the use and maintenance of equipment for ensuring that
143. red OLSSC_SUP_TRIGSCAN Non zero if subsystem supports Scan Mode triggered scans OLSSC_MAXMULTISCAN Maximum number of scans per trigger or retrigger supported by the subsystem OLSSC_SUP_RETRIGGER_ SCAN_PER_TRIGGER Non zero if subsystem supports scan per trigger triggered scan mode retrigger is the same as the initial trigger source OLSSC_SUP_RETRIGGER_ INTERNAL Non zero if subsystem supports internal retriggered scan mode retrigger source is on the board initial trigger is any available trigger source OLSSC_SUP_RETRIGGER_ EXTRA Non zero if subsystem supports retrigger extra triggered scan mode retrigger can be any supported trigger source initial trigger combinations may be limited by the driver Channel Gain List OLSSC_CGLDEPTH Number of entries in channel gain list OLSSC_SUP_RANDOM_CGL Non zero if subsystem supports random channel gain list setup OLSSC_SUP_SEQUENTIAL_ CGL Non zero if subsystem supports sequential channel gain list setup Property Method Function and Subroutine Summary Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Channel Gain OLSSC_SUP_ Non zero if subsystem supports List cont ZEROSEQUENTIAL_CGL sequential channel gain list setup starting with channel zero OLSSC_SUP_ Non zero if subsystem supports SIMULTANEOUS_SH sim
144. rogrammers They provide a set of object oriented buffer management facilities When a buffer object is created a buffer handle hbuf is returned This handle is used in all subsequent buffer manipulation Note The buffer management functions and subroutines listed in Table 9 are intended for use by both application and system programmers They provide a set of object oriented buffer management facilities When a buffer object is created a buffer handle hbuf is returned This handle is used in all subsequent buffer manipulation Property Method Function and Subroutine Summary Note Because of the differences in the two compliers the Visual Basic and Visual C libraries exist as separate entities however they are nearly identical in functionality In Table 9 a function or subroutine name followed by a parenthetical italicized name indicates that Visual Basic and Visual C each have their own tools In such cases the Visual C name appears in italics following the Visual Basic name For specific information about each of these functions and subroutines refer to the DTx EZ online help See page 13 for information on launching the online help file Table 9 Buffer Management Functions and Subroutines Functions and Subroutines Description AllocBuffer Function olDmAllocBuffer CallocBuffer Function olDmCallocBuffer CopyChannelFromBuffer Subroutine CopyLongChannelFromBuffer Subroutine
145. rom an analog input channel or an external analog signal attached to the device An analog trigger occurs when the device detects a transition from a negative to positive value that crosses a threshold value The threshold level is generally set using a D A subsystem on the device To determine if the subsystem supports analog threshold triggering positive polarity use the GetSSCaps method specifying the capability OLSSC_SUP_THRESHTRIGPOS If this method returns a non zero value the capability is supported Refer to your board device driver documentation for a description of this trigger source External Analog Threshold Negative Trigger Source An external analog threshold negative trigger is generally either an analog signal from an analog input channel or an external analog signal attached to the device An analog trigger event occurs when the device detects a transition from a positive to negative value that crosses a threshold value The threshold level is generally set using a D A subsystem on the device To determine if the subsystem supports analog threshold triggering negative polarity use the GetSSCaps method specifying the capability OLSSC_SUP_THRESHTRIGNEG If this method returns a non zero value the capability is supported Refer to your board device driver documentation for a description of this trigger source Software Architecture Analog Event Trigger Source For this trigger source a trigger is gen
146. rty 57 94 in continuous buffered input operations 79 in continuous buffered output operations 81 in event counting operations 83 in frequency measurement operations 85 in pulse output operations 87 in single value operations 77 support 191 SyncD1OUsage property 59 106 in setting channel parameters 173 synchronous digital I O setting up a channel gain list for 106 synchronous digital output channel list maximum value 53 106 Index synchronous digital output operation support for 53 106 T technical support xvi 191 193 timer event trigger 127 support for 55 127 trigger acquire data before 115 acquire data before and after 116 acquire or output data continuously on 114 analog event 127 support for 55 127 digital event 127 support for 55 127 external analog threshold negative 126 support for 54 126 external analog threshold positive 126 support for 54 126 external digital TTL 125 support for 54 125 extra 127 internal retrigger mode 120 maximum scans per 52 119 quantity of extra 55 127 restrictions 152 retrigger extra mode 121 scan CGL multiple times on 118 scan per trigger triggered scan mode 119 software internal 125 support for 54 125 specifying 174 synchronizing 164 timer event 127 support for 55 127 Trigger property 60 125 example using 23 in continuous post trigger mode 114 in continuous about trigger mode 117 in continuous pre trigger mode 116 in setting trigger parameters 1
147. s E eee eset ohaeds deanna es 71 MAPK CRS tie toe tis aacite ati Na ehe le ithe ite ceed Biba e 71 x Axis Parameters 2 0 0 AE eens 12 y Aods Patameters soccciecssosedrapes esse EEEE i 73 Plotting Operation Control Parameters 73 Chapter 4 Programming Flowcharts 75 Introduction eaae ls eb ata ee ees 76 Single Value Operations 0 0 6 2 6c cece 77 Continuous Buffered Input Operations 79 Continuous Buffered Output Operations 81 Event Counting Operations 6 6 6 83 Frequency Measurement Operations 00005 85 Pulse Output Operations 0 00 c eee eee 87 Plotting Control Operations 6 c cece eee ee 89 Chapter 5 Software Architecture 91 troduction eiia seei a do Medien EE nila datas E EE end bus 92 System Operations serieren a eee eee 93 Initializing and Specifying a Board 45 93 Specifying a Subsystem 000s 94 Configuring a Subsystem 0 00000 000008 95 Handling Events 00 01944 cies ees euecieee nn o eea na 96 Handling Errors eere reeg gnere sre korne pniyit piene tes 96 Halting the Operation 00 00 e eee eee 98 Analog and Digital I O Operations 0 99 Data Encoding 1 ere kekere enie nae peas 99 Resoluti ns e irerercere sesi nhier tarir dees Pease dees 100 Channels sersa ncisancseulecsecs nieeicegeeavein
148. server vbp DDE Client dde client vbp Wave Generator wavegen wavegen vbp About Trigger abouttrigger abouttrigger vbp Continuous FFT contfft contfft vbp Chartit chartit chartit vbp Scope scope scope vbp 4 Select Run gt Start to run each example 18 Using the DTx EZ Examples Opening the Examples from within Visual C To customize the DTx EZ example code for your own application you must open the example s build file MDP from within Visual C as follows 1 Start your operating system and start Visual C 2 Choose File gt Open Workspace 3 Select the examples from the directory DTx EZ examples cpp The examples have a MDP extension Table 2 Visual C Example Programs and Their MDP Files Example Directory A D Burst adburst adburst mdp DAC Waveform dacwave dacwave mdp Continuous A D contdisp contdisp mdp Single value sv sv mdp Digital I O dio dio mdp DDE Server dde server server mdp DDE Client dde client client mdp Wave Generator wavegen wavegen mdp About Trigger abouttrigger abouttrigger mdp Continuous FFT contfft contfft mdp Chartit chartit chartit mdp Scope scope scope mdp 4 Select Run gt Start to run each example 19 Chapter 2 A D Burst Example This example adburst vbp or adburst mdp samples multiple analog input channels and places the resulting data in a disk file for archiving and post acquisition an
149. setting grid parameters 189 H handle 94 hdass 94 hDass property 50 hDev property 48 help online help 12 13 technical support xvi high edge debounced gate 160 support for 56 161 high edge gate 159 support for 56 159 high level debounced gate 160 support for 56 160 high level gate 158 support for 56 158 high to low output pulse 162 support for 55 162 I InhibitList property 59 105 in setting channel parameters 173 inprocess queue 130 support for write to 51 131 transfer data from 180 InputToVolts subroutine 68 internal software gate support for 56 158 internal clock 122 155 support for 55 122 155 internal retriggered scan mode 120 support for 52 120 internal software trigger support for 54 125 interrupt 135 support for 56 135 L LastError property 50 LastErrorDescription property 50 level debounced gate 161 support for 56 161 level gate 159 support for 56 159 line enable disable relative spacing on grid 168 set color for grid 168 set color for marker 169 set color for plot 167 set style for grid 168 set style for plot 167 set width for plot 167 show hide on grid 168 space on grid 168 LineStyle property 70 167 in setting plot appearance 185 LineWidth property 70 167 in setting plot appearance 185 Index ListSize property 59 103 in setting channel parameters 173 LongtoFreg Param macro 86 141 low edge debounced gate 161 support for 56 161 low edge gate 159 support fo
150. specify single buffer wrap mode 2 using the WrapMode property When single wrap mode is specified a single buffer is reused continuously In this case the driver moves the buffer from the ready queue to the inprocess queue and outputs the data from the buffer However when the buffer is emptied the driver or board reuses the data and continuously outputs it This process repeats indefinitely until you stop it When you stop the operation the buffer is moved to the done queue No messages are posted in this mode until you stop the operation To determine the buffer wrap modes available for the subsystem use the GetSSCaps method specifying the capability OLSSC_SUP_WRPSINGLE for single wrap mode or OLSSC_SUP_WRPMULTIPLE for multiple wrap mode If this method returns a non zero value the capability is supported DMA Resources You cannot use DMA or interrupt resources for single value operations To determine if your subsystem supports interrupt resources use the GetSSCaps method specifying the capability OLSSC_SUP_INTERRUPT If this method returns a non zero value the capability is supported 135 Chapter 5 136 Note If supported all DT Open Layers boards use interrupt resources Generally you specify interrupt resources on the board itself and in the driver configuration dialog To determine if the subsystem supports DMA resources use the GetSSCaps method specifying the capability OLSSC_NUMDMACHANS
151. splay To turn stripchart mode on set the StripChartMode property to TRUE To set the maximum number of data points to store and display per channel use the StripChartSize property Specifying a Grid A grid is the underlying framework of lines on which the data is plotted You can change the grid s appearance independently from the data s appearance You can also choose not to display a grid at all You can change the grid s overall color with the GridColor property You can change the grid s overall line style dashed dotted and so on with the GridStyle property Use the GridXStart and Grid YStart properties to set the first line on the x and y axes Use the GridXSpacing and the GridYSpacing to draw the rest of the grid lines You can keep the x and y axis lines from displaying with the GridXOn and the GridYOn properties Finally in response to zooming in or out of a display or to differing buffer sizes you can choose to keep the units between the gridlines constant or to increase or decrease the space between the grid lines using the GridAutoScale property Software Architecture Specifying Markers Markers are lines that you can overlay ona plot as reference points they are unaffected by the plotting of data DTx EZ allows you to define and place up to two pairs of markers Each pair has a horizontal and vertical line although you may place one or two horizontal or vertical lines alone if you prefer
152. t on the done queue Reset also reinitializes the subsystem to a known state and flushes all buffers to the done queue Flowcharts for Substeps Set Plot Appearance d BackColor Property Set the plot s background color Set each plot line s color each channel may be Plotting a represented by a different single Palette Property color if you wish g p channel Yes y ForeColor Property Set the plot line s color LineStyle Property Change the plot line s width Yv d LineWidth Property 3 Change the plot line s width 185 Appendix A Set Pre Operation Parameters Using stripchart mode No bi StripChartMode Property StripChartSize Property v DataType Property v lt numChannels Property 186 Set the StripChartMode property to TRUE Set the number of data points you wish to plot the default size is 1000 Indicate the data type in the buffer Indicate the number of channels to plot Flowcharts for Substeps Set the Plot s x Axis xScale Property Set the plot s scale Autoscale x axis lot s starti int xStart Property Set the plot s starting poin Set the number of data xLength Property points to display xAutoScale Property Enable the autoscale feature for the x axis by setting
153. the process continuously until either the allocated buffers are filled or you stop the operation Refer to page 102 for more information on channel lists refer to page 128 for more information on buffers Software Architecture Figure 24 illustrates continuous post trigger mode using a channel list of three entries channel 0 channel 1 and channel 2 In this example post trigger analog input data is acquired on each clock pulse of the A D sample clock refer to page 122 for more information on clock sources The board wraps to the beginning of the channel list and repeats continuously Chano Chan2 ChanO Chan2 ChanO Chan2 ChanO Chan2 Chan 1 Chan 1 Chan 1 Chani ep LILI Sample Clock Post trigger data acquired Post trigger event occurs continuously Figure 24 Continuous Post Trigger Mode Continuous Pre Trigger Mode Use continuous pre trigger mode when you want to acquire data before a specific external event occurs To determine if the subsystem supports continuous pre trigger mode use the GetSSCaps method specifying the OLSSC_SUP_CONTINUOUS_PRETRIG capability If this method returns a non zero value the capability is supported Specify the operation mode as continuous pre trigger 4 using the DataFlow property Pre trigger acquisition starts when the device detects the pre trigger source and stops when the board detects an external post trigger source
154. the capability is supported Note that you cannot use triggered scan mode with single value operations To enable or disable triggered scan mode use the TriggeredScan property Software Architecture To determine the maximum number of times that the board can scan the channel gain list per trigger use the GetSSCaps method specifying the OLSSC_MAXMULTISCAN capability Use the MultiscanCount property to specify the number of times to scan the channel gain list per trigger DTx EZ defines the following retrigger modes for a triggered scan these retrigger modes are described in the following subsections e Scan per trigger page 119 e Internal retrigger page 120 and e Retrigger extra page 121 Note If your device driver supports it retrigger extra is the preferred triggered scan mode Scan Per Trigger Mode Use scan per trigger mode if you want to accurately control the period between conversions of individual channels and retrigger the scan based on an internal or external event In this mode the retrigger source is the same as the initial trigger source To determine if the subsystem supports scan per trigger mode use the GetSSCaps method specifying the OLSSC_SUP_RETRIGGER_SCAN_PER_TRIGGER capability If this method returns a non zero value the capability is supported Specify the retrigger mode as OL_TRIGGER_SCAN_PER_TRIGGER using the RetriggerMode property 119 Chapter 5 120 When it
155. the first available buffer Buffer 1 in this case puts it on the inprocess queue and starts filling it with data The queues appear as shown in Figure 28 Ready Queue Buffer 2 Buffer 3 y Inprocess Queue Buffer 1 Done Queue Figure 28 Example of the Inprocess Queue If you want to transfer data from a partially filled buffer you can use the FlushFromBufferInProcess o DaFlushFromBufferInprocess subroutine to transfer data from the buffer on an inprocess queue to another buffer you allocate if this capability is supported Typically you would use this function when your data acquisition operation is running slowly Software Architecture To determine if the subsystem supports transferring data from a buffer on the inprocess queue use the GetSSCaps method specifying the OLSSC_SUP_INPROCESS_FLUSH capability If this method returns a non zero value this capability is supported Done Queue Once the data acquisition board has filled the buffer for input operations or emptied the buffer for output operations the buffer is moved from the inprocess queue to the done queue Then either the BufferDone event is generated when the buffer contains post trigger data or in the case of pre and about trigger acquisitions a PreTrigBufferDone event is generated when the buffer contains pre trigger data Note When the pre trigger acquisition operation completes or you stop an acquisi
156. the first data point to be displayed Property Method Function and Subroutine Summary y Axis Parameters The properties outlined in Table 16 allow you to affect a plot s y axis Table 16 x Axis Parameter Properties Property Description yAutoScale Property Enables Disables setting the yMin and yMax properties automatically for each new data buffer yMax Property Specifies the upper limit of the plot s y axis yMin Property Specifies the lower limit of the plot s y axis Plotting Operation Control Parameters The properties outlined in Table 17 allow you to affect how the DT Plot Custom Control handles and plots data Table 17 Plotting Operation Control Parameter Properties Property Description Buffer Property Plots a buffer of data ForceRepaint Property Enables Disables the repainting mode MouseXPos Property Returns the x coordinate of the current mouse position MouseYPos Property Returns the y coordinate of the current mouse position SinglePoint Property Plots a single point in stripchart mode UpdateMode Property Enables Disables the plot update mode 73 Chapter 3 74 B Programming Flowcharts IntHO MUCH OM sg is a e a a op aieas 76 Single Value Operations 000 e eee eee 72 Continuous Buffered Input Operations 79 Continuous Buffered Output Operations 81 Event
157. thods Functions and Subroutines Once you have set the parameters of a subsystem use the operation properties methods functions and subroutines listed in Table 8 Note that italic text indicates a the name of an alternate function call Table 8 Operation Properties Methods Functions and Subroutines Properties Methods Operation Functions and Subroutines Description Single Value GetSingleValue Method Reads a single input value from Operations the specified subsystem channel PutSingleValue Method Writes a single output value to the specified subsystem channel All Other Config Method After setting up a specified Operations subsystem using the configuration tools configures the subsystem with new parameter values Start Method Starts the operation for which the subsystem has been configured Pause Method Pauses a continuous operation on the subsystem Continue Method Continues the previously paused operation on the subsystem Stop Method Stops the operation and returns the subsystem to the ready state Abort Method Stops the subsystem s operation immediately Reset Method Causes the operation to terminate immediately and reinitializes the subsystem 61 Chapter 3 Table 8 Operation Properties Methods Functions and Subroutines cont Properties Methods Operation Functions and Subroutines Description Buffer Flus
158. tion 0 4 Sample channel 4 1 5 Sample channel 5 2 4 Sample channel 4 again 3 6 Sample channel 6 In this example channel 4 is sampled first followed by channel 5 channel 4 again then channel 6 Software Architecture Inhibiting Channels in the Channel List If supported you can set up a channel inhibit list this feature is useful if you want to discard values acquired from specific channels as is typical in simultaneous sample and hold applications To determine if a subsystem supports a channel inhibit list use the GetSSCaps method specifying the OLSSC_SUP_CHANNELLIST_INHIBIT capability If this method returns a non zero value the capability is supported Using the InhibitList property you can enable or disable inhibition for each entry in the channel list If enabled the acquired value is discarded after the channel entry is sampled if disabled the acquired value is stored after the channel entry is sampled Consider the following example Channel List Channel Inhibit Entry Channel Value Description 0 11 True Sample channel 11 and discard the value 1 10 False Sample channel 10 and store the value 2 9 True Sample channel 9 and discard the value 3 8 False Sample channel 8 and store the value In this example the values acquired from channels 11 and 9 are discarded and the values acquired from channels 10 and 8 are stored 105 Chapter 5 10
159. tion the QueueStopped event is also generated Continuing with the previous example the queues appear as shown in Figure 29 when you get the first BufferDone event Ready Queue Buffer 2 Buffer 3 Inprocess Queue Y Done Queue Buffer 1 Figure 29 Example of the Done Queue 131 Chapter 5 132 Then the driver moves Buffer 2 from the ready queue to the inprocess queue and starts filling it with data When Buffer 2 is filled Buffer 2 is moved to the done queue and another BufferDone event is generated The driver then moves Buffer 3 from the ready queue to the inprocess queue and starts filling it with data When Buffer 3 is filled Buffer 3 is moved to the done queue and another BufferDone event is generated Figure 30 shows how the buffers are moved Ready Queue Inprocess Queue J Done Queue Buffer 1 Buffer 2 Buffer 3 Figure 30 How Buffers are Moved to the Done Queue If you transferred data from an inprocess queue to a new buffer using the FlushFromBufferInprocess o DaFlushFromBufferInprocess subroutine the new buffer is put on the done queue for your application to process When the buffer on the inprocess queue finishes being filled this buffer is also put on the done queue the buffer contains only the samples that were not previously transferred Software Architecture Buffer and Queue Management Eac
160. to determine how many DMA channels are supported If supported these channels must be specified in the driver configuration dialog In addition specify OLSSC_SUP_GAPFREE_NODMA for gap free data using no DMA channels OLSSC_SUP_GAPFREE_SINGLEDMA for gap free data using one DMA channel or OLSSC_SUP_GAPFREE_DUALDMA for gap free data using two DMA channels If this method returns a non zero value the capability is supported Use the DmaUsage property to specify the number of DMA channels to use Note DMA channels are a limited resource and the request may not be honored if the requested number of channels is unavailable For example suppose that a device that supports both A D and D A subsystems provides hardware for two DMA channels and that one DMA channel is currently allocated to the A D subsystem In this case a request to the D A subsystem to use two DMA channels will fail Software Architecture Counter Timer Operations Each user counter timer channel accepts a clock input signal and gate input signal and outputs a clock output signal also called a pulse output signal as shown in Figure 32 Clock Input Signal internal external or gt internally cascaded Counter Timer e Gate Input Signal software or external input Figure 32 Counter Timer Channel Pulse Output Signal Each counter timer channel corresponds to a counter
161. tom Control module and or DTPlot32 OLE Custom Control module then click OK 4 Choose Project gt Add Module The Add Module dialog box appears 5 Select the Existing tab 6 Select OLMEMDEFS BAS OLDEFS BAS and or OLDSPDEFS BAS from the DTx EZ INCLUDE directory and click Open 10 Overview When the DTx EZ custom controls are loaded the DTACQ32 and DTPLOT32 icons appear in the Toolbox as follows Adding to a Visual C 6 0 Project Before you begin using the DT EZ add the DTx EZ Data Acquisition and DT Plotting Custom Controls 1 Start Windows 95 and launch Microsoft Visual C 6 0 2 Create a new MFC project using the application wizard Ensure you add support for ActiveX controls in Step 2 3 Select Project gt Add to Project gt Components and Controls The Component and Controls Gallery appears 4 Double click the Registered ActiveX Controls folder 5 Select the DTPlot32 Control and click Insert The program prompts you to insert the component and to confirm the creation of a wrapper class for accessing the control through Visual C 6 Repeat step 5 for the DTAcq32 Control 11 Chapter 1 Creating an Application You can use the Data Acquisition Custom Control and DT Plot Custom Control just like other ActiveX or OLE custom controls to integrate data acquisition into your Windows application Create your application as follows 1 Add the Data Acquisition or DT Pl
162. turn them on and off the new values are written to the DOUT subsystem 35 Chapter 2 Note The actual read and write rate is set to 100 ms by the timer control The timer control runs from the system clock 36 Using the DTx EZ Examples DDE Server and Client Examples The DDE server and client examples demonstrate the use of Windows Dynamic Data Exchange DDE between applications In Visual Basic these examples server vbp and client vbp reside in the same directory in Visual C these examples server mdp and client mdp reside in their own directories In either platform the two examples are designed to be used together These examples allow you to send acquired voltage values to other applications for analysis and display and to move voltage values calculated in another application to DTx EZ for conversion and output You could use this example for report generation and data analysis or data generation using any Windows spreadsheet word processing or analysis package For more information on DDE operation refer to your development environment s programming guide Open the Server and Client examples to display the forms shown in Figure 12 Ea Server is an Input Subsyst l E3 Ea Client is an Output Subsystem M E3 Copy Link Paste Link 4 10 Volts 4 10 Volts ep pd Figure 12 DDE Forms 37 Chapter 2 38 These forms allow you to share data between the two examples The Serve
163. ty Method Function and Subroutine Summary Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Simultaneous OLSSC_SUP_ Non zero if subsystem can be Operations SIMULTANEOUS_ START started simultaneously with another subsystem on the device Pausing OLSSC_SUP_PAUSE Non zero if subsystem supports Operations pausing during continuous operation Windows OLSSC_SUP_POSTMESSAGE Non zero if subsystem supports Messaging asynchronous operations Buffering OLSSC_SUP_BUFFERING Non zero if subsystem supports buffering OLSSC_SUP_WRPSINGLE Non zero if subsystem supports single buffer wrap mode OLSSC_SUP_WRPMULTIPLE Non zero if subsystem supports multiple buffer wrap mode OLSSC_SUP_INPROCESS_ Non zero if subsystem supports FLUSH copying a buffer on subsystem s inprocess queue DMA OLSSC_NUMDMACHANS Number of DMA channels supported OLSSC_SUP_GAPFREE_ Non zero if subsystem supports NODMA gap free continuous operation with no DMA DMA cont OLSSC_SUP_GAPFREE_ Non zero if subsystem supports SINGLEDMA gap free continuous operation with a single DMA channel OLSSC_SUP_GAPFREE_ DUALDMA Non zero if subsystem supports gap free continuous operation with two DMA channels 51 Chapter 3 52 Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Trigge
164. ty is supported Specify the clock source as external using the ClockSource property Then use the ClockDivider property to specify the clock divider used to determine the frequency at which to pace the operation the clock input source divided by the clock divider determines the frequency of the clock signal 123 Chapter 5 124 To determine the maximum clock divider that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MAXCLOCKDIVIDER capability To determine the minimum clock divider that the subsystem supports use the GetSSCapsEx method specifying the OLSSCE_MINCLOCKDIVIDER capability Extra Clock Source Your device driver may define extra clock sources that you can use to pace acquisition or output operations To determine how many extra clock sources are supported by your subsystem use the GetSSCaps method specifying the OLSSC_NUMEXTRACLOCKS capability Refer to your board driver documentation for a description of the extra clock sources The extra clock sources may be internal or external Refer to the previous sections for information on how to specify internal and external clocks and their frequencies or clock dividers Trigger Sources DTx EZ defines the following trigger sources e Software internal trigger this page e External digital TTL trigger page 125 e External analog threshold positive trigger page 126 e External analog threshold negative trigger page 126
165. ultaneous sample and hold operations The channel gain list must be set up with both a sample channel and a hold channel OLSSC_SUP_CHANNELLIST_ Non zero if subsystem supports INHIBIT channel gain list entry inhibition Gain OLSSC_SUP_PROGRAMGAIN Non zero if subsystem supports programmable gain OLSSC_NUMGAINS Number of gain selections Synchronous OLSSC_SUP_ Non zero if subsystem supports Digital I O SYNCHRONOUS_DIGITALIO synchronous digital output operations OLSSC_MAXDIGITALIOLIST_ Maximum value for synchronous VALUE digital output channel list entry I O Channels OLSSC_NUMCHANNELS Number of I O channels Channel Type OLSSC_SUP_SINGLEENDED Non zero if subsystem supports single ended inputs OLSSC_MAXSECHANS Number of single ended channels OLSSC_SUP_DIFFERENTIAL Non zero if subsystem supports differential inputs OLSSC_MAXDICHANS Number of differential channels Filters OLSSC_SUP_ FILTERPERCHAN Non zero if subsystem supports filtering per channel OLSSC_NUMFILTERS Number of filter selections 53 Chapter 3 54 Table 5 Capabilities to Query with the GetSSCaps Method cont Query About Capability Method Returns Ranges OLSSC_NUMRANGES Number of range selections OLSSC_SUP_ Non zero if subsystem supports RANGEPERCHANNEL different range settings for each channel Resolution OLSSC_SUP_ Non zero if subsystem supports SWRESOLUT
166. unction and Subroutine Summary DT Plot Custom Control The DT Plot Custom Control provides the following categories of plotting control properties e Plot appearance this page e Plot pre display operational parameters page 70 e Grids page 71 e Markers page 71 e x Axis parameters page 72 e y Axis parameters page 73 and e Plotting operation control parameters page 73 The following subsections briefly describe these properties Note For specific information about each of these properties refer to the DTx EZ online help See page 13 for information on launching the online help file Plot Appearance The properties outlined in Table 11 allow you to affect the display s basic appearance 69 Chapter 3 Table 11 Plot Appearance Property Description BackColor Sets the display s background color Microsoft standard property ForeColor Sets the plot lines colors Microsoft standard property Palette Property Sets the color of each channel s plot line individually LineStyle Property Sets the style of the data plotting lines LineWidth Property Sets the width of the data plotting lines Plot Pre Display Operational Parameters The properties outlined in Table 12 allow you to define how the plot functions and outputs data Table 12 Plot Pre Display Operational Parameter Properties Property Description StripChartMode Pr
167. unter timer operation when the external gate signal is low and debounced Note that this gate type is used only for event counting frequency measurement and rate generation refer to page 138 for more information on these modes To determine if the subsystem supports a low level debounced external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_LOW_LEVEL_DEBOUNCE capability If this method returns a non zero value the capability is supported High Edge Debounced Gate Type A high edge debounced gate type triggers a counter timer operation on the rising edge of the external gate signal the signal is debounced Note that this gate type is used only for one shot and repetitive one shot mode refer to page 138 for more information on these modes 160 Software Architecture To determine if the subsystem supports a high edge debounced external gate input use the GetSSCaps method specifying the OLSSC_SUP_GATE_HIGH_EDGE_DEBOUNCE capability If this method returns a non zero value the capability is supported Low Edge Debounced Gate Type A low edge debounced gate type triggers a counter timer operation on the falling edge of the external gate signal the signal is debounced Note that this gate type is used only for one shot and repetitive one shot mode refer to page 138 for more information on these modes To determine if the subsystem supports a low edge debounced external gate input use the GetSSC
168. upports simultaneous sample and hold mode use the GetSSCaps method specifying the OLSSC_SUP_SIMULTANEOUS_SH capability If this method returns a non zero value the capability is supported You must enter at least two channels in the channel list Generally the first channel is the sample channel and the remaining channels are the hold channels The following subsections describe how to specify channels in a channel list Specifying the Channel List Size To determine the maximum size of the channel list for the subsystem use the GetSSCaps method specifying the OLSSC_CGLDEPTH capability Use the ListSize property to specify the size of the channel list 103 Chapter 5 104 Note The OLSSC_CGLDEPTH capability specifies the maximum size of the channel list channel inhibit list synchronous digital I O list and gain list Specifying the Channels in the Channel List Use the ChannelList property to specify the channels in the channel list in the order you want to sample them or output data from them The channels are sampled or output in order from the first entry to the last entry in the channel list Channel numbering is zero based that is the first entry in the channel list is entry 0 the second entry is entry 1 and so on For example if you want to sample channel 4 twice as frequently as channels 5 and 6 you could program the channel list as follows Channel List Entry Channel Descrip
169. want to measure low level signals less than 1 V you are using an A D converter with high resolution gt 12 bits noise is a significant part of the signal or common mode voltage exists To determine if the subsystem supports the differential channel type use the GetSSCaps method specifying the OLSSC_SUP_DIFFERENTIAL capability If this method returns a non zero value the capability is supported To determine how many differential channels are supported by the subsystem use the GetSSCaps method specifying the OLSSC_MAXDICHANS capability e Specify the channel type as differential for each channel using the ChannelType property 101 Chapter 5 102 Notes For pseudo differential analog inputs specify the single ended channel type in this case how you wire these signals determines the configuration This option provides less noise rejection than the differential configuration but twice as many analog input channels For older model boards this setting is jumper selectable and must be specified in the driver configuration dialog The channel list is not used to set the channel type The following subsections describe how to specify channels Specifying a Single Channel The simplest way to acquire data from or output data to a single channel is to specify the channel for a single value operation refer to page 112 for more information on single value operations You can also specify a single channel usin
170. wing capabilities that you can query and or specify for analog and or digital I O operations e Data encoding this page e Resolution page 100 e Channels including channel type channel list channel inhibit list and synchronous digital I O list page 100 e Ranges page 108 e Gains page 109 e Filters page 111 e Data flow modes page 112 e Triggered scan mode page 118 e Clock sources page 122 ay e Trigger sources page 124 e Buffers page 128 and e DMA resources page 135 The following subsections describe these capabilities in more detail Data Encoding For A D and D A subsystems only DTx EZ defines two data encoding types binary and twos complement To determine the data encoding types supported by the subsystem use the GetSSCaps method specifying the capability OLSSC_SUP_BINARY for binary data encoding or OLSSC_SUP_2SCOMP for twos complement data encoding If this method returns a non zero value the capability is supported 99 Chapter 5 Use the Encoding property to specify the data encoding type Resolution Different subsystems may support a number of software programmable resolutions To determine if the subsystem supports software programmable resolution use the GetSSCaps method specifying the capability OLSSC_SUP_SWRESOLUTION If this method returns a non zero value the capability is supported To determine the number of resolution settings supported by the subsyst
171. y that you supply Note The channel list is not used to set the filter for a channel If the subsystem supports more than one filter but does not support a filter per channel the filter specified for channel 0 is used for all channels 111 Chapter 5 Data Flow Modes DTx EZ defines the following data flow modes for A D D A C T DIN and DOUT subsystems e Single value this page and e Continuous post trigger pre trigger and about trigger page 113 The following subsections describe these data flow modes in detail Single Value Operations Single value operations are the simplest to use but offer the least flexibility and efficiency In a single value operation a single data value is read or written at a time The data is returned immediately To determine if the subsystem supports single value operations use the GetSSCaps method specifying the capability OLSSC_SUP_SINGLEVALUE If this method returns a non zero value the capability is supported Specify the operation mode as single value 1 using the DataFlow property For a single value operation you can specify the data encoding resolution channel type range and filter if supported for the specified channel using the specified gain You cannot specify other parameters such as a channel gain list clock source trigger source DMA channel or buffer Single value operations stop automatically when finished you cannot stop a single valu
172. you have selected a board you must specify the subsystem element using the SubSystem property This property returns a subsystem handle called hdass To directly access a subsystem via the DT Open Layers DLLs you need one subsystem handle for each subsystem Alternately you can use the SubSysType and SubSysElement properties at runtime to create a device independent application 94 Software Architecture With these two properties you can set up the application to use a specific subsystem type and element on any selected device for example the first element of type A D In comparison the Subsystem property simply selects the ne subsystem on the board which prevents device independent operation If you are unsure of the subsystems on a device use the EnumSS or the GetDevCaps method EnumSS lists the names and types of elements for all subsystems supported by the specified device GetDevCaps returns the number of elements for a specified subsystem type on a specified device Additionally during runtime use the numSubSystems and SubSystemList properties to list the number of subsystems available on a DT Open Layers board Once you have specified a subsystem element you can configure the subsystem and perform a data acquisition operation as described in the following section Configuring a Subsystem You configure a subsystem by setting its parameters or capabilities For more information on the capabilities you can qu

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