Chip 1997 September

home *** CD-ROM | disk | FTP | other *** search

/ Chip 1997 September / CHIP_CD_1997_09_PL.iso / software / testsoft / labwind / demo.3 / main / samples.doc < prev next >

Wrap

Text File | 1996-08-02 | 35.5 KB | 795 lines

LabWindows/CVI, Version 4.0.1 Sample Programs Documentation File (c) Copyright 1994-1996 National Instruments Corporation. All rights reserved. Product and company names listed are trademarks or trade names of their respective companies. LabWindows/CVI comes with many sample programs to help you learn and understand key concepts of LabWindows/CVI. You can use these programs as starting points for your applications. The following brief description of the sample programs matches the directory structure of the samples sub-directory in the main CVI directory. If you are viewing this file with the Windows Notepad application, you can use the Search option to search for specific keywords or functions you want to learn about. ANALYSIS (Advanced Analysis Only) --------------------------------- convolve.prj - demonstrates the Convolve and Deconvolve functions in the Advanced Analysis library. Two sets of controls specify the number of points, cycles, wave type, and amount of noise of of each of the two input signals. The program displays the two signals on the upper two graphs and the convolve and deconvolve of the signals on the lower graphs. correlat.prj - demonstrates the Correlation function in the Advanced Analysis library. Two sets of controls specify the number of points, cycles, wave type, and amount of noise of of each of the two input signals. The program displays the two signals on the upper two graphs and the correlation on the lower graph. interp.prj - demonstrates the use of the PolyInterp, RatInterp and SpInterp functions in the Advanced Analysis Library. The user generates a series of points to use as the known values in the array. The points can be generated randomly or entered graphically with the graph cursor. The interpolated points and error range is graphically displayed over the series of points. mode.prj - illustrates using of the Histogram and Mode functions in the Analysis libraries. The mode value is defined as the value that most often occurs in a given set of samples. nonlnfit.prj - illustrates how to use the Nonlinear Fit function in the Advanced Analysis Library. The user specifies a particular data function to generate data from and a function to fit the data to. Gaussian noise can be added to the generated data to simulate actual acquired data. A nonlinear fit is then generated and plotted and the parameters of the best fit are also displayed. peak_est.prj - use the AutoPowerSpectrum and PowerFrequencyEstimate functions in the Advanced Analysis library. The top graph displays an input signal in the time domain and the bottom graph displays the power spectrum of the filtered input signal. Using the graph cursor the peak frequency and its power can be calculated at different displayed frequency peaks. phasedif.prj - demonstrate the calculatation of the phase difference between two sine waves. The number of points, cycles, and phase of two input sine waves are configurable. pulse.prj - demonstrates the PulseParam function in the Advanced Analysis library. The pulse waveform can be generated randomly or manually. Data returned from the Pulse function is displayed on the main panel. windowng.prj - illustrates the different windowing functions available in the Advanced Analysis library. Two combined sinusoidal waveforms, one of which has an amplitude greater by a factor of 1000, are displayed in the frequency domain on either a linear or log scale. Two different windowing functions can be applied in parallel to compare the different effects in the frequency domain. APPS ---- atedemo.prj - illustrates how an automated test sequence can be implemented with LabWindows/CVI. This program will ask the user to input some test characteristics and then will run a test sequence while displaying a test log on the screen. freqresp.prj - generates a frequency response for a Butterworth bandpass digital filter and performs curve fitting on the plotted points. This example illustrates the use of basic CVI User Interface controls such as knobs, graphs and numeric displays. This program assumes that the CVI Advanced Analysis library is installed. iconedit.prj - illustrates how CVI can be used to create other applications not related to test and measurement. This particular program implements a simple bitmap editor which can be used to create Windows icons. life.prj - A simulation of life. Place cells on the canvas and see what evolves. Based on a simple set of rules, new cells will grow and old ones will die out. This program illustrates the use of batch drawing on the canvas control. lissa.prj - is an interesting and fun application program that shows how to use some basic controls in a Graphical User Interface built with LabWindows/CVI. This application displays various Lissajous figures obtained by plotting two different periodic functions opposite to each other on a graph. Important features presented here are the usage of signal generation functions and the ability to save and load the current control settings. lockout.prj - illustrates how a CVI panel window can be configured so it cannot be switched from or closed by a user. This application disables the Windows task switching feature (accessed with the Alt-Tab keys) by using the DisableTaskSwitching function, maximizes the panel and removes the minimize/maximize icons of the CVI window. mandel.prj - interactively displays Mandelbrot images (fractals) with the intensity plot function. New and interesting fractal regions can be explored by changing the plotting coordinates with the graph cursors. It allows users to experiment with the different interpolation options and save favorite plot settings. marquee.prj - is a sample program that prints a moving banner on the screen. The GUI for this application is built programmatically with functions such as NewCtrl and NewMenu. The speed of the moving banner is modified by changing the rate at which the periodic idle events occur. scopedem.prj - is a sample program that simulates an oscilloscope with two channels and variable settings for gain and timebase. A waveform can be saved to disk and then viewed with the notepad application. An instrument driver provides additional functions needed by this program. The instrument driver is located in the instr directory and is named scope.fp. sigproc.prj - is an application program that generates a signal and then conditions it with various filters. This program uses the CVI Advanced Analysis library. spectrum.prj - is a frequency analysis program designed to perform fourier analysis on either a simulated analog signal or an analog signal acquired through a DAQ board. The sampled signal is continuously displayed in an upper graph while the simulation or data acquisition is enabled. The user may view either the power spectrum of the signal or the windowed and filtered time waveform on a lower graph. The signal may be filtered with either FIR or IIR lowpass, highpass, bandpass, or bandstop filters. The filter and data aquisition features can also be customized. This program assumes that the CVI Advanced Analysis library is installed. tempsys.prj - is a simple temperature monitor program. This application generates random temperature readings and displays them on a strip chart in continuous mode. Statistical processing is done on the random samples and a histogram is then displayed in a graph control with vertical bar display. update.prj - is an application program that simulates an oscilloscope display to illustrate how the update rate of a plot function is related to the length of the buffer being displayed and the type of chart used. The waveforms can be displayed on a graph control with or without smooth update and on a strip chart control with sweep, continuous or block updating. workshop.prj - is an application that allows the user to modify an image in PCX format with the Windows Paintbrush application and then re- display it on a CVI panel. The program makes use of the LaunchExecutable function to run the Paintbrush application. The program also demonstrates the usage of SystemHelp function to display Windows-type help for a CVI application. uirview\uirview.prj - is an application that allows the user to display and snapshot UIR file panels. The user can change some panel attributes dynamically, copy an image of the panel to the clipboard or save the bitmap image to a BMP file. UIR callbacks are not necessary to load a user UIR file. CUSTCTRL -------- A set of sample programs is provided to demonstrate the use of the ECHO control instrument drivers in the toolslib directory, such as the password control and the DAQ controls. See toolslib.doc for the location of these sample programs and for a description of each instrument driver. DAQ --- Note: The following programs are not part of the LabWindows/CVI software distribution. These programs will be installed with the latest NI-DAQ software for PC compatibles. If you do not have a daq sub- directory in the samples directory then you must install the NI-DAQ software first to access these programs. The NI-DAQ software is available free of charge from National Instruments. aiaoxmpl.prj - shows how single channel analog input/output is done. It uses the AI_Read and AI_Write functions. daq_op.prj - illustrates a single channel synchronous data acquisition. It uses the DAQ_Op function to acquire the binary data and the DAQ_VScale function to scale the binary data to voltage units. daqstart.prj - shows how a single channel asynchronous data acquisition is done. It uses the DAQ_Start function to start the acquisition and then monitors the acquisition progress from a main callback routine with the DAQ_Check function. dblbuffer.prj - demonstrates a double buffered data acquisition. A pop- up panel is used to configure settings for the DAQ board. digital.prj - is a simple digital I/O example. It uses the DIG_In_Line, DIG_Out_Line and also the port write & read functions to turn on or off LED controls on the user interface. The ports are configured as output or input with the DIG_Prt_Config function. dqdbxmpl.prj - shows a double buffered data acquisition to disk. This project does not have a user interface file and it builds the GUI programmatically. eventcnt.prj - is a counter and timer example. This example uses the counters on a data acquisition board to count signal edges. A main callback routine is used to read the accumulated events periodically with the CTR_EvRead function. freqmeas.prj - demonstrates how the frequency of an input analog signal can be measured with the CTR_ functions. This example makes use of most of the CTR_ functions available in the Data Acquisition library. ictr.prj - shows how to use the interval counter functions (ICTR_ calls). scan_op.prj - is an example of a two channel synchronous data acquisition. It uses the Scan_Op function to read data from two channels and then the Scan_Demux function to re-order the data for graphical presentation. scxiread.prj - performs a single SCXI channel analog input. This example shows the usage of basic SCXI functions. scxiscan.prj - illustrates SCXI channel scanning in multiplexed or parallel mode. This can be used with multiple modules and multiple channel gains. scxitemp.prj - reads an analog input signal from a thermocouple, converts the voltage to temperature using an instrument driver and displays the running temperature on a strip chart. wfmout.prj - is an example of how to use the WFM_Op function to generate a waveform asynchronously. Note: The following data acquisition programs will be available in the NI-DAQ version 4.6.1 and later releases. To find out what version of NI-DAQ you have you can run the Get_NI_DAQ_Version function in the Data Acquisition library. bufgpctr.c - illustrates the use of dual dma channels to acquire data using buffered GPCTR functions on E Series boards. eqvtimsm.c - illustrates the Equivalent Time Sampling technique, which allows you to sample a repetitive input signal at an effective rate of 20MHz. rtchgfly.c - illustrates a method for acquiring an array of voltage data asynchronously, using general purpose counters for timing. scxi_vrd.prj - uses the SCXI Analog Input Instrument driver to acquire a single analog input voltage from an SCXI module. It also uses the channel string input to define the chassis, module, and channels used. scxichrt.prj - uses the SCXI Analog Input Instrument driver to acquire a voltage from multiple SCXI channels. It uses the channel string input to define the chassis, module, and channels used. scxicont.prj - uses the SCXI Analog Input Instrument driver to acquire a continuous voltage from multiple SCXI channels. It uses the channel string input to define the chassis, module, and channels used. This example illustrates double buffering in conjunction with SCXI functions. scxi_op.prj - uses the SCXI Analog Input Instrument driver to acquire a voltage waveform from multiple SCXI channels. It uses the channel string input to define the chassis, module, and channels used. scxi_tc.prj- uses the SCXI Analog Input Instrument driver to acquire a temperature reading from multiple SCXI channels. It uses the channel string input to define the chassis, module, and channels and a temperature conversion instrument driver to convert voltages to the correct temperature values. scxitrig.prj - is identical to scxi_op.prj with the option of digital triggering enabled. use3dma.prj - illustrates the use of the DAQ double buffered analog input functions for acquiring voltage data continuously. DDE --- EXCEL ddedemo.prj - is an example of how to use the Dynamic Data Exchange (DDE) library functions to communicate with another Windows application. The program passes data between Microsoft Excel and LabWindows/CVI via a warm DDE link. If you have Excel, launch it before you run this example and load in the LWCVI.XLS file found in the same directory as the project. ddeexcel.prj - uses the DDE functions to execute commands in a Microsoft Excel application. The commands illustrated are: OPEN sheet, CLOSE sheet, RUN macro, and QUIT Excel. These commands are executed from LabWindows/CVI with the ClientDDEExecute function. MISC prgmndde.prj - is an example of a DDE connection with the Windows Program Manager application. The program acts as a DDE client and, once connected to the Program Manager which acts as a server, it allows the user to create a new program group and items directly from LabWindows/CVI. This program uses the ClientDDEExecute function to send commands to the Windows Program Manager. srvclt.prj - illustrates client/server communication with the DDE functions. The program spawns two other programs, a server and a client, that communicate via a hot DDE link. The server, in this case, generates some waveform data which is then passed to the client to be plotted on a graph. The client can read data and execute various commands from the server. An important note about the Windows DDE limitation is included as a comment at the top of the server.c file. VBASIC cvidde.prj - demonstrates the use of DDE functions to communicate with a program written in Visual Basic. This CVI program implements both a client and a server which communicate with a Visual Basic server and client, respectively. This program requires that a Visual Basic application is running in the background. The necessary Visual Basic files are included in the same directory with the CVI program. DLL (Windows 95 and Windows NT Only) ------------------------------------ CVITEXT cvitext.prj - creates a simple dll that draws text on a CVI panel using SDK functions. useit.prj - demonstrates the calling of the cvitext.dll by using an import library. You must create the dll and import library first by opening cvitext.prj and selecting "Create Dynamic Link Library" in the Build menu. SIMPLE In each of five subdirectories are the files necessary to build a dll in cvi or one of the four external compilers (msvc, borland, watcom, and symantec), and a cvi project (simple.prj) which uses the dll as described below. mydll.prj - creates a dll and import library which has three different exported functions. One function illustrates how a dll can be called to display and operate a UIR file independent of the calling program. Two other functions illustrate the ability to export a function as either stdcall or cdecl. simple.prj - demonstrates the calling of mydllÆs exported functions. You must create the dll and import library first by opening mydll.prj and selecting "Create Dynamic Link Library" in the Build menu. DLL (Windows 3.1 Only) ---------------------- 32BITDLL tstdll32.prj - shows how a 32-bit DLL can be imported in LabWindows/CVI. The glue code necessary for this DLL differs from the glue code for a 16-bit DLL and the differences are pointed out in the glue code file (dll32glu.c). The DLL was created with the Watcom C 32-bit compiler. At this time, the only 32-bit DLLs supported in LabWindows/CVI are the ones created with the Watcom compiler. CALLBACK useit.prj - This sample illustrates: 1. Calling CVI functions from a DLL (callbacks) 2. Converting pointers received from the DLL - pointers that point to CVI data - pointers that point to DLL data 3. Use of a pth file because the DLL filename is not the same as the glue code filename. CVITEXT useit.prj - This dll is an example of how to draw text onto a CVI panel from a DLL. DPMILOCK dpmilock.prj - illustrates the use of DPMI to lock a buffer in memory. One of the restrictions for a 16-bit DLL to work with LabWindows/CVI is that a buffer should not be locked in memory with the GlobalPageLock function available in the Windows SDK library. The function will fail on buffers already allocated with the malloc function in LW/CVI. Any DLL using GlobalPageLock function should be modified to use DPMI calls. The usage of DPMILock and DPMIUnlock functions is shown in this sample program. The source code for these functions is included in the DLL (dpmilock.dll) which is not shown in the project list, but is loaded through its associated glue code (dpmiglue.obj) and the dpmiglue.pth file. You can use these functions and the glue code to replace the GlobalPageLock function in your own DLL. FLOATDLL fltstapp.prj - shows the modifications needed to be made to a DLL that performs floating-point operations. If a DLL is compiled with the /Fpi or /Fpc switches, then the DLL uses the WIN87EM.DLL floating-point emulator. LabWindows/CVI does not use this emulator so the status of the co-processor registers are lost when the DLL performs floating-point operations. This example shows how the DLL should perform the floating- point operations in order to be able to work in CVI. The DLL is loaded directly by being listed in the project list. The source code for the DLL is located in the same directory as the other project files. INTRPTR intrptr.prj is an example of how to modify a 32 bit memory buffer allocated by a CVI program from an interrupt routine in a 16 bit dll. The program uses the Alloc16BitAlias() function to allocate a selector which can access CVI's 32 bit memory area during an interrupt service routine. SIMPLE simple.prj - This dll is an example of how to create a simple DLL which will popup a Windows Message Box. WINMSG winmsg.prj - is an example of communication between LabWindows/CVI and an interrupt routine in a 16-bit DLL. The program installs a callback routine, with the RegisterWinMsgCallback function, which will be entered when a Windows message is passed back to CVI from the DLL. The DLL will trap a keyboard interrupt and then post the message to LabWindows/CVI. EASYIO ------ This directory contains sample programs that use the Easy I/O for DAQ Library. ai_acq.prj - performs a timed analog acquisition using AIAcquireWaveforms() and plot the results to a graph. ai_async.prj - performs an asynchronous timed analog acquisition using AIStartAcquisition(), AICheckAcquisition(), AIReadAcquisition(), and AIClearAcquisition(). If you configure a trigger mode using the "Triggering" button on the user interface, AIAcquireTriggeredWaveforms() is called repetitively. ai_cmd.prj - allows you to embed commands into the channel string to set the upper and lower limits on individual channels as well as the inter- channel sample rate. See the function panel help for the Channel String parameter of AISampleChannels() for details. ai_ets.prj - demonstrates an acquisition using the Equivalent Time Sampling technique. ETS can be used on an E-Series DAQ device to achieve an effective acquisition rate of up to 20 MHz. See the functiona panel help for the Trigger Type parameter of AIAcquireTriggeredWaveforms() for details. The graph shows both the ETS waveform and the "internal" waveform that was sampled using internal timing so that you can compare them. ai_samp.prj - reads analog input channels using AISampleChannels() and plots the results to a strip chart. ao_wave.prj - performs an asynchronous timed analog waveform generation using OGenerateWaveforms() and AOClearWaveforms(). A waveform editor is provided on the panel for customizing the waveform. This program also incorporates the functionality of ai_async.prj. You can tie the analog output channel to the analog input channel in order to acquire and view the waveform that is generated. ctr_evt.prj - uses a DAQ-STC or Am9513 counter to count TTL edges of the signal on the specified counter's SOURCE pin or the number of cycles of a specified internal timebase signal. When the internal timebase is used, CounterEventOrTimeConfig() in conjunction with CounterStart() and CounterRead() can be used to make more precise timing measurements than with the Timer() function. If you select "Use Counter Source" from the Source/Timebase control, you must supply a TTL signal to the SOURCE pin of this counter. ai_log.prj - logs data to disk while asynchronously acquiring data. Data can be stored in ASCII format for importing into a spreadsheet or stored as binary to optimize for speed. ctr_freq.prj - uses a DAQ-STC or Am9513 counter to measure the frequency of a TTL signal on the specified counter's SOURCE pin by counting rising edges of the signal during a specified period of time. ctr_perd.prj - configures a DAQ-STC or Am9513 counter to measure the pulse width or period of a TTL signal connected to its GATE pin. The measurement is done by counting the number of cycles of the specified timebase between the appropriate starting and ending events. The higher the timebase frequency, the greater the measurement accuracy will be. This example incorporates the functionality of ctr_puls.c as a pulse generator so you can tie the OUT pin of the counter that is generating pulses to the GATE of the counter performing pulse measurement. ctr_puls.prj - configures a DAQ-STC or Am9513 counter to generate a continuous TTL pulse train or a delayed TTL pulse on its OUT pin. This project also incorporates ai_async.c and ai_async.uir so that you can monitor the pulses on an analog input channel. ctri_pls.prj - This module shows you how to use an 8253 counter on the Lab boards, SCXI-1200, DAQPad-1200, PC-LPM-16, or the DAQCard-700 to generate square waves and single pulses. There are some external connections that need to be made on your DAQ device for proper operation of this example. The connections are detailed in the Instructions section of ctri_pls.uir. SIMPLE This directory contains simple sample programs that use the Easy I/O for DAQ Library. The goal of these projects is to introduce DAQ concepts using a minimal amount of source code. ai^acq.prj - performs a timed analog acquisition using AIAcquireWaveforms() and plot the results to a graph. ai^async.prj - performs an asynchronous timed analog acquisition using AIStartAcquisition(), AICheckAcquisition(), AIReadAcquisition(), and AIClearAcquisition(). ai^log.prj - logs data to disk while asynchronously acquiring data. Data can be stored in ASCII format for importing into a spreadsheet or stored as binary to optimize for speed. ai^samp.prj - reads analog input channels using AISampleChannels() and plots the results to a strip chart. ai^trig.prj - calls AIAcquireTriggeredWaveforms() repetitively and displays triggered data on a graph. EXTCOMP (Windows 95 and Windows NT Only) -------------------------------------- UIRCBCKS In each of four directories are the files necessary to build an executable in one of the supported external compilers which makes use of the cvi run-time dll and a .uir file. FILEIO ------ fileio.prj - demonstrates a basic file I/O operation. This sample program generates a waveform and stores the data to a file in either ASCII or binary format. Another subroutine reads the file and re- displays the waveform. The program makes use of the ArrayToFile and FileToArray functions to write and read from the file. Note: The usage of the FmtFile and ScanFile functions along with other format and scan functions is documented with numerous examples in the "Formatting and I/O Library" section of the Standard Libraries Reference Manual. GPIB ---- gpibrw.prj - implements a simple GPIB application. This program will send commands to a selected GPIB address and receive data from the device at that address. If no GPIB device is connected you can select to send commands to the GPIB controller board to verify its operation. This program makes use of GPIB device functions such as ibwrt and ibrd and board functions such as ibic. PRINTING -------- hires.prj - is a sample program that makes use of the PrintGraphHiRes function to print a strip chart in high resolution format. The program will print two graphs on the default printer showing how the printout looks before and after using the PrintGraphHiRes function. This program uses the High Resolution Printing instrument driver which is provided in the toolslib\printing directory. RS232 ----- serial.prj - illustrates a typical communication with a RS-232 device. This program will send commands to a serial device and receive data through the serial port. The port to be used in communication can be configured for speed, handshake and other parameters. Some of the functions used are OpenComConfig, ComWrtByte and ComRdByte to open the serial port, write and read from it, respectively. SOUND ----- sndplay.prj - a demonstration of how to play .WAV files in MS Windows. The program displays a listing of .WAV files in a directory and allows you to play them using your sound card or PC speaker (it is assumed that you have the proper drivers installed). In Windows 3.1, this program uses the playsnd.fp instrument from the cvi\toolslib\sound directory. In Windows 95 and Windows NT, this program uses the Windows SDK multimedia library directly to achieve the same result. TCP --- tcpserv.prj - demonstrates how to use functions in the TCP library to set up TCP server to which a client can connect via TCP protocol. The program implements a talk application which allows two users connected via TCP to communicate back and forth. The server program can both receive and send data to the client. The program makes use of the RegisterTCPServer function to activate the TCP server and ServerTCPWrite to write data to the client. tcpclnt.prj - demonstrates a TCP client implementation. The client connects to the server started by the tcpserv.prj program, accepts commands from the user interface and sends them to the server via TCP. The client will also receive any data coming from the server. This example makes use of functions such as ConnectToTCPServer, ClientTCPWrite and ClientTCPRead to communicate with the server. USERINT ------- 2yaxis.prj - shows how to use left and right Y axes on the same graph and how graph cursors can be assigned to the two axes. autostrp.prj - demonstrates how you can autoscale the Y-axis on a strip chart. The UI library supports autoscaling only on graphs, not on strip charts. This program simulates autoscaling by storing the data before sending it to the chart, and then using SetAxisRange to modify the Y-axis as needed. build.prj - is a simple program that generates a random number and displays it on a numeric indicator. The GUI for this application is created programmatically. callback.prj - shows the use of the callback programming model in CVI as opposed to the event-loop model. This program generates a set of random numbers and plots them on a graph control with the PlotY function. The user interface events are processed by callback functions associated with a control. canvas.prj - demonstrates drawing on a Canvas control, including objects such as arcs, rectangles, polygons, lines, ovals and bitmaps. canvsbmk.prj - shows the increase in speed you can achieve by using a canvas control control instead of a graph control for drawing objects such as arcs, rectangles, polygons, lines, ovals and bitmaps. chart.prj - demonstrates the use of a strip chart control. The program plots three randomly generated traces on the same chart which is continuously updated by the callback function of a timer control. clipbord.prj - demonstrates how to use the clipboard functions to transfer images and text to and from the system clipboard. cursors.prj - demonstrates the use of cursors on a graph. This program allows the user to move a set of different style cursors, obtain their x-y coordinates and zoom in on a region delimited by the cursors. Functions such as GetGraphCursor, SetGraphCursor and SetAxisRange are used. drawpad.prj - shows how to use a canvas control as a drawing port or scratch pad for the mouse. events.prj - shows how to recognize many of the low-level events and event-related information that LabWindows/CVI passes from the user interface to the user program. This program uses control and panel functions to process the events as they pass through the hierarchy of callback functions. Event specific information such as the x-y coordinate of a mouse click is displayed in a text box control. getusrev.prj - shows the event loop programming model. Although the callback function model is much more flexible and easy to use, the event loop model can be used to advantage in certain applications (such as modal dialog boxes). LabWindows for DOS programs use the event loop model exclusively. Thus, programs translated from LW/DOS use the event loop model unless you restructure them to use the callback model. graphs.prj - is an application program that makes use of most of the plot functions, such as PlotY, PlotLine and PlotWaveform, to display various lines and shapes on a graph control. Colors can be interactively changed with the use of a color numeric control. imagedit.prj - this is a very simple program which modifies the colors of an existing image. It loads an image loading them into a picture ring and then makes use of the GetImageBits and SetImageBits functions. intgraph.prj - this shows the different ways in which intensity plots can be used in a graph. It allows you to experiment with the different interpolation options as you plot a semi-random block of data. io.prj - is a very simple program that makes use of the standard I/O window through C calls such as printf and scanf. keyfiltr.prj - demonstrates how to alter a control's behavior by responding to keypress events. The program displays a string control and modifies how it handles keyboard input according to options selected using checkboxes. listbox.prj - demonstrates how to add and delete items from a list box control with functions such as InsertListItem and DeleteListItem. listdelx.prj - shows how to add items of different colors to a list box control. Appropriate escape characters in a string can control its background and foreground colors as well as the positioning in the list box. A list of the available escape sequences can be found in the help for the Item Label parameter in the InsertListItem function panel. menus.prj - shows how menu bars can be created and used in a CVI application. The pull-down menus have cascade options and hot keys associated with them. Menu callback functions are used to process the menu selections. A text box control is used to display a help note. moustate.prj - show how to use the GetGlobalMouseState and GetRelativeMouseState functions. These functions can be used to determine the current position of the mouse or the current state of the mouse buttons or SHIFT and CTRL keys on the keyboard. panels.prj - demonstrates how to load multiple panels and sub-panels. The sub-panels are windows owned by another panel. picture.prj - demonstrates how picture controls can be used to enhance a user interface. The user interface displays two PCX images imported into two picture controls. The two images are placed on top of each other and, when a left click event occurs on the picture control, a callback function is called to hide the current image and display the other. piedemo.prj - demonstrates the use of a canvas control to draw a pie chart using an instrument driver. popups.prj - shows most of the popup panels that can be used in LabWindows/CVI. Functions such as FileSelectPopup and MessagePopup are used in a short user tutorial. textbox.prj - demonstrates how a text box control can be used in CVI to display help and status information. Various actions that could be performed on a text box are shown, such as how to add a new line of text, how to insert and how to delete text. timeaxis.prj - demonstrates the use of arbitrary axis labels for a graph. Notice that X-axis labels are labeled as time increments instead of integer values. For this example, each point on the graph represents 1 second. Moving the graph cursor on the graph with the mouse will update the time value displayed in the Graph Details area of the panel. timerctl.prj - demonstrates how a timer control can be used to continuously update a strip chart. The strip chart is updated even when other controls are operated or when the strip chart is obscured by a popup panel. UTILITY ------- physdemo.prj - is a sample program which shows how to access physical memory from LabWindows/CVI. This program makes use of the ReadFromPhysicalMemory and WriteToPhysicalMemory functions, found in the Utility library, to read and write to an absolute address in memory (in this case the monochrome display memory). WIN32 (Windows 95 and Windows NT Only) -------------------------------------- oneinst.prj - demonstrates how to use a new function available in the Windows 95 and NT versions of CVI to insure that only one instance of your application will be running on your computer at a time.