Keithley kpcipio DirectIO CVI free download

File name kpcipio_DirectIO_CVI.pdf

Using the Direct I/O COM API of DriverLINX for the KPCI-PIO24 or KPCI- PIO96 with LabWindows/CVI DriverLINX drivers for digital I/O boards provides two programming interfaces: 1. Service Request API for hardware independence with other KPCI or PIO boards 2. Direct I/O COM API for simple, fast interaction with the registers of the digital I/O hardware COM objects are easily used from Visual Basic or from C++. Use of a COM object from a purely C language such as CVI requires a bit more work to build a proper interface layer into the object. Luckily, LabWindows/CVI provides an automated tool to greatly simplify creation of the interface layer. The resulting function panel file, *.fp, can then be used in conventional ways by CVI to make use of the function calls of the exposed object. Below is a step-by-step guide. The completed project is also available as an example program in the download center. Step 1: In the Tools menu, select 'Create ActiveX Automation Controller...' Step 2: Scroll down the list until you see the Keithley Digital I/O Library. Select it and then click Next. Step 3: Fill in a name for the target .fp file. Any name is fine; I used KPCIDIO (be sure to include the path to the location). Then click the Next button. Step 4: the object will be analyzed by CVI and several output files will be built and placed into the directory location you specified. If any other dialogs present, accept the default values and click Next. When complete, the screen below will appear. Step 5: Now to use the object. From this same session of CVI, the function panel will already be loaded in the Instrument Driver menu drop down. If starting a new session of CVI, first load the fp file. Step 6: Notice the object has two classes: IKPCIPIO and IHardware. IKPCIPIO provides an 8255 interface: a control register and one register for each of three 8-bit digital ports. The IHardware class provides 32-bit register access to the KPCI-PIOxx card. The balance of this application note will refer to the IKPCIPIO class only. Highlight that class as shown below and then click the Select button. Once the IKPCIPIO class has been selected, the member functions are visible. The important ones are New, OpenDevice, CloseDevice, Read and Write. This was just a preview of where we will be going, so hit the Cancel button for now. Step 7: Create a project called testDirectIO. Add the KPCIDIO.fp file to the project. Add also a uir file to the project. Place several buttons onto the user interface as shown below and create all the callback code stubs (a *.c file is created). In the call back for the Open Driver button, the Direct IO API will be initialized and a session opened for the installed board (the device number used in the DriverLINX Configuration Panel will be used). In the Read Port A button, the register corresponding to Port A will be read to obtain the logic 0 or 1 state of the 8-line channel. A value between 0 and 255 will result. In the Exit button, the driv