Labview instrument interface

The VI is used to count scattered photons using a National Instruments M622x PC board, and the basic functions of parts to C are described in the text. The detailed meaning of each icon, along with descriptions of the controlhng inputs and outputs, can be seen in LabVIEW by positioning the mouse cursor on the icon. See also the discussion in Chapter III of the use of LabVIEW in interfacing situations. 

Overall, most of the requirements for a process spectrometer/analyzer are straightforward to implement, but they do require attention at the design level. Another important area, which is FTIR-specific, is the user interface and the need to provide for industry standard data communications. Standard software packages do exist for process instrumentation. For prototype development, and even for the front-end interface in a standalone mode of operation, software products, such as Microsoft s Visual Basic and National Instruments LabView, are also important instrumentation development tools. Note that National Instruments also provides important computer-based electronics and hardware that meet most of the computer interfacing, and system control and communications needs for modem instrumentation. 

For the tribological measurements, the radial position of the slider during the tests was halfway between the inner and outer diameters of the disk, and the pivot-to-center distance was adjusted so that the slider skew angle was close to 0°. The disk rotation was started with the slider suspension on the load/unload ramp just off the edge of the disk. The slider was accessed to the test radius. The pressure control and measurement of the frictional displacement were performed with The National Instruments LabView software on a PC with interface cards. Average displacement and peak amplitude were recorded after each pressure decrement/incre-ment (4000 samples at 20 kHz for 200 ms). The pressure inside the tester was varied linearly from ambient (100 kPa) to 15 kPa and back up to ambient over about 3 min in approximately 1-kPa increments. At the end of the test, the slider was translated back to the load/unload ramp before stopping the disk rotation. 

Two different computer interfaces were created for datalogging for both wearable accelerometer subsystem and instrumented platform. The datalogging interfaces were created using both Microsoft Visual Basic and National Instruments LabView Software. All data could be exported as text file for further analysis. Both interfaces provided realtime display on data collected by both subsystems. Fig. 4 shows the interfaces of the subsystems. 

The virtual instrument system based on LabviewS.O for ion analyzer, which has advantages of easy operation and friendly interface, can determine pX, realize real-time displaying and drawing a curve of pX or mV with the change of time t,... 

---