在Labview平台上的系统集成.ppt

Eneineering Measurement, NAU, Q.S.Ding System integration in LabVIEW Section objectives: Building your own computer-based measurement system AI Acquire Waveform Acquires a specified number of samples at a specified sample rate from a single input channel and returns the acquired data. The AI Acquire Waveform VI performs a timed measurement of a waveform (multiple voltage readings at a specified sampling rate) on a single analog input channel. If an error occurs, a dialog box appears, giving you the option to stop the VI or continue. device is the device number you assigned to the DAQ device during configuration. channel identifies the analog input channel you want to measure. The default input is channel 0. number of samples is the number of single-channel samples the VI acquires before the acquisition completes. The default for this parameter is 1000 samples. sample rate is the requested number of samples per second the VI acquires from the specified channel. The default for this parameter is a rate of 1000 samples/s. high limit is the highest expected level of the signals you want to measure. The default input is 0. If you enter 0, the system uses the highest range supported by hardware. low limit is the lowest expected level of the signals you want to measure. The default input is 0. If you enter 0, the system uses the lowest range supported by hardware. waveform contains scaled analog input data. actual sample period is the actual interval between samples, which is the inverse of the actual sample rate. The actual sample period can differ from the requested sample rate, depending on the capabilities of your hardware. error code description AI error code 5000The configuration file could not be located or opened, or the format of the configuration file is not compatible with the currently installed driver. 5001The analog input channel number is out of range. The start channel number should be greater than or equal to 0, for the maximum of singl