NI-DAQmx Virtual Channel Calibration
Print
The National Instruments Getting Started with NI-DAQmx Series is aimed at helping you learn NI-DAQmx programming fundamentals. Through video and text tutorials, this series will take you from verifying your device's operation in Measurement & Automation Explorer (MAX) to programming data acquisition applications using LabVIEW. It is intended for both the beginner who wants to learn how to use the DAQ Assistant, as well as the experienced user who wishes to take advantage of advanced NI-DAQmx functionality.
Engineers and scientists developing data acquisition applications can now use the new Channel Calibration Wizard to quickly calibrate the entire measurement path for a channel – from the sensor through to the measurement device – and then apply the resulting correction to every measurement taken on that channel. Engineers calibrate the measurement by applying an external calibration reference and the measured value is compared to the actual value. This calibration supplements internal device calibration by also accounting for errors introduced by the sensor, signal conditioning, and cabling. Many existing drivers only offer device calibration and neglect the inaccuracies introduced through the rest of the measurement path.
Developers can calibrate analog input virtual channels using the Channel Calibration Wizard from the DAQ Assistant.
Follow these instructions, also included in the NI-DAQmx Help, to complete calibration of a virtual channel.
1. Select an existing task or global channel or create a new task or global channel.
2. Click the Calibration tab in the DAQ Assistant.
Figure 1. Calibrate analog input virtual channels with NI-DAQmx
3. Select one or more virtual channels from the Channel List. You must select only one type of virtual channel. If you select virtual channels of different measurement types, the Calibrate button is disabled.
4. Click Calibrate. The Channel Calibration Wizard launches.
5. Complete the screens to calibrate the selected virtual channel. You can calibrate as many data points as needed to produce a calibration table. The Channel Calibration Wizard stores a set of calibration properties for each virtual channel you calibrate. Select Properties in the Calibration tab of the DAQ Assistant to view calibration history, verify the calibration, recalibrate the selected virtual channel(s), and generate a calibration report.
6. After calibrating the virtual channel, click Enable Calibration to enable or disable the calibration. If Enable Calibration is disabled, the calibration is saved but not applied to the selected virtual channels. To delete a calibration, select one or more virtual channels in the Channel List and click Delete Calibration.
Related Links:
Virtual Channel Calibration Examples
Reader Comments | Submit a comment »
Legal
This tutorial (this "tutorial") was developed by National Instruments ("NI"). Although technical support of this tutorial may be made available by National Instruments, the content in this tutorial may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this content with each new revision of related products and drivers. THIS TUTORIAL IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).