Configuring Polynomial Coefficients of Hardware Calibration Files in VeriStand

Updated Aug 14, 2019

Reported In

Software

  • VeriStand

Issue Details

How can I define hardware calibration coefficients in VeriStand and deploy them to my target(s)?

Solution

VeriStand supports polynomial hardware calibrations with up to ten coefficients in the following format:
In VeriStand, these hardware calibration coefficients are stored in a .nivscf file, which is included in the project.
 
Figure 1 - Calibration file in the Project Explorer
 
Upon deployment of the system, the .nivscf file deploys through the gateway to the target(s) defined in the .nivssdf file. The contents of the .nivscf file follow the XML Schema definition language. There are three ways in which you can modify calibration coefficients as defined in the .nivscf file: 
  • Channel Calibration Tool
The Chanel Calibration tool is a workspace tool you can launch from the Project Explorer or the Workspace window. This tool allows you to push calibration coefficients to particular hardware channels during run-time.
 
  1. To launch the tool from either the Project Explorer or Workspace window, select Tools » Channel Calibration. Upon launch, a window for hardware channel selection will appear.
Figure 2 - Hardware channel selection for calibration in the Channel Calibration Manager
 
2. After selecting a particular hardware channel, you can then select Next to enter user information and then Next again to define your  calibration coefficients.
 
Figure 3 - Define calibration coefficients for a particular channel
 
  • VeriStand API

    VeriStand ships with both a LabVIEW and .NET API for controlling VeriStand from an external environment. To apply a polynomial calibration to a hardware channel from LabVIEW, use the Set Calibration VI. The list of calibration-oriented VIs is provided in the VeriStand Help: Calibration VIs.
Note: For each LabVIEW VI, there is a corresponding .NET method. These methods are further outlined in the VeriStand Help: NationalInstruments.VeriStand.ClientAPI Namespace.
 
  • Manually Modify the Calibration XML

    The .nivscf file is composed in XML. You can modify the XML of this file manually in a text editor, however, this approach is not recommended for typical use cases. 

Additional Information

  • The Channel Calibration tool also provides a set of calibration management utilities for tracking previous calibrations.

Figure 4 - Channel calibration history with user tracking
 
  • For additional information about the XML Schema definition language, please refer to Related Links.