Keysight 34461A DMM Measurement Plugin (Refactor of 34401 DMM example)

[MIpetrov-NI]

• This contribution adheres to CONTRIBUTING.md. (Required)
• Automatically post PR comments with images for G code changes? (Recommended for small changes)

What does this Pull Request accomplish?

High-level description of the changes in this pull request:

• Added a new measurement plugin example for a 3rd party DMM; it's a refactored version of the existing Keysight 34401A DMM Measurement plugin example. I've documented the process (in the readme) for refactoring existing examples to be compatible with different drivers for similar 3rd party instruments. In this instance, I tested implementing the 3446X driver on an Agilent 34461A DMM in InstrumentStudio.

Why should this Pull Request be merged?

Justification for why this contribution should be part of the project:

• This example is meant to contribute to a workflow we can communicate to customers that would make it easier for them to create measurement plugins or use/alter our existing examples to connect their 3rd party devices to our PXI platform.
• Through this workflow, I found that one of our more popular drivers, the 3446X LabVIEW driver, has a bug that has been documented in a KB (and should be fixed rather than communicating a fix to a user), I've linked that KB in this folder's readme.

What testing has been done?

What testing has been done to ensure this submission meets requirements:

• Tested building the LabVIEW project, running the measurement plugin service, and taking measurements in Instrument Studio with no error.
• Tested the implementation on a Keysight 34461A DMM communicating with a windows PC via USB. (laptop & PXI embedded controller)
• Ran the run_tests.vi: the vi crashed after some tests have passed: debugged by verifying VI properties and device connection. Was not able to figure out the reason for this crash, there is no documentation on what to do in this event.
• Have not tested the TestStand implementation.