Automate LabVIEW from Python
Project description
autolv - Interact with LabVIEW VIs from Python
The only export from autolv is App that opens an ActiveX connection to LabVIEW through its VI Server. With a reference to LabVIEW it is then possible to open an ActiveX connection to a specific VI. The primary use case for this library is to set control values on the VI front panel from Python, run the VI, and read the control values back into Python.
Installation
pip install autolv
Example usage
Suppose the VI name is 'test.vi' and has a single Numeric control with the name (label) 'input' and a single Numeric indicator with the name 'output'. The VI implements 2*'input' -> 'output'
>>> import autolv
>>> lv = autolv.App()
>>> vi = lv.get_VI('test.vi')
>>> vi.input = 2.0
>>> vi.run()
>>> vi.output
4.0
Now move the 'input and 'output' Numeric controls into a Cluster called 'data'.
>>> vi = lv.get_VI('test.vi')
>>> vi.data.input = 3.0
>>> vi.run()
>>> vi.data.output
6.0
It's possible to get an error code explanation. Suppose a VI attempts to create an invalid DAQmx channel.
>>> vi = lv.get_VI('error.vi')
>>> vi.DAQmx = "PXI1Slot2"
>>> vi.run()
>>> vi['error out'].code.value
-201237
>>> lv.explain_error(_)
'Physical channel name specified is invalid...'
Notes
- LabVIEW's Cluster is supported, but not as nested clusters.
- LV Controls have a Label attribute. ActiveX calls this Label 'name' and this is the only mechanism for set/get a Control. So, the Label must be unique among the front panel controls.
- As a best practice, it is recommended to set the Label to a valid Python identifier. This increases productivity when using dot-access in an interactive session such as IPython.
- If your machine has multiple LabVIEW versions, launch the desired version first before interacting with it in Python.
- LV's 'Time Stamp' comes across ActiveX as naive and represented in Python as datetime.datetime.
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.