feature request: Support for 4423

[tdcox]

Please could you consider support for the Pico 4423?

Thank you.

[azonenberg]

I don't have access to one for testing. I do plan to ask Pico for development units of other instrument families, but need to finish the 6000 series driver before I stretch my goodwill with them too far.

Once the 6000 series backend is finished I'm probably going to do some refactoring of the SCPI layer to make it easier to reuse that code for multiple instrument families before adding support for more devices.