Test FX792 (3458STD) + SL935 (8508A)

Reference levels:

Result CSV-data

Workflow:

* RPI accesses DMMs via GPIB and reads data.
* Data is formatted by python script into DSV string and written/append to file on FTP
* DSV-file is visible publicly on https://xdevs.com/datashort/
* Page http://xdevs.com/datalog_mm/ runs D3.js javascript library to read DSV file test.log to input data
* D3.js plots SVG graph online :)