DMM comparison, GPIB code running on DE1-SOC

7V test
TC 2001-20 : +0.458 ppm/K
TC 2002-4 : <0.1ppm/K
TC 2002-6 : <0.1ppm/K


Result CSV-data from HP 3458A

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 :)