Online measurements and control of a laboratory scale DC grid

This paper deals with the development of a complex measurement system for the online control of a laboratory scale DC grid located at "Politehnica" University of Bucharest. This has been achieved by making use of various communication methods among different modules, like DC source, energy meters, server, controllable "load computers", digital oscilloscope and multimeter. PHP and an open source database have been used on the server-side for implementing the external communication, thus reducing the software requirements of the client's computer down to a common web-browser. The internal communication that occurs through various protocols like TCP/IP, ModBUS/TCP and RS232 has been mediated by the database, using LabVIEW Internet Toolkit and the open source .vi library LabSQL. Additionally, the use of an interesting reverse engineering concept helped extracting the communication protocols from the instruments' proprietary applications, thus making possible the full integration of measurement modules into a unique system. The final result is a homogenous measurement system within the laboratory scale DC grid, controllable through a secure, reliable and minimum-requirement online application.