I want a reliable open source web based SCADA software which is platform independent, support modbus tcp communication protocol, and has a PID module or can be implemented.
I found some software programs that match my criteria but I can't choose the best match
1- Mango automation "but I found that it is not free for the commercial use" http://infiniteautomation.com/
2- rapid scada http://rapidscada.org/
3- Integraxor http://www.integraxor.com/