After a lot of consideration and a push from Lob0426, I decided to start this new thread. This is a project about programming Pi to act as a PLC or a x-axis positioning controller.
So far these controllers are mostly proprietary and in a no way software is open source. So every company makes money because from the moment you attached to them you married them for life.
from the finished product many will benefit:
- Engineers in automation industry
- Hobbyists building home automation, burglar alarms, etc
- Students having hands on automation in a truly open controller.
- many ideas to come if you stay with us
First thinks first. Pi P.L.C must have at least these 4 goals:
1 - Be capable of running Programming language defined by the IEC-61131-3 standard.
2 - be able to communicate real time via Ethernet port to other remote Pi PLCs in a master/slave scenario.
3 - Be able to attach many I/O locally (reed relay, FET transistor out, triac, encoder input) . One idea to use cheep interface boards connected to I2C bus. The encoder input is necessary for positioning system and robotics.
4 - The system must run on a version of real time lynux if we want to capture events on a millisecond or less. Of course a Debian distro is OK if you do not want to be real time.
I have already some ideas because three are people already made a lot and very good open software like http://www.beremiz.org
project (since 2009 I can see no movement to their site but we will try to contact with the developers).
For that we will need some people to write some drivers and to port the application into a real time Linux. It is a lot of work but the final result will give us a lot of satisfaction.
More to come..