Elettrolinux

ClassicLadder is a type of programming language originally implemented on industrial PLC's (it's called LadderProgramming). It is based on the concept of relay contacts and coils, and can be used to construct logic checks and functions in a manner that is familiar to many systems integrators. But ClassicLadder is, also, a project to have a free ladder language in C. Generally, you find this type of language on PLC to make the programs; free ladder & sequential (grafcet) languages as used on many PLC for programming automation process. Ladder language allows to realize programs on PLC in an electric way. Modbus protocol for SCADA cnx and remote I/O modules. The following elements are available in the ladder:

• Booleans elements;
• Rising/Falling edges;
• Timers;
• Monostables, counters and compare of arithmetic expressions;
• ...and many other!

• Add a rung after the current rung;
• Insert a rung before the current rung;
• Modify the current rung;
• Delete the current rung.

It has support to the real time; RTLinux, RTAI, Xenomai and Comedi project.