OpenPLC Editor

The OpenPLC Editor is an IEC 61131-3 compliant PLC code editor. It allows you to create, compile and upload your IEC 61131-3 programs to the OpenPLC Runtime. OpenPLC Editor implements all the languages described in the IEC-61131-3 standard: Ladder Logic (LD), Function Block Diagram (FBD), Instruction List (IL), Structured Text (ST), and Sequential Function Chart (SFC).

Basic knowledge of PLC programming can be seen at: http://www.plcs.net/