От: | DarkGray | http://blog.metatech.ru/post/ogni-razrabotki.aspx | |
Дата: | 15.06.12 23:15 | ||
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IEC 61131-3 is the third part (of 8) of the open international standard IEC 61131 for programmable logic controllers, and was first published in December 1993 by the IEC. The current (second) edition was published in 2003.
Part 3 of IEC 61131 deals with programming languages and defines two graphical and two textual PLC programming language standards:
Ladder diagram (LD), graphical
Function block diagram (FBD), graphical
Structured text (ST), textual
Instruction list (IL), textual
Sequential function chart (SFC), has elements to organize programs for sequential and parallel control processing.
Ladder logic is a programming language that represents a program by a graphical diagram based on the circuit diagrams of relay logic hardware. It is primarily used to develop software for programmable logic controllers (PLCs) used in industrial control applications. The name is based on the observation that programs in this language resemble ladders, with two vertical rails and a series of horizontal rungs between them.