Copyright (C) 2018 by Luis Paulo Laus, ------------------------------------------------------------ The tikz-ladder package may be distributed and/or modified under the conditions of the LaTeX Project Public License, either version 1 of this license or (at your option) any later version. The latest version of this license is in: http://www.latex-project.org/lppl.txt and version 1 or later is part of all distributions of LaTeX version 1999/12/01 or later. Version 1.1 2018-02-06 ------------------------------------------------------------ Ladder diagram (LD) is a graphical programming language that has evolved from electrical wiring diagrams for relay control systems used with programmable controllers (PLC) as described in the international standard IEC-61131-3. A LD program enables the programmable controller to test and modify data by means of standardized graphic symbols. These symbols are laid out in networks in a manner similar to a ``rung'' of a relay ladder logic diagram. This library provides TikZ symbols to draw high quality ladder diagrams. All standard and some non-standard symbols are possible, including all kinds of contacts, coils and blocks. I decided to write this package, despite of the fact that there is available another package named `ladder' that also uses TikZ to typeset ladder diagrams, because that package seems to lack support for blocks. The tikz-ladder, on the contrary, supports all features described in IEC-61131-3, namely, blocks (for functions and function blocks), contacts and coils. ------------------------------------------------------------