ClassicLadder是一个开放源码的电路仿真程序，使您能够方便地创建PLC，并模拟运行。

运行需求：GTK+ 下载地址：http://www.cr173.com/soft/77431.html

更新日志：

v0.9.11 (31 january 2014)

   - In monitor connect window, added timeout widget entry to adjust timeout wait reply (usefull when using low serial

     speed, modem, ...)

   - Can use PSTN/GSM dialup modem with Hayes AT commands for serial monitor (on slave serial link, and for master connection).

   - New tab "modem" in configure window to set AT sequences for slave monitor and master connect. 

   - New menu entry, to be able to run logic only for one cycle, or freeze current running (when freezed, current rung status

     displayed).

   - Added exit() in end with ctrl-c handler. Else was crashing on exit.

   - If no coil on rungs, and set/unset vars, blue background not refreshed to know that the var is setted. Fixed.

   - If previous project monitored has modbus slaves, and current project none, at a time, monitor asking modbus slaves stats in

     loop, and nothing more. Fixed.

   - New window to set monitor serial config (port name, speed). port can be blank to let a port available for other function

     (modbus master, future modbus slave?, ...)

     For this, added new monitor frame to be able to set speed and serial port name.

     (easier instead of having to edit 'classicladder_prefs' file with vi in telnet!)

   - In Gtk config window, new option in 'misc' tab, to auto adjust summer/winter time.

   - Moved from monitor protocol code to set time clock (Linux & Rtc) in a function to be used per auto summer/winter time

     + code to do summer/winter time switch.