Ladder logic is a graphical programming language which means that instead of text, the programming is done by combining different graphic elements. These graphic elements are called symbols. One of the smart things about the ladder logic symbols is that they are made to look like electrical symbols. Ladder logic was originally created for technicians, electricians and people with an electrical background. People who are used to look at electrical diagrams and schematics. Take a look at the symbols and see if you think they look familiar. Just as in electrical diagrams ladder logic have symbols for contacts and relays (which are called coils in ladder logic). The symbols may look a little different from the ones you find in electrical schematics, but they have almost the same functions. Ladder logic example - Oil motor start then main motor start: - Providing lubricant for the gear box before the lathe spindle starts to run which aims to ensure that the oil pump motor starts first and the main motor starts subsequently. Number of PLC Inputs Required X0 – START pushbutton to Start Oil Pump Motor X1 – START pushbutton to Stop Main Motor X2 – STOP pushbutton to Stop Oil Pump Motor X3 – STOP pushbutton to Stop Main Motor Number of PLC Outputs Required      Y0 – Oil Pump Motor      Y1 – Main Motor PLC Ladder Programming Description:       This program is a typical application of the conditional control circuit. Y0 = ON when Oil Pump START button is pressed. Therefore, the oil pump will start to provide lube for the gear box of main motor(Y1)        Under the precondition of the operating state of the Oil pump, the main motor (Y1) will be ON when the Main motor START button is pressed.         During the operation of main motor (Y1), oil pump (Y0) needs to provide lube continuously.        The oil pump will be stopped when Oil pump STOP button X2 is activated, and the main motor will be stopped when Main motor STOP button X3 is activated.  Follow Us On : Google Reviews : https://goo.gl/LxpEsU Facebook : https://www.facebook.com/wscubetech.india Twitter : https://twitter.com/wscube Linkedin : https://www.linkedin.com/company/wscube-tech Google + : https://plus.google.com/+wscubetechjodhpur Youtube : https://www.youtube.com/c/wscubetechjodhpur Website : http://wscubetech.com
