Power rails
The left power rail is a vertical line that delimits the rung in the LD-editor on the left. Similar to this, the right power rail is a vertical line that delimits the rung in the LD-editor on the right.
The state of the left power rail is considered ON at all times. No state is defined for the right power rail. See "Link elements (lines) and their states in LD" for more information on the power flow of a ladder diagram.
Representation
Example for an empty rung with the left and right power rail:
Actions for power rails
There are no specific actions provided for the power rails. See "Actions within LD-editor" for a list of all possible actions.