Overview
The ladder editor of the CODESYS Ladder add-on is a further network-based editor for the IEC programming language Ladder. To distinguish the implementation language from its predecessor, it is named Ladder (LD2).
Tip
The CODESYS Ladder add-on is the modern successor to the still available CODESYS LD FBD add-on. Objects which have been programmed in CODESYS LD FBD can be converted to CODESYS Ladder.
In the implementation part, you program a circuit diagram in one or more network elements. To do so, you can insert the required elements from the toolbox or by means of menu commands, link them, and provide them with input and output variables and modifiers.
Each network can be provided with a title, a comment, and/or a jump label. You can also comment out networks.
Elements are inserted and replaced simply by dragging an element from the toolbox to one of the offered insertion positions.
The insert positions are indicated by the following symbols while you drag the element into the editor and across the ladder diagram:
Square with a gray background inside an element symbol
Rhombus on a connecting line
Triangle pointing up or down for insertion above or below
A possible insert position lights up and the mouse pointer is given a plus sign 
. When you release the mouse button, the element is inserted.
Currently selected areas in the editor are highlighted in red and outlined.
You will find suitable commands for modifying (edge detection, Set/Reset, EN/ENO) as well as for deleting, refactoring, and searching in the context menu.
In online mode, monitoring and debugging using breakpoints and the writing and forcing of values are possible.
The display in the editor is defined in the CODESYS options in the Ladder editor category. This covers, for example, the display of comments, addresses, or whether networks are provided with line breaks.
Programs which have been created in the CODESYS LD FBD editor can be read into the LD2 editor and edited further.