Mnemonics in the LD Language
At each variable can be associated a mnemonic. It is then possible to
use the mnemonic or variable completely transparently in programs.
To associate the variable Switch to the input %I0, the variables RedLight and GreenLight to the outputs %Q0 and %Q1 respectively, it is possible to specify them during the variable declaration in the Ladder editor:
In the Ladder code Editor, the variables appear: