Technical data

Basics of Creating Logic Blocks
10.5 Editing LAD Elements in the Code Section
Programming with STEP 7
258 Manual, 05/2010, A5E02789666-01
10.5.3 Illegal Logic Operations in Ladder
Power Flow from Right to Left
No branches may be created which may cause power to flow in the reverse direction. The following
figure shows an example: With signal state "0" at I 1.4 a power flow from right to left would result
at I 6.8. This is not permitted.
Short Circuit
No branches may be created which cause a short circuit. The following figure shows an example: