1. PLC Concepts 1.8 Correcting Ladder Diagram Example 1: Connect the block to the front for omitting ANB instruction because simplified program improves processing speed X0 X1 Instruction List LD X0 LD X1 OR X2 ANB X0 X1 X2 Instruction List LD X1 OR X2 AND X0 X2 1-11 Block combination should be made on top of the circuit. Parallel connection with empty device is not allowed.. Parallel connection with empty device is not allowed. No device in the middle block. Devices and blocks in series should be horizontally aligned Label P0 should be at the first row of the complete network. “Reverse current” exists