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Example - Ladder Diagram

D<​

The D< instruction compares a DWORD value, S1, to another DWORD value, S2, and executes if S1 is less than S2.

LDD Execution Condition​


When the result of the instruction execution of the expression D0 < D2 (986,542 < -23,461) is FALSE, the coil, Y1.3, is deenergized.



When the result of the instruction execution of the expression D0 < D2 (-325,654 < -23,461) is TRUE, the coil, Y1.3, is energized.

Memory Monitor​

ANDD Execution Condition​


When the result of the instruction execution of the expression D5 < D7 (83,648 < 25,652) is FALSE, and the contact, M0.0 is ON (1), the coil, Y1.4, is deenergized.



When the result of the instruction execution of the expression D5 < D7 (-83,648 < 25,652) is TRUE, and the contact, M0.0 is ON (1), the coil, Y1.4, is energized.

Memory Monitor​

ORD Execution Condition​


When the result of the instruction execution of the expression D10 < D12 (2,356,655 < -265,578) is FALSE, or the contact, M0.1 is ON (1), the coil, Y1.5, is energized.



When the result of the instruction execution of the expression D10 < D12 (8,954 < 851,582) is TRUE, and the contact, M0.1 is OFF (0), the coil, Y1.5, is energized.

Memory Monitor​