Logix5000 Controllers General Instructions - SLAC Confluence

490 Special Instructions (FBC, DDT, DTR, PID)Selecting the search modeIf You Want To DetectOne mismatch at a timeAll mismatchesSelect This ModeSet the .IN bit in the compare CONTROL structure.Each time the rung-condition-in goes from false to true, the DDT instruction searches forthe next mismatch between the Source and Reference arrays. Upon finding a mismatch,the instruction sets the .FD bit, records the position of the mismatch, and stopsexecuting.Clear the .IN bit in the compare CONTROL structure.Each time the rung-condition-in goes from false to true, the DDT instruction searches forall mismatches between the Source and Reference arrays.Arithmetic Status Flags:not affectedFault Conditions:A Major Fault Will Occur If Fault Type: Fault CodeResult.POS > size of Result array 4 20Publication 1756-RM003I-EN-P - January 2007