Logix5000 Controllers General Instructions - SLAC Confluence

Sequencer Instructions (SQI, SQO, SQL) 431Description:When enabled, the SQL instruction increments to the next position inthe sequencer array and loads the Source value into that position. Ifthe .DN bit is set or if .POS ≥ .LEN, the instruction sets .POS=1.Typically use the same CONTROL structure as the SQI andSQO instructions.IMPORTANTYou must test and confirm that the instruction doesn’t change data that you don’twant it to change.The SQL instruction operates on contiguous memory. In some cases, the instructionloads data past the array into other members of the tag. This happens if the length istoo big and the tag is a user-defined data type.Arithmetic Status Flags:not affectedFault Conditions:A Major Fault Will Occur If Fault Type Fault CodeLength > size of Array 4 20Execution:Conditionprescanrung-condition-in is falseRelay Ladder ActionThe .EN bit is set to prevent a false load when the program scan begins.The rung-condition-out is set to false.The .EN bit is cleared.The rung-condition-out is set to false.Publication 1756-RM003I-EN-P - January 2007