Logix5000 Controllers General Instructions - SLAC Confluence

Bit Instructions (XIC, XIO, OTE, OTL, OTU, ONS, OSR, OSF, OSRI, OSFI) 81Execution:Conditionprescanrung-condition-in is falseRelay Ladder ActionThe storage bit is set to prevent an invalid trigger during the first scan.The rung-condition-out is set to false.The storage bit is cleared.The rung-condition-out is set to false.rung-condition-in is trueexamine storage bitstorage bit = 0storage bit is setrung-condition-out isstorage bit = 1storage bit remains setrung-condition-out is setendpostscanThe storage bit is cleared.The rung-condition-out is set to false.Example:You typically precede the ONS instruction with an input instructionbecause you scan the ONS instruction when it is enabled and when itis disabled for it to operate correctly. Once the ONS instruction isenabled, the rung-condition-in must go clear or the storage bit mustbe cleared for the ONS instruction to be enabled again.Publication 1756-RM003I-EN-P - January 2007