Logix5000 Controllers General Instructions - SLAC Confluence

496 Special Instructions (FBC, DDT, DTR, PID)Data Transitional (DTR)The DTR instruction passes the Source value through a Mask andcompares the result with the Reference value.Operands:Relay LadderOperand: Type Format DescriptionSource DINT immediate array to compare to the referencetagMask DINT immediatewhich bits to block or passtagReference DINT tag array to compare to the sourceDescription:The DTR instruction passes the Source value through a Mask andcompares the result with the Reference value. The DTR instructionalso writes the masked Source value into the Reference value for thenext comparison. The Source remains unchanged.A “1” in the mask means the data bit is passed. A “0” in the maskmeans the data bit is blocked.When the masked Source differs from the Reference, therung-condition-out goes true for one scan. When the masked Sourceis the same as the Reference, the rung-condition-out is false.ATTENTIONOnline programming with this instruction can be dangerous. Ifthe Reference value is different than the Source value, therung-condition-out goes true. Use caution if you insert thisinstruction when the processor is in Run or Remote Run mode.Publication 1756-RM003I-EN-P - January 2007