Logix5000 Controllers General Instructions - SLAC Confluence

Function Block Attributes 643This example is the same as the one above. The value of tagA isstored only once at the beginning of the routine’s execution. Theroutine uses this stored value throughout the routine.Block_01tagABlock_02tagAStarting with RSLogix 5000 software, version 11, you can use the sametag in multiple IREFs and an OREF in the same routine. Because thevalues of tags in IREFs are latched every scan through the routine, allIREFs will use the same value, even if an OREF obtains a different tagvalue during execution of the routine. In this example, if tagA has avalue of 25.4 when the routine starts executing this scan, andBlock_01 changes the value of tagA to 50.9, the second IREF wiredinto Block_02 will still use a value of 25.4 when Block_02 executesthis scan. The new tagA value of 50.9 will not be used by any IREFs inthis routine until the start of the next scan.Publication 1756-RM003I-EN-P - January 2007