1766-RM001A-EN-P MicroLogix 1400 Programmable Controllers ...

96 Programming Instructions OverviewIndirect Addressing of Bit0002B3:0[B25:0]B3:0100003 END• Address: B3/[B25:0]• Description: In this example, the element to be used for theindirection is B25:0. The data in B25:0 defines the bit within file B3.If the value of location B25:0 = 1017, the XIC instruction isprocessed using B3/1017.TIPIf a number larger than 4096 (or larger than the number of elements inthe data file) is placed in B25:0 in this example, data integrity cannotbe guaranteed. Exceeding the number of elements in the data filewould cause the file boundary to be crossed.These are only some of the examples that can be used; others include:• File and Element Indirection: N[N10:0]:[N25:0]• Input Slot Indirection: I1:[N7:0].0Each group of instructions may or may not allow indirection. Pleasereview the compatibility table for each instruction to determine whichelements within an instruction support indirection.IMPORTANTYou must exercise extreme care when using indirect addressing. Always beaware of the possibility of crossing file boundaries or pointing to data thatwas not intended to be used.Publication 1766-RM001A-EN-P - October 2008