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Chapter 4. Ladder Diagram (LD) Programming
4.2.1
Data Lengths for the Bit Operation Functions
The Bit Operation functions operate on a single WORD or DWORD of data or up to 256 WORDs or
DWORDs that occupy adjacent memory locations.
Bit Operation functions treat the WORD or DWORD data as a continuous string of bits, with bit 1 of
the first WORD or DWORD being the Least Significant Bit (LSB). The last bit of the last WORD or
DWORD is the Most Significant Bit (MSB). For example, if you specify three WORDs of data beginning
at reference %R0100, they are treated as 48 contiguous bits.
Overlapping input and output reference address ranges in multiword
functions is not recommended, as it can produce unexpected results.
Note that for all functions (Bit Test, Bit Set, Bit Clear, and Bit Position) that return a bit position
indicator as an output parameter (POS), bit position numbering starts at 1, not 0, as shown in the
diagram above.
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PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
Warning
GFK-2950C
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