BITADR

Overview

This address operator is not specified by the standard IEC 61131-3.

BITADR returns the bit offset within the segment in a DWORD. The offset value depends on whether the option Byte addressing in the target settings is activated or not.

The highest nibble in that DWORD indicates the memory area:

Memory: 16x40000000

Input: 16x80000000

Output: 16xC0000000

Example in ST

VAR
        var1 AT %IX2.3:BOOL;
        bitoffset: DWORD;
END_VAR
bitoffset:=BITADR(var1); (* Result if byte addressing=TRUE: 16x80000013, if byte addressing=FALSE: 16x80000023 *)

Example in IL

LD     Var1
BITADR
ST     bitoffset

Considerations for Online Changes

Executing the Online Change command can change the contents of addresses.