Indirect Bit Addressing 5000 vs 500

I use a lot of indirect addressing in my programs.

In a Rockwell Logix500 (Micro, SLC500, etc..) system, indirect addressing of bits is pretty straight forward, but I've yet to find similar way on the Logix5000 (Compact, Control, etc...) platform to indirectly address BITS.

Logix5000 follows WORD indirect addressing in a similar manner as Logix500, but with BITS it requires the LOOOONG string shown in the attached pic.

I got the Logix5000 technique from the KB, but maybe one of you gee-wizards can show me how to clean this up (or not)

Maybe its just what I have to live with for....progress...?

Thanks!

There is a fundamental difference between the CLX boolean data type and a bit. The boolean is not the same thing as a B file/word bit. Its a new animal that was not a part of SLC/Micrologix/PLC5s. In planning your program you need to think a little differently about BOOLs, and revise old bad habits on how you thought about B files in Logix500.

Unless its a part of an array or a UDT, a single boolean data tag has a full 32 bit word allocated to it. (actually its more because the tag also includes the tag name). If you really want a RSLogix 500 equivalent to a B file then define a DINT array. After all a RSLogix500 B file/word is really an integer file/word and you can do any operations on it that you can on an N file/word (which is not necessarily the case with a CLX boolean). A boolean array may be an acceptable alternative, just keep in mind that it still won't let you do some of the things you did to B addresses in RSLogix500 - this is where the part about thinking differently about them as you plan your program comes in.

Search the forum for some examples of "bit overlays" that allow you to create DINTs that have named bits, ie, a bit overlay lets you name bits of a DINT, like giving DintTag.0 a tag name like DintTag.BitName that allows you to address bits both by bit number as well as by name. (similar to the way timer bits are named the DN, EN, TT bit) If you choose that option then plan your bit overlay very carefully. You cannot change it once it is defined, you can only delete it and recreate a replacement and you must do that offline.