Move bits to byte

Marker bits are legacy step 7 terminology held over.

Just think of them as Booleans / bits that when collected together can make nibbles/bytes/words/dwords.

I just call them M bits to eliminate confusion.

I seems like the term "Marker" is what German translates "flag" to, from the feel of the word and how it is used.

In other PLCs, I might call them "memory bits" because of the M rather than Marker.

polipol

Ok. Now i need find how use markers. :)

Does that help?  If you can do Boolean logic / math, just replace your Boolean variable with an M#.# where # is a number).  Keep in mind, if you are working with words, you might have MW100.15 where this is the 15th bit within memory word 100 (Marker word). 

If you are using symbolic logic with s7-1200/1500, you can get confused with all the absolute addressing.

Moving 8 bits to a byte in symbolic logic is different.

Let's say you assign tag "MyByte" to MB100 (memory byte 100).

MB100.x0 is the 0'th bit of that byte

You can set or reset it like any Boolean (coil).

If you generalize it, that is MB100.x# where # is 0..7 to assign the bits within "MyByte".

When you are done, the byte value is accessible in MyByte.

Maybe this is useful?