siemens adressing..

In simatic manager when we take MW1 then why we cant take MW2,rather it jumps to MW3 ??

Always address even bytes in Siemens S7.
MW0, MW2, MW4 ... etc.
DB1.DBW0, DB1.DBW2, DB1.DBW4 ... etc.

Siemens Addressing

In addition to what Jesper have said, there is an overlap between MW1 & MW2

MW1= MB1+MB2
MW2= MB2+MB3
If you could notice MB2 is the upper byte of MW1 , in the same time it is the lower byte of MW2.

To avoid this overlap there is an offset of two bytes when dealing with words, & an offset of four bytes when dealing with double words

MW0,MW2,MW4, etc....
MD0,MD4,MD8,etc...


Hagos

Edited.

Duplicated advice,

Nick

Time to go back to basics
Siemens always uses even numbers as mentioned. You can use uneven, but is not advised unless you know what you are doing.

1 byte = 8 bits
1 word (word-int-bcd) = 2 bytes
1 dword (dint-real) = 4 bytes

Just fool around with it in a DB. You will see how things divide out.