Siemens ET 200pro Operating Instructions Manual page 145

Principle of operation
The figure below highlights the principles of grouping.
Figure 5-1
No grouping of electronic modules
If you choose not to group digital output modules in a single byte when you configure the
ET 200pro distributed I/O system, select only the module names which do not contain the "*"
character from the hardware catalog of your configuration software.
Each electronic module will then occupy 1 byte in the process output image.
See also
Configuring by Means of GSD File (Page 140)
Example of a configuration (Page 146)
ET 200pro distributed I/O system
Operating Instructions, 03/2013, A5E00335544-08
Grouping of digital output modules
Configuring
5.1 PROFIBUS DP
145