hi gmt,

its not clear what you want. 

I think you want to know how many modules can be installed on the right side of the CPU.

See following manual for the rules of installation on a single rack(chapter 4.5) and on several racks(chapter 4.6).

hope this is the information you are searching for,

regards,

edit: Link repair 

gmt86

please
an S7-300 can take the maximun how expansion module (input / output)?

Usually in central rack: 8 modules.

You may use central Extension by IM360, IM361, IM365 for additional central racks
and you may use profibus DP Station for decentral extention racks.

gmt86

yes but the link does not open

[ LINK1 ]  // Title search

[ LINK2 ] // Chapter 4.5

[ LINK3 ] // Chapter 4.6

[ LINK4 ] // For an offline copy for future reference