S7 1200 1500 Notes
This is taken directly from Snap7 documentation: http://snap7.sourceforge.net/
An external equipment can access to S71200/1500 CPU using the S7 “base” protocol, only working as an HMI, i.e. only basic data transfer are allowed. All other PG operations (control/directory/etc..) must follow the extended protocol, not (yet) covered by Snap7. Particularly to access a DB in S71500 some additional setting plc-side are needed.
- Only global DBs can be accessed.
- The optimized block access must be turned off.
- The access level must be “full” and the “connection mechanism” must allow GET/PUT.
Let’s see these settings in TIA Portal V12
DB property
Select the DB in the left pane under “Program blocks” and press Alt-Enter (or in the contextual menu select “Properties…”)
Uncheck Optimized block access, by default it’s checked.
Select the CPU project in the left pane and press Alt-Enter (or in the contextual menu select “Properties…”) In the item Protection, select “Full access” and Check “Permit access with PUT/GET ….” as in figure.
