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.
To connect with these PLC use ConnectTo() just like the other “S7” CPUs.
The only difference is that Rack and Slot are fixed (Rack=0, Slot=0).
Also SetConnectionType() can be used.
To access a DB in S71500 some additional setting plc-side are needed.
1. Only global DBs can be accessed.
2. The optimized block access must be turned off.
3. The access level must be “full” and the “connection mechanism” must allow GET/PUT.
Let’s see these settings in TIA Portal V12
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.