In case of several Ethernet connections to
one automation system, how do I define through which Ethernet CP of
an S7 the online connection (status/ control) to the CPU is
The following screenshot shows the
configuration of an S7-300 station with two Industrial Ethernet CPs
connected to the same subnet. If you want to establish an online
connection to the CPU with a PG connected to the same Industrial
Ethernet subnet, then there are two possiblities:
- Online connection to the CPU through the CP 343-1 (Rack = 0,
slot = 4)
- Online connection to the CPU through the CP 343-1 IT (Rack = 0,
slot = 5)
Fig. 1: Project configuration
The access path of the PG to the CPU can be chosen as
- Open your S7 Project with SIMATIC Manager.
- Connect your PG online to the S7 control by clicking button
online in the menu bar.
Fig. 2: Online connection to S7
- Highlight the S7 program of the CPU and open the
object properties of S7 program by clicking the right mouse
- In tab "Addresses: Module" you can now specify the PGs' online
path to the CPU through the IP address.
Fig. 3: Selecting the online path to the CPU