Hello

I am testing the communication between an S7-1500 PLC and an S7-300 PLC. The S7-300 PLC consists of a CPU 314-2PN/DP and a CP343-1 Lean.

In the hardware configuration of Step 7, I set the Profinet port of the CPU to the IP address 192.168.1.3 with subnet 1. In the CP343, I configure the same IP address but with subnet 2.

Then, in the TIA Portal, I configure the CPU 1511c-1PN, enable PUT/GET, and create OB1 with SFB14 GET, reading from the IP address 192.168.1.3.

When I connect the S7-1500 CPU directly to the S7-300 CPU via the Profinet port, everything works perfectly. However, when the connection is between the CPU-1500 and the CP343-1, I am unable to read data. The FB14 block has its error output set to 1, and the status output is also set to 1.

In the CP343-1, in the special diagnostics section, the counter for rejected S7 connection attempts keeps increasing continuously.