Modbus TCP

[Badmintommi]

Hi, I spent so much time with ioBroker/Modbus TCP Adapter.
I want to connect a Modbus TCP Slave to the ioBroker. But it doesn’t work.

Now I bougt a second raspberryPi to conntect to the first raspberryPi via modbus tcp.
I thougth it MUST work because same tool on both sides. But it is not working.

Do you please have an example form me:
2x raspberryPi4 with iobroker and modbus
Connection via Ethernet
Pi-1 = 192.168.178.100 (Master)
Pi-2 = 192.168.178.102 (Slave)

Thank you!
Best regards
Thomas