RS485 network not running... please help!

[kduino]

Hi Kisse66,

thank you very much for this advice. Most of the forum writers are pointing on the terminating resistors, but in my experience they are not the key.
I put two 680R from B to GND and A to 5V and the reliability I experienced has improved tremendously!
Thank you for the hint.

Another question I have: The gateway is receiving the messages now but there is no ACK. How can I ask for an ack for security relevant messages?

Thank you
By kduino