RS485 PI Last PV Inverter isn’t answering
The RS485 Pi is an RS485 interface for the Raspberry Pi
07/09/2018
Posted by:
Grisu
I’m using the RS485 PI. I’ve connected 3 Kaco Inverters to it, the last one is not answering. A termination resistor is added at the end.
I’ve also got an USB RS485, this one is working with all three inverters.
Does someone has an advice?
Sebastian
I’ve also got an USB RS485, this one is working with all three inverters.
Does someone has an advice?
Sebastian
07/09/2018
Posted by:
andrew
Hello Sebastian
Are you using a shielded twisted pair cable to join the inverters together? It is possible that the RS485 Pi is more sensitive to noise than your USB device so a twisted cable will give you better noise performance. Maxim has a good article on wiring an RS485 network
You could also try adding a 10K resistor between the Raspberry Pi’s 5V pin and the A output on the RS485 Pi and a second 10K between the ground and B output. This should make the RS485 Pi less susceptible to noise and hopefully solve the problems you are having.
Are you using a shielded twisted pair cable to join the inverters together? It is possible that the RS485 Pi is more sensitive to noise than your USB device so a twisted cable will give you better noise performance. Maxim has a good article on wiring an RS485 network
You could also try adding a 10K resistor between the Raspberry Pi’s 5V pin and the A output on the RS485 Pi and a second 10K between the ground and B output. This should make the RS485 Pi less susceptible to noise and hopefully solve the problems you are having.
16/09/2018
Posted by:
Grisu
Thank you very much, it works great!
Sebastian
Sebastian
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