Wiring Diagram

[npawelek]

I purchased one of the recommended Industrial RS 485 adapters and after plugging it into my equipment I'm not seeing anything when running od. I've ensured I have the proper serial device (/dev/ttyUSB0), which was confirmed via dmesg. I have an EasyTouch panel with about 15 feet of Cat6A running from the controller serial port (wired only to YEL and GRN), back to the serial adapter plugged into a RPi4. I noticed that the 485 adapter also has a ground, so I'm wondering if I need to wire that, which wasn't explicitly called out in the wiki. I was thinking perhaps it could be the cable length or the lack of ground connection for why I don't see anything. In the raspi-config, I also verified that both serial settings under interface are set to no per the wiki.

Any ideas what I may be doing wrong?

[rstrouse]

Both serial settings? Only the serial console should be turned off.

[npawelek]

Thanks for the response. I swapped the A+ and B- wires and started seeing data that appears to be in the correct format, so that is good. My question around wiring the GND still stands. Is it needed?

On the raspi-config serial options, there's a section in the adapter portion of the wiki that states to set both to "no". Is this incorrect? Looks like it still works with it set this way.

[tagyoureit]

That page hasn't been updated in a long time, but was incorrect as you now see. I changed it.

And no, you don't need to ground the RS-485 adapter.

[npawelek]

Thank you