I seem to have run into a problem. I am using MAX485 (RS485 to ttl, at uno side) and MAX485 (RS485 to USB serial @ at pi side). Now the problem is that this simple setup works at shorter distance,(tested 10 meters). But now I have got a reel of 305 meters(cat 6E, shielded) and it’s not working.
There is absolutely no voltage drop across the terminal.
The wires are properly crimped
The resistance across the end of each wire is 56-57 ohm.
Below image is only for reference, there is no special code as I am using this only for simple data transfer. Not master slave configuration. I have two separate TRANSRECEIVER for full duplex connection. So, one of them is always in receiving state(de,re pin set to low at all times) and other is sending(de,re untouched).
@system if you could weigh in please. I would be very great full