Raspberry Pi 3B with UART-RS485 adapter

After a long search, the UART operation was configured and configured properly. USB - RS485 adapter, I don't like how it works with a failure. Having transferred the output of the main UART to GPIO 14 and 15, having disconnected Bluetooth from it, I use an ordinary UART-RS486 adapter for Arduino boards from the Chinese. Question!!!
Request response from Master to Slave on the line without complaints. I check by scanning the RS 485 line. But Master (Node-Red) outputs the Time out message. Which GPIO output should control the flow and connect to the de and RE pins on the Chinese adapter? Where and how should it be registered? Apparently, this is only the case because the request response continues in the line even when there is no connection at all to DE and RE.
Please help me with some advice! Three weeks of searching did not yield positive results. I have already reinstalled the system on raspberry several times. I apologize for my English with google translator.