In RS485 communication I receive everything I send, how do I disable this return (echo)?

[EGerh.1]

I'm working on a driver present in the Linux 5.4 kernel. In RS485 communication I receive everything I send, without being connected to another device to return what I sent.

I use the command echo -e "Test" > /dev/ttyLP0 for the submission.

I know that by default in RS485 communication I receive everything I send, but I want to disable the return (echo).

BUG:

My setup is:

PLC - Programmable Logic Controller

Processor: LS1027 (It's not a ST processor)

Linux Kernel 5.4 (tty driver present in this kernel version, who owns the stm32-usart.c)

I use a USB logic analyzer to analyze the signal sent through the echo -e "Test" > /dev/ttyLP0. With rs485 serial pins: D+, D- and GND.

Hardware:

Best regards

Eduardo Gerhardt