IO

Definition

Module - Core-3588SJD4-AI

Phoenix terminal pin definition

RS232 Interface Definition

Module - Core-3576JD4

Phoenix terminal pin definition

RS232 Interface Definition

RS485 RE-DE PIN USE

For example, to operate "122", you need:

Export the GPIO, run as root user:  echo 122 > /sys/class/gpio/export

Operate GPIO, set to read input or output specified value:  cd
/sys/class/gpio/gpio122  # Set GPIO output mode echo out > direction #
GPIO outputs low level, RS485 is set to data receiving mode echo 0 >
value # GPIO outputs high level, RS485 is set to data receiving mode
echo 1 > value

There are a few things to note:

If the GPIO has been applied by other drivers, it cannot be exported
successfully, and subsequent read and write operations cannot be
performed.

Involving the multiplexing of IO functions, if the function of the pin
is already GPIO, the above method can be used; otherwise, the pinctrl
state must be specified in the device tree.