Debug with RS232 device with Raspberry Pi.
Connect Raspberry Pi to RS232 device.
Exchange data from local RS232 to internet.
Questions You Have
Pi-232 is a RPi HAT. Compatible with 3A/3B/3B+/4B.
The ST3232 IC covert TTL UART to RS232.
Raspberry Pi can connect to internet and read/write data to RS232
Standard RPi HAT Dimension