This function can be used to test the PICs RS232 (receive mode) and all of the hardware involved, e.g. PIC
UART, MAX232 and cable. Since ‘RX terminal’ is called automatically after transmission, it is possible to fully
test RS232 communications, e.g. setup the PIC so that it transmits every character it receives. If the received
message is the same
as the transmitted message clearly RS232 communications is working.