There are 2 systems,A and B. Communication between them is via Uart.
As part of periodic health check for CAN Bus, its possible to do a loopback and check the status of the CAN transceiver and the bus(in addition to those taken care of the CAN spec itself like error counters).
Similarly, if my choice is UART for communication, is there any method i can ensure that the Tx and Rx lines are functioning properly without System A having to send a msg to System B and asking System B to retransmit back the same data received by it? I want to make the Health test by each system independent of the other.