I stored a constant data like "TEST" in one of the 8951, which sends this data continously through its Tx pin.
Then I programmed the other 8951 to receive (polling) any kind of data on its Rx pin and then send the same received data throught its Tx pin (just like ping). Now I connect the Tx pin of the second 8951 to MAX232 and receive it on the PC using a terminal program.

Sometimes "TEST" is received exactly as it is and sometimes something else appears in the terminal program.

But the sequence of correct and incorrect data seems to be same like I receive "TEST" correctly one time and I receive something different like "T$%T" for about four or five times and again receive "TEST" correctly one time and the whole thing repeats over and over again. The error data received - "T$%T" never changes i.e i am receiving either "TEST" or "T$%T" and nothing other that those two.

The distance between the two 8951s is about 3 inches. Baud rate in both the 8951s (including PC serial port) is set to 1,200 with 8 data bits, 1 stop bit and no parity.