Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
11/17/08 19:57
Read: times


 
Msg Score: +1
 +1 Informative		 #160097 - Loopback?
Responding to: ???'s previous message
Ellappan Varadharaj said:
i used the loop back test.

What loop back test?

it worked properly.

So the particular loop that you tested is working OK - you need to move the loopback until you find the location of the problem!

  • If you put a loopback direct onto the PC's COM port connector, you have only tested the PC's COM port;

  • If you put a loopback on the end of your cable, you have tested both the PC's COM port and the cable;

  • If you remove your 8051 from your board, and put a loopback between the Rx and Tx pins, you have tested everything up to the 8051 pins - ie, all the hardware;

  • The next step would be to implement a software loopback within the 8051: if that fails, when all the others have worked, it shows that the fault is in your software.

    As Per says, from the symptoms you describe, it is most likely that you have your serial settings wrong - baud rate, parity, etc...

    • List of 8 messages in thread
    TopicAuthorDate
    about serial communication problem            01/01/70 00:00      
       be more specific            01/01/70 00:00      
          check baudrate            01/01/70 00:00      
       Loopback?            01/01/70 00:00      
       more specified            01/01/70 00:00      
          Just Exactly what do you mean by "not working"?            01/01/70 00:00      
          SIO init possibly wrong            01/01/70 00:00      
       UART and PC hyper terminal            01/01/70 00:00      

    Back to Subject List