UART Initial state

Hi everybody,
 can anyone tell me what should be the potential at the tx and rx lines of
uart at initial state.(whether idle or known state) i read somewhere that
at known state the potential diff is 5v, then the receiver at the other end
can view it as a valid byte as anything potential above 2v is considered as
a valid data. pl explain 

svyamuna wrote:

>  can anyone tell me what should be the potential at the tx and rx lines of
> uart at initial state.(whether idle or known state) i read somewhere that
> at known state the potential diff is 5v, then the receiver at the other end
> can view it as a valid byte as anything potential above 2v is considered as
> a valid data. pl explain

http://en.wikipedia.org/wiki/RS-232#Voltage_levels

-- 
Frank Buss, fb@frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de