what is the maximum baudrate of rs232 supported by PC?

[omidsht]

hi ,
i have a avr circuit which should have a uart communication(rs232) with pc at least 230.4kbps or more , does the computer comport support this baud rate ?
if no ,  what shall i do ?
thanks and wiating for your guide .
 
OMID

[matjazl]

You coud use  230.4kbps.
The maximum baud rate in hyper terminal for COM port is 921600 bits per second.

[Bepo]

It depends of the USART installed on your motherboard.
Normally 230.4 kbps is the maximum speed supported, but older PCs may have a lower maximum limit.
Check, if possible, the user manual

Bye

[engr.humair]

921600bps

[kiemsidatinh]

       PC using IC 8959 of Intel (standard) so max speed about 115 Kbps but max speed belong to the distance. When the distance is longer, the speed is the slower.

[bliviudaniel]

I have just took a look in Hyperterminal and I've seen that the maximum selectable baudrate is 921.6k. And 230.4k is one valid option that could be choosen. So I think you may try to use 230.4k. Good luck!

[digitalmg]

With virtual serial port ex.FT232R the max speed is 3Mbps.

[yoda]

       ......but max speed belong to the distance. When the distance is longer, the speed is the slower.

I think you want to say that at longer cables (longer distance) you should use a lower baudrate. So for using the highest possible baudrate, start with the shortest cable you can affort ( about 1 meter or so ). Also the quality of the cable is important, watch out for capacitance (to ground) which will slow down the steepness of the rise and fall edges of the waveform, or changes it from block to sinus-like signals. Then the timing will get corrupt for example.
Maybe you know all this, but sometimes people forget it and use a too-long cable. 
bye.

[kiemsidatinh]

        Oh, yeh, if anybody want the max speed, they should use the cable which has got the small distance (< 50cm) ang high quality cable. Good luck for U.

[omidsht]

thanks friends for your answers , but !
1-yes , in hyper terminal there speed up to 900mbps , but we should see hich are possible in practice .

2- if 230kbps is supported by pc , ho should i coonect avr to pc  ? i mean the max232 i (convert ttl to rs232) only supports up to 130kbps (according to the datasheet of max232) , so what shall i do ? is there any ic like max232 but with more baud rate supported ? (i need 230kbps)

thanks
waiting for your guide

Omid

[yoda]

is there any ic like max232 but with more baud rate supported ? (i need 230kbps)
Omid

Hallo Omid,
I don't know but maybe the (older) 1488 and 1489 are faster.
There is also the 75155 (only one receiver and one transmitter in 8pins dip) which has a propagation delaytime better than 0,5u sec (500 ns).
Can you explain why you need 230 kB/s ?

Regards, yoda.

[omidsht]

hi ,
i want to convert ARINC429 protocol to RS232 .
ARINC429 is a 100kbps protocol and it is used in aircraft systems , according to my calculation i should use atleast 130kbps or more to do it .
if you have any idea please let me know

regards
omid

[yoda]

if you have any idea please let me know

Hi Omid,
I don't have a better idea for you, I should try the 75155 driver (Texas Instruments).
Succes, yoda.

[foxelec]

Hi friends,

the MAX3230E/MAX3231E seems to be ok for your needs.

foxelec.