Serial Port Baud Rate at 250k/s ?

E

Thread Starter

Ernie Tseng

I am doing some serial communication with J1939 messages. The baud rate it is transmitting over a CAN card is 250k/s. I was wondering if it is possible for the com port to be at that baud rate too. can anyone help me on this?
 
L
Well, it sounds like you want to funnel CAN data directly to a PC.

You can buy computer async com ports that go up to 450k or more (see black-box and many, many others). However, CAN is not async & does *NOT*
restrict itself to 7 or 8-bit chars. So in theory you could "convert" the CAN message to a series of 8-bit binary chars & then handle them on a
computer. The company D.I.P. (for example) has such a product. But what you see at the computer will not be pure CAN-bus traffic but an approximation of it reformed for 8-bit async chars.

Regards

Lynn August Linse, Senior Product Application Engineer
15353 Barranca Parkway, Lantronix Inc, Irvine CA 92618
[email protected] www.lantronix.com
Tel: (949)300-6337 Fax: (949)453-7132
 
> I am doing some serial communication with J1939 messages. The baud rate it is transmitting over a CAN card is 250k/s. I was wondering if it is possible for the com port to be at that baud rate too. can anyone help me on this?

1. Lynn is right. CAN data frame is not the same as the RS232 8,N,1 frame. The signal level is not the same either. You would need a convertor. B&B also has one.

2. You can program the com port to any baud rate you like (within the limit of the dividor) if you access the hardware directly. However, the UART would still be looking for the start, date bits and stop bit frame.

Regards

Eric
 
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