USB-Serial Adapter (PL2303) Port Speed

Jacob S. Barrett jbarrett at
Thu Jun 3 15:29:03 GMT 2004

On Wednesday 02 June 2004 14:56, "Jacob S. Barrett" <jbarrett at> 
> I am attempting to use a PL2303 cable to my cell phone as a modem.  All
> works fine under Windows at port speed of 115200.  It works fine under
> FreeBSD at 19200, but nothing higher.  When I set a higher port speed,
> 38400, 57600 or 115200, the ppp chat session times out on the first AT
> command.

I figured it out.  The application that came with the cable executes 
"AT+IPR=19200" when it is done, leaving incapable of connections at any other 
speed.  When the software starts it connects at 19200 then calls 
"AT+IPR=115200" drops and re-connects at 115200.  The phone doesn't seem to 
support "AT+IPR=0" which is autodetect.  Once I connect to it at 19200 and 
set the IPR to 115200 with cu before calling ppp it works fine at 115200.  
Hopes this comment helps someone googling for a solution down the road to a 
similar problem.
Jacob S. Barrett
jbarrett at

"I don't suffer from insanity, I enjoy every minute of it."

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