John Navas wrote:
> On Wed, 10 Jan 2007 07:55:54 +1000, Adrian Jansen <adrian@qq.vv.net>
> wrote in <12q83rvd31pcl92@corp.supernews.com>:
>
>> John Navas wrote:
>
>>> My 2nd try, a generic adapter based on the Prolific PL-2303 chip, was
>>> successful -- it plays very well with Windows XP and with my GPS units.
>>> (Prolific-based adapters are used by a number of major OEMs.) ...
>
>>> Although the adapter as supplied by TekGems comes with drivers on a mini
>>> CD, later drivers for Windows (2.0.2.1, XP Logo Certified), Mac, and Red
>>> Hat Linux, can be downloaded directly from Prolific. ...
>
>> We have less problems with USB-Serial devices using FTDI chips than
>> those based on the Prolific ones.
>> Especially when sending short messages back and forth between PC and
>> device, sometimes the Prolific ones need special setups buried way down
>> in the Windoze serial comms control system.
>
> Were you using older Prolific driver versions? I've now run a fair
> number of torture tests against my Prolific PL-2303 with the Windows XP
> driver 2.0.2.1, and all were passed successfully. If you're got
> something legitimate that you think will cause it to fail, I'd be happy
> to try it. (My posting email address is valid.)
>

I cant give you specific driver versions, most of the problems were
reported from remote customers, and may not even have been with XP. We
deal with people who use anything from '98 up. All I can say is that
when we suggested they buy adapters using FTDI chips, most of the
problems ceased.
The Prolific units I tested personally could be got to work, by
adjusting the timeouts and buffer sizes in the comms setup, but I am not
certain some customers followed our recommendations.
However we may have had a special case, since we were sending short
binary packets in both directions. Typical GPS use, where its just one
data stream in one direction is not likely to cause much problem.


--
Regards,

Adrian Jansen adrianjansen at internode dot on dot net
Design Engineer J & K Micro Systems
Microcomputer solutions for industrial control
Note reply address is invalid, convert address above to machine form.