Re: [PATCH] Documentation about RS485 serial communications

[Grant Edwards <grant.b.edwards@gmail.com>]

On 2010-11-16, Matt Schulte <matts@commtech-fastcom.com> wrote:

>>> In my opinion this type of card is not that common. ?Generally
>>> speaking the achievable baud rates for this type of multi-protocol
>>> card are very limited because of limitations of the transceiver
>>> chips.
>>
>> I'm curious which selectable interface cards you're talking about
>> that are slow? ?The ones I'm familiar with generally support baud
>> rates up to either 460K bps or 921K bps
>>
>>> It seems that most of the time people would rather have a faster
>>> serial port than one that does several different voltages.
>>
>> Where did you find a selectable interface serial card that couldn't
>> support high baud rates?
>
> In my world 460kbps for an RS422 card is slow.  RS422 cards generally
> push multi megabit/s rates.

Ah, I see.  That's a completely different market than the markets
served by the multi-interface cards that typically max out at 921K.
I've support multi-interface cards for years and years, and I find it
very rare that anybody uses anything much faster than 19.2K.

-- 
Grant Edwards               grant.b.edwards        Yow! TAILFINS!! ... click
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