Re: Need high speed RS232 interconnect
- From: "Roger Hamlett" <rogerspamignored@xxxxxxxxxxxxxxxxxxx>
- Date: Tue, 30 May 2006 15:42:27 GMT
"Boki" <bokiteam@xxxxxxxxxxxxxx> wrote in message
news:1148886100.982027.8340@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi All,Key thing, is that it is unlikely that the embedded device is 'RS232', if
I need a RS232 (PC to embedded device) interconnect/interface that
support 460.8Kbps/921.6Kbps ( higher is better )
Thank you very much!
Best regards,
Boki.
it supports this high a data rate. RS232, is an electrical signalling
spec, _not_ the specification for asynchronous serial data, which the term
is often used (incorrectly) for. I'd strongly suspect that the embedded
device is 'TTL serial', _not_ 'RS232', since this is beyond the specified
rates supported by RS232, and even using extrapolation from the RS232
figures, the cable lengths that would be supported at this rate, would be
tiny.
Hence, making the assumption, that what is needed is actually TTL
asynchronous serial, _not_ 'RS232', then the second question is whether
the device actually supports this rate without handshaking. Few devices an
handle this sort of rate continuously. Now looking at the USB interfaces
that mny posters have mentioned. A lot of such devices support high
interface rates like this, but only on the local interconnection. Most
USB-RS232 adapters, are at heart USB HID devices, and even those
supporting 'high speed' operation, will only achieve 64,000Bps max, and
therefore will have trouble handling a serial bus over 640,000bps. Above
this, they only transfer at these rates for a short moment, till the
buffer is full, and if 'RS232' signalling is used, the maximum cable
lengths are then only a few inches to the device.
Start by saving a lot of effort, and get the data sheet for the 'embedded'
device. If it is yet to be designed, look at a standard like RS422, rather
than RS232. Once you actually have the signalling standard involved, then
there are PCI cards, or block mode USB devices, that can comfortably
handle signalling at these rates. At present, your question is a bit too
'open'. There are hundreds of devices that can operate a serial bus at
these higher rates, but few that can do it for any length of time, and if
the cabling needs to be more than a very few inches long, it is unlikely
that the connection is 'RS232'.
Best Wishes
.
- References:
- Need high speed RS232 interconnect
- From: Boki
- Need high speed RS232 interconnect
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