Bo Berglund wrote:
But that is about it. We never ever used any of the other functionality
of AP like the different protocols and stuff. Just the simple port.
And that is what I would like to have also with FPC/Lazarus. I could even
live without the TCP/IP mode.
So if you have code to implement the simple serial comm system outlined
above I'd be very interested to try that out.
My immediate application calls for communicating with a data acquisition
device with a binary data transfer protocol, so I need all 256 byte codes
to pass transparently through to my application. There must be no
interception
based on data values. Example of packet structure:
<type><blocklength><data><crc>
All binary of course.
On Windows, we use (an older version of) Dejan Crnila's TComPort. On
Linux I'm currently using FPC's standard serial unit, wrapped in a
class. In both cases I've hacked things a bit to expose a few extra
facilities, e.g. to make sure I can get at both Ring and CD and to do
reads with timeouts.
In my opinion most comms libraries got top-heavy with facilities to
handle things like call control and faxing which should have been
completely separate layers. However my interest is interfacing with
scientific instruments etc. rather than the minutae of VT-100 emulation,
other people might disagree. I've also got some very definite ideas on
modem handling and have the equipment to monitor traffic, and I don't
want anything getting in the way.
I presume you're aware of Wolfgang Erhardt's Pascal CRC code, so I won't
mention it here :-)
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
--
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