David Billington fired this volley in
:

Any idea what language you'll
be using, my experience is with C and C++.


I can do C, and a smattering of C++. I retired from software work before
C++ had a full following among industrial users, but C was well and
thoroughly rolled out.

However, I'm most likely to do it in Visual Basic. It's not all that
great a language in terms of efficiency, but I have a library of hardware
functions and widgets that claim to deal with all the preemption crap.
Obviously, at 4800 baud, interrupt latency is important. Coupling that
with the fact that the control will choke if you send more than three
characters past the XOFF makes real-time handling pretty important.


Dave, I could not figure out how to make the control use Xon/Xoff "dumb"
protocol for the DNC. I followed your instructions of using a "-1" as
the filename, but my termulator still just blithely sent the whole file,
rather than pausing per-block. I don't yet have a protocol analyser
hooked up, but I presume that means there were no flow-control characters
coming from the control.

OTOH, I can transmit a DNC stream successfully from EZlink, using ONLY a
"-" as the filename (at the control) and two executes. The first one
seems to set the protocol, and the second starts the DNC link.

Perhaps you could explain that -- what is the significance of the "bare"
minus sign as a filename? I just did that from rote per the EZLink
instructions, but have no idea what it does. Can the DNC protocol be
invoked with a "real" filename, also? (haven't tried yet)

I air milled several parts yesterday under DNC via EZLink.

Thanks,
LLoyd