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Question asked by VRFuser on Jul 29, 1996
send q VRf-A_BINBLOCK vrf ww

from: Greg Goebel / HP-MXD / 970-679-3030 / FAX 970-679-5971
to:   Russ McCrory / VRf
date: Tuesday, 30 July 1996 1212 MDT


Regarding previous correspondence:

> > Anyway, I have a Measurement Coprocessor program that I use to generate a
> > #A block, which has the format:
> >
> >   #A<16-bit-integer><byte><byte> ... <byte>
> >
> > [Workaround follows.]
> I tried this and it works. Thanks!
> I also have a theory concerning the excess byte count. The excess byte count
> occurs because of the assumption that the data is in a REAL64 format, which
> requires 8 bytes.
> The HP 8720 is trying to supply 1206 bytes (0x04b6) of data. If we require 8
> bytes of data per sample then this gives us 150 samples - plus some left
> over bytes.
> However consider the following: The HP 8720c displays 201 data points by
> default. If we use this number to back out the number of bytes requires per
> sample we find that 1206/201 = 6 bytes with no remainders.
> I find this second explanation more plausible.  Can anyone confirm this
> for me?

Don't know enough about the box to say that myself, sir.  However, one
question:  did you test the workaround enough to determine exactly how
many "spare" bytes are being sent?  Is is really six (you could tweak the
array size in the last transaction ... you'll get a timeout if you ask for
more bytes than the device is sending back.)

This may be an important fact because if you don't clear out the entire
transaction and then try to talk to the 8720 again, it may get its little
silicon brain confused.

> My problem now is trying to get the calibration coefficients back into the
> HP 8720. I have used the "INPUCALC" command without much success. I think
> the problem is with the way VEE is handling the binblock output. Any ideas
> for a work around?

I don't see that the example program is doing a BINBLOCK for those
parameters.  Do you have the precise syntax (from the 8720 manual) for this
INPUCALC command?  You might fax the manual page if it's too complicated to
email so I can investigate.

> Thanks
> Russ McCrory
> Georgia Tech Research Institute -     Voice: (404) 894-7096     Fax: (404)
> 894-7080

Please stay in touch.

[<>] regards -- gvg