Hi NI,
Just a suggestion. Why not move the RTSI connector on the full size
PCI boards so they are parallel with the RTSI connectos on the half
size boards? This would make the RTSI cable between these boards
much shorter, increasing transfer rates and reducing 'racing.'
Such a simple redesign would increase perfomance dramatically. I'm
not sure why the current design was ever approved.
Specific example is trying to combine a PCI-6115S with the PCI-7344
motor controller with a RTSI cable. The RTSI connectors are offset
horizontally from each other by 4 or 5 inches. Also, if all the
connectors were parallel to each other, it would be simpler for National
to stock RTSI cables for all configurations. As it is, I am forced to
build my own cable. (IE I have empty slots immediately next to the PCI-
6115s boards, as recommended in the manuals). National should have some
kind of form you can fill out that describes the cable you need. This
would be simple to do if the connectors where all parallel. (ie just
check boxes with up to n slots and fill in the empty circle where you
want a RTSI connection). Also, I think that National probably has the
resources to make a better quality RTSI cable than I do. (eg, shielded?)
Obviously it's too late for the PCI-6115S but they could re-release the
board under a different model number (6115S-n?). IE it's not good to
change a design so radically that replacing a board in the field means
having to replace cables too. For newly manufactured machines (or for
engineering upgrades) it would be ok though.
One other point, I hope this is not to make PXI more desirable (ie
purposely sabotaging the performance of PCI). I would rather think that
it was just missed
on the original design approval or for some other
necessary reason (though it is hard to believe that physics dictated the
position of the RTSI connector).
Thanks for your time,
JT
