Re: Enabling RTSI use in NI PCI-6071-E cards

On Wed, Jun 18, 2003 at 05:06:04PM -0400, Calin A. Culianu wrote:
> I don't know if
> national instruments publishes specifications on specifically _how_ to
> talk to these boards to program them so they do RTSI... if it does then
> you could invest in writing extensions to comedi and/or the ni_pcimio
> driver to support this.


RTSI is essentially just a 12-or-so line digital bus connecting
multiple boards in a computer.  Most of the lines are fully
configurable, i.e., you can route many signals on a given board
directly to a RTSI line, and route the same RTSI line to a
triggering signal on another board.  In that sense, it's not
much more sophisticated than just using the PFI lines, and
connecting them appropriately, except that you can of course do
all the routing in software.

One of the big advantages, however, is the possibility of slaving
the master clock of one board to another.  That means that N khz
will not get out of sync on the two boards.

All the documentation is available, and it's not very complicated.
It fits nicely into the Comedi architecture -- one can add an RTSI
subdevice to any of the NI drivers, and either control the RTSI
bus directly from a user application, or develop a virtual driver
that wraps multiple devices and presents them as one synchonized
device.



dave...

Received on 2003-06-18Z20:38:58