From: Axel Kohlmeyer (
Date: Tue Nov 01 2011 - 08:15:36 CDT

hi tristan,

On Tue, Nov 1, 2011 at 3:16 AM, Tristan Croll <> wrote:
> Hi,
> My local IT guru and I have just spent the better part of a day banging our
> heads against a problem that has the same appearance as a previous one
> mentioned in the VMD list (starting at
> Wed

hmm... this problem has been tracked down to an incompatibility
in the behavior of the (rather old) VRPN client code in VMD and
the newer server code in VRPN-ICMS. so using a VMD binary
linked against a newer VRPN library resolved that for real.

> connected a Novint Falcon, used the demo program to confirm it was working
> properly, and used the vrpn test programs to confirm that vrpn was
> communicating OK. Yet when we tried to connect through VMD, however, it
> refused to connect, with error messages identical to those described in the
> message I linked above.
> Anyway, the problem was eventually (and rather bizarrely) solved by rolling
> our NVidia drivers back from 285.05.09-285.05.09-139.el6.x86_64 to
> 280.13-280.13-138.el6.x86_64.

that is unusual and unexpected. i have no idea how this would
correlate to the connection issues, but thanks for letting us know.

> Thought it was worth a mention, for weirdness if nothing else.

since you spent already some time on this, would you mind
doing one more test? and use the contributed alpha test
binaries of VMD that include the new VRPN client code?
those should allow you to work with the newer nvidia drivers.


> Cheers,
> Tristan

Dr. Axel Kohlmeyer
College of Science and Technology
Temple University, Philadelphia PA, USA.