> If not, any suggestions for better accuracy with fewer points?
> I've already manipulated the integration method and gotten large
> improvements over the 2nd order trapezoidal (I'm on a 4th order Gear at
> the
> moment).

In your case you would like to limit the "maxstep" to a smaller value to
get better accuracy, but few points only.  Did I understand you correctly?

Yes. That was the immediate solution that sprang to mind.

I do not know enough about the simultaor internals to do more than speculate, but I suspect my problem originates from the fact that I'm using ideal relays. I am guessing that large maxstep values result in the simulator missing the actual close/open time and instead uses the nearest maxstep that is near the close/open event, but that the discrepency does not cause convergence problems so the simulator does not drop to a smaller step value. If this theory is correct, a better solution to the problem would be for the simulator to attempt to locate the actual relay / switch open/close time. This would be done as follows
1. Note current time
2. Calculate next timestep
3. If a relay / switch changes state during the timestep, use a binary search to get more accuracy on the switching point
It's possible that the simulator is doing some form of this, but if it is, I do not understand why I seem to need a smaller "maxstep" value.

Thanks for your time Stefan,