andy pugh wrote: > On 26 October 2013 21:09, Jon Elson <[email protected]> wrote: > >> The ABS encoders, if battery backup >> is provided, apparently put out a burst of quadrature pulses to >> revolve the apparent position to the offset from the index >> position, thereby eliminating the need to home the axis. But, >> I've never tried this with my PWM system. >> > > I can't see any reason for this not to "just work" if the power-up > sequence is correct. > Yes, that's the trick. You'd have to wait for LinuxCNC to be fully up, AFTER it zeroes the encoder counters, and then power on the encoders so they send that quadrature pulse train. It may require some control signal to the encoder to make it do this. Fanuc, of course, doesn't have any documents on ANYTHING, they are more secret than the CIA. Then, you'd have to have LinuxCNC clear all offsets in the .var file, so that the initial value in the encoder position counts are taken as the machine position at startup. This is certainly not the usual way of using LinuxCNC, but it seems like it MIGHT work without any code changes. Clearing the offsets in the .var file might be handled by a startup script.
Jon ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
