Peter C. Wallace wrote: > On Fri, 30 Mar 2012, Jon Elson wrote: > >> >> Resolvers are not supported by LinuxCNC at all, as far as I know. They >> are handled by several vendor's adapters that produce what appears to be >> a traditional quadrature encoder signal, that is then handled as if it >> were a regular encoder. >> >> >> > > Our resolver interface doesn't actually emulate a quadrature counter at all, > but rather uses a A-D daughtercard followed by a standard resolver-->digital > tracking filter implemented in the FPGA. > > The LinuxCNC driver simply reads 32 bit parallel (absolute) position and > velocity registers from the FPGA. To make this more compatible with LinuxCNCs > "incremental encoder" centric feedback interface, index and simulated encoder > count outputs are created in the driver. > > > OK, that makes it sort of an absolute encoder, which I guess is available at the HAL level, good for brushless motor control. But, LinuxCNC really doesn't know the difference, and I guess that is what I was trying to point out. LinuxCNC doesn't really NEED to know about absolute encoder devices, anyway, for the basic motion control.
Jon ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
