> ... > So, this makes sure that the encoders for ALL axes are > sampled simultaneously, and then the DACs are updated > simultaneously on the next servo cycle. Thus, there is no > variable delay between encoder sampling and DAC update, it > is always equal to the servo thread period +/- the jitter at > the start of the thread, which is typically less than 10 > us. (Much less on a machine with good latency jitter numbers.) > > Jon
Even though there are jitter on servo thread this jitter make no difference, anywhere within period is equally good because signals are latched/updated by hardware at period. Ideally in a good real time operating system there should be a list of all real time processes and worst case execution time. Then these exuction times and worst case execution of a new thread is known it is possible to calculate if enough execution time will be available. It might be hard to get an exact number but an upper bound is enough. Nicklas Karlsson _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
