On 11/14/2013 8:11 AM, Maximiliano Fermín Córdoba wrote: > HI > > I´m trying to modify the BeBoPr-Bridge.ini file, but I get stuck when I saw > that the steps timing config was already OK for me. (I need pulses of 1useg > and 1useg minimum distance between each other) > > The thing is that I´m seeing step pulses of 10usec width, but the config is > set to 1useg ([...] STEPLEN 1000 in nanoseconds [...]). > > Is this an issue of the minimum step pulse possible ?
By default, the PRU thread is running with a 10 uS period, so that is the minimum time any pulse can be made high or low. The 1000 nS pulse width is a *MINIMUM* time, so the pulse length will be at least that long, but possibly longer. > Also, an error come out saying : "hpg: stepgen.00.maxvel is too big for > current step timings & position-scale, clipping to max possible". Has this > something to do with my issue? This is due to trying to generate too many pulses per second. You mention a 5000 mm/s feed (which is *VERY* fast), but what is the pulse rate you are trying to generate (or the steps per mm for your machine)? With the default 10 uS PRU task period the maximum theoretical pulse rate is 50 KHz, but I wouldn't recommend going much over 30-40 KHz in actual use (or even lower, depending on your particular servo drives and their sensitivity to jitter). The 10 uS period for the PRU is a *VERY* safe value, it can easily be dialed down if you need faster step rates. Alternately, it is possible to offload a few very fast dedicated step/dir generators to the second PRU and get the task period below 1 uS, but I haven't written code for this yet. Let us know what rates you need to hit and I'll advise you on the best way to get there. -- Charles Steinkuehler char...@steinkuehler.net ------------------------------------------------------------------------------ DreamFactory - Open Source REST & JSON Services for HTML5 & Native Apps OAuth, Users, Roles, SQL, NoSQL, BLOB Storage and External API Access Free app hosting. Or install the open source package on any LAMP server. Sign up and see examples for AngularJS, jQuery, Sencha Touch and Native! http://pubads.g.doubleclick.net/gampad/clk?id=63469471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
