Thanks again for the suggestions. I feel like I am making headway. However, I can't seem to figure out how to set one of the Stepgens to velocity mode since they are all created together via some pru_generic.bin file. Is there a way to pass this argument to this bin file or is there a way to bypass the bin file and just create the stepgen on the fly?
On Sunday, December 29, 2013, Charles Steinkuehler wrote: > On 12/29/2013 11:30 AM, Peter C. Wallace wrote: > > On Sun, 29 Dec 2013, Josiah Morgan wrote: > > > >> Date: Sun, 29 Dec 2013 11:07:53 -0600 > >> From: Josiah Morgan <[email protected] <javascript:;>> > >> Reply-To: "Enhanced Machine Controller (EMC)" > >> <[email protected] <javascript:;>> > >> To: "Enhanced Machine Controller (EMC)" < > [email protected] <javascript:;>> > >> Subject: Re: [Emc-users] linuxCNC BBB capeless > >> > >> Charles, > >> Thanks again for the help. > >> Reading the manual for the vfd, it looks like the input is a frequency > >> pulse train rather than pwm to control spindle speed. Is there a simple > >> way to generate a variable frequency pulse to control spindle speed > rather > >> than using the pulse width modulation? > >> Thanks > > > > If the PRU stepgen is like most of the LinuxCNC stepgens, you should be > able > > to use a stepgen in velocity mode as a rate generator for the spindle > > Yes, the PRU stepgens will run in velocity mode, which is a good way to > get a programmable frequency generator. The only caveat is your pulse > width will be fixed so the duty cycle will change with frequency. If > that is OK with your VFD you're all set. If not, I'll probably have to > code up a frequency generator task for the PRU, unless the required > frequency is low enough (below 200-300 Hz or so) you can generate it in > the 1 KHz servo thread using the HAL software frequency generator. > > -- > Charles Steinkuehler > [email protected] <javascript:;> > > -- Josiah Morgan, P.E. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
