Hi Ray, i thought many time about changing the fpga code of the MESA card for generating step and dir for steppers. It should be possible by keeping the interface to EMC2 and driving the steppers like servo´s (from EMC2 perspective). This would help everyone who needs to generate a high, accurate step-rate e.g. for microstepping applications. Unfortunately i´m not very familiar with VHDL but this should be no problem for someone with VHDL knowledge. So where are the guys ?!
Stefan On Thu, 2007-01-11 at 13:56 -0600, Ray Henry wrote: > Hi Eric > > I don't have my mesa card in the fast computer I used for the 71k pps > stepper tests but I tried starting up a mesa card inside a stepper_inch > setup. Since all of the mesa communication is in the servo thread it > does almost nothing to the ability of base to spit out pulses. > > Certainly changing the fpga code is the more elegant solution. > > Ray > > > On Thu, 2007-01-11 at 11:03 -0500, Eric H. Johnson wrote: > > Hi all, > > > > This is mostly in context with the Mesa M5i20 board. I have a new project > > where I need to control two micro-stepping stepper motors, as well as a > > laser. The laser takes a PWM input. I am pretty much committed to the m5i20 > > for the PWM, but at the same time need to generate 60-70Khz step and > > direction for the two stepper motors. The current configuration is for 16 > > micro-steps per step, where the stepper module accepts up to 70Khz for the > > step input, although the maximum rate I would need is more like 60Khz. > > > > What are my options? For a servo system, using a 2.54Mhz processor, I was > > able to crank up BASEPERIOD to 50Khz in a system which also used the m5i20. > > However if that resulted in over driving the PCI bus, I am not sure that > > would be apparent in a servo system. Using ordinary outputs on the m5i20, is > > it possible to generate a 50-60Khz step signal, given a sufficiently fast > > CPU? > > > > Alternatively, and I have not looked into this too much, how much would be > > involved in changing the FPGA configuration to support step and PWM outputs. > > My thought is to just slightly modify the existing m5i20 EMC configuration > > to either be able to set a bit (in the interface, i.e. RegMap) to indicate > > whether to generate PWM or Step signals on the specified output, or to have > > PWM and Step simultaneously available on separate outputs (on P3 or P4 > > connector, if something on P2 cannot be reused). > > > > Thanks, > > Eric > > > > > > > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of IT > > Join SourceForge.net's Techsay panel and you'll get the chance to share your > > opinions on IT & business topics through brief surveys - and earn cash > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > _______________________________________________ > > Emc-developers mailing list > > Emc-developers@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
