On Sunday 18 November 2018 14:42:45 andy pugh wrote: > On Sun, 18 Nov 2018 at 19:33, Gene Heskett <[email protected]> wrote: > > i A 5i25 simply doesn't have enough pins. So $200 in a > > 7i90HD and 7i42TA's is next, or some other means of expanding the > > 5i25 for stuff thats not exactly real time bound > > This is a stepper machine?
Yes. But a pdm spindle setup on the 5i25's p3. What firmware should I program the 5i25 with? The pdf I've pulled and printed doesn't say what the D version is, but I'm assuming it means differential inputs are available. I am not impressed by the use of opto's because of their speed limits, and in the circuitry I have working now, the opto's in the Sainsmart BoB's I am using now, have been surgically bypassed because the 1000 line encoder now on the motor, can only function up to about 200 spindle revs, and the spindle can do right at 3000 in high gear. Ditto in the old BoB's I started out with that had opto's in the outputs, I had to bypass the one in the PDM output pin, due to the extreme nonlinear problems it caused, but the Sainsmart BoB's don't have optos in the output pin paths. I am assuming that there is a firmware for the 5i25 that treats P3 exactly as it is working now, while driving a 7I76 from the p2 connector? No, its a 7i76 on both connectors, so I'd need two of the 7i76's, which will replace the current BoB's. That brings it to over $200. I think I'll cross that bridge when and if I ever get there. It would be more compact than the 7i90+3 7i42TA's, which would get me 72 gpio's for a similar price. > How about the popular 7i76? lots of IO pins > + stepper outputs and a spindle encoder / VFD output. Don't need the vfd for this machine, one of Jom's PWM-Servo drivers is ideal for the OEM PMDC motor. With much faster control, 3000 revs to 3000 in the other direction is well under 1 second with this setup. Plus my shop made psu probably gets 2 hp surges out of a 1 hp nameplate motor. So I'll still need a pdm source for speed control. One w/o any opto's in that signal path. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
