Roger wrote: > > Jon, > If you start with a blank slate your Universal PWM is a good cost effective > solution that simplifies hardware and software setup and provides for Opto22 > relays. In my case though I already have a Mesa card (won at Cardinal raffle), > 50 pin breakout panels and I installed solid state relays for spindle, coolant > and brake when I converted the machine to Mach3/Gecko's. The machine also has > a > safe, hardware based E-stop circuit. > > In theory all I need to do to upgrade to your AMP's is to figure out how to > wire > your PWM AMP's and existing encoders to the Mesa, configure the PWM Hostmot2 > parameters and pass the machine's drive enable signal from the mill's E-Stop > circuit back to EMC. > OK, this shouldn't be a big deal. The servo amps have optocouplers that can be put in series in the E-stop chain, so that any amp that faults will cause an e-stop. The amps run off a +12 V logic supply that needs to have its minus terminal common to the motor power supply. You need to supply +12 V to the enable terminal to enable the amps, such as with an out-of-estop SSR. The PWM and direction inputs are opto-isolated and can be run from a 5 V logic output. No current in the PWM otpo = no current to the motor. The amps are designed for a 50 KHz PWM signal, but could run at lower frequency of needed. That's all there is to it.
Oh, yeah, there's one more detail. The DC (brush) version of these amps needs one short pulse in each direction after enabling, to reset the shutdown logic in the FET driver chips. The AC (brushless) amp does this internally. There is a "bootstrap" HAL pin in my driver to do this, I'm not sure if the Mesa driver has a similar function. Jon ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
