Your math looks correct to me. The maximum encoder count rate for the 7i33 is 10 MHz using the RS-422 differential inputs. I do not know the maximum encoder counting frequency of the 7i43 because that is dependent on the FPGA pattern loaded, but I suspect that it is also greater than 10 MHz.
This setup would allow travel rates of up to 135.6 inches per second, or 8138 inches per minute. At this speed your screws would be spinning at over 40,000 RPM, so I am pretty sure you would be limited by mechanics, not by the performance of the MESA hardware. It is also possible that your encoders have an upper frequency limit below 10 MHz and could limit the travel speed, but I still expect this limitation would come into play long after your screws give up the ghost due to whipping motion. Steve Stallings > -----Original Message----- > From: Bruce Klawiter [mailto:[email protected]] > Sent: Sunday, February 03, 2013 2:00 AM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] Calculating encoder counts per inch & > can it be to much > > Not sure I am doing this right, trying to figure out what > encoders to buy. > Will mount encoder on end of motor, the motor pulley is 10 > teeth, screw pulley 18 teeth, screw pitch .200, differential > 2048 CPR encoder. > My calculation: 2048 X 4 X 1.8 X 5 = 73728 counts per inch? > > Can I have to little or to may pulses, I am thinking a 1024 > or 2048 CPR differential encoder and using Mesa 7i43 and 7i33 cards. > > Your help is appreciated, > Bruce ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_jan _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
