RogerN wrote: > For the 850 RPM gear range, I need 2-3 second decel, for the 2800 RPM, I > need around 8 second decel. I could use a drive input to select between > motor 1 and motor 2 and have different decel times for the motors. > > Thanks > Roger Neal
Are you sure you really need to close the speed loop? Or would it be sufficient to simply send the appropriate command to the VFD? "Appropriate" means that it has been corrected for the gear ratio for whatever gear you are in at the moment. If you can mount a switch to your machine that is actuated in one gear (ideal), or if you are willing to click a GUI button to tell the system what gear you are in, its not that difficult in HAL to generate two speed commands, one for each gear, and route the appropriate one to the DAC and then to the VFD. That's what we do for the Mazak at the CNC workshop, but we went one step farther there - we have classicladder logic that actually does the gear change sequence. The Mazak has hydraulics to shift the gears, and prox switches to tell what position the shifter is in. The HAL/Ladder config we have automatically slows the motor to 15 RPM, then shifts to neutral, shifts into the new gear, and accels to the final speed. Regards, John Kasunich ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
