On Saturday 16 February 2013 13:23:37 Andy Pugh did opine: > On 16 Feb 2013, at 14:35, Tomaz T. <[email protected]> wrote: > > Now what I want is only to connect this with RPM display in pyvcp. > > Net spindle-cmd pyvcp......
Thanks Andy, but that will probably need sent through a scale module to calibrate, and lacking the feedback path, will at best be a SWAG that will not show slowing vs loading. Adequate for surface speed calcs though. His use of the C6 brings up a question in my mind as to "how is the 0-10 volts from the C6 actually coupled into the VFD?" In my lathes lashup I found that a direct connection to the pot arm terminal as the C6 docs show, gave an extremely non-linear control that no amount of faffing about with pid terms made satisfactory, but it was made quite linear, enough that a pid module could cope with it, by inserting a 10k resistor between the C6's output and the pot arm terminal of the motor controller. The OP might want to test that as it might improve the accuracy of the tach dials SWAG quite a bit. The voltage drop across that 10k was, in my case, only a millivolt or so, but it made a huge difference in the control characteristics. I might also add that the C6, if part of a feedback loop, is call a surveyor and set stakes slow device, so those 2 10 uf electrolytic can caps were replaced with .1 uf mylars in mine. One is in the analog out, adjacent to the terminals, the other is in the charge pump detector that runs the relays, time lag there is a huge problem for the motor controller in a mini-lathe. It sees any speed sig as an error if the relay is slow. His vfd may, or may not have similar don't even power up if the speed isn't zero logic. Just a thought. BTDT :) Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> They are ill discoverers that think there is no land, when they can see nothing but sea. -- Francis Bacon I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials, tech docs, whitepapers, evaluation guides, and opinion stories. Check out the most recent posts - join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
