Created Date: April 06,2009

Created by: bcarlton

Actually its not all that important that the DL06 be FAST while you are moving quickly. A few missed locations won't matter.

I assume you will be slowing as you approach the target. It this a two speed type function (HI - LOW -OFF) or can you vary the speed smoothly? If you can vary it smoothly (by writing a value via communications or by an analog output) then I have found a crude positioning algorithm of velocity being proportional to the square root of the distance left to be traveled works ok. You need to determine the max permitted speed and the lowest speed allowed.

Unless you can hold position under power you may have to be content with a couple of count error in the final position. Good luck.

Created Date: April 06,2009

Created by: Ryan_Poethke

bcarlton,

Thanks for your advice. I will be controlling the drives (GS1's) via RS485, so there should be no problem in writing smoothly changing values to the speed references. I'm hoping to ramp down with about 25 counts to go or so, and then creep into final position. It won't be a problem to be off a count or two in either direction.

As always, thanks for your help.

Sincerely,

Ryan Poethke

Created Date: April 05,2009

Created by: Ryan_Poethke

Hi All,

I'm planning to use a 10-bit, 720 pulse absolute encoder to control a turntable. The turntable only has to rotate at 3 RPM, but I'm still worried about the PLC (a DL-06) catching all the transitions. 3 RPM is pretty slow, but I need to be able to detect and perform operations based on a single count.

Do I have anything to worry about? How much do I need to worry about scan time? I know these are pretty general questions and that my "mileage may vary, " but any advice would be very helpful.

Thanks,

Ryan Poethke