Powerflex 70 Speed Command

[Carl C 0]

I've set up a Powerflex70 to communicate with a L32 Compact Logix via 20-Comm-E ethernet. Every thing is working correctly except the speed command. When I send it a speed reference of 14.6 Hz (146 in the Drive:O.CommandFreq), At the Powerflex70, the drive speed command shows .6 Hz. At the same time, when I look at the drive output frequency at the plc (Drive:I.OutputFreq) it shows the 146 that I sent the drive. If I change the speed at the plc, it does change at the drive, but with no logical scaling that I am able to make work. Any thoughts?

[BobLfoot 301]

Two things off the top of my head to check.  Make sure you're configured for speed reference from ethernet, there is more than one parameter involved in getting this right as I recall.  And Two make sure you have the motor parameters configured correctly.  Current Limiting or other things can produce strange speeds.

[ElectronGuru 81]

To get the drive to respond to Logix speed reference commands, I believe you only have to change parameter 90 to the DPI port that your 20-COM card is parked in. But Bob makes a good point; if the motor name plate data is not properly entered into the appropriate parameters, the motor and drive will not respond correctly to each other. Having the current limit set to 1 amp on a 10 amp motor would definitely keep you from reaching higher speeds. Make sure your acceleration ramp rate isn't set to a bazillion seconds. These little "gotchas" can be a real pain on a new setup.

If all of the name motor plate and running characteristics are programmed properly, dig a little deeper:

When the drive is running and the motor appears to have accelerated to the steady-state speed for any given input from Logix, check parameters 209 & 210. It's a good idea to find out what the drive "thinks" it's actually doing, compared to what you want it to do. For instance, in parameter 209, if bit 8 is true, then the drive thinks it's at the desired speed.