PTO - where to start

[LURBY 1]

I would like to use a ML1200 to drive an Ultra 3000 servo drive/motor using PTO I have found instructions for the PTO function file for the PLC. That seems straight forward. I have found an interconnect diagram for connecting the PLC to the servo drive. Also straight forward. How about the set up for the Ultra 3000? I have searched the manuals for the drive and for Ultraware and it doesn't mention PTO anywhere!! What mode do I put the drive in? Analog position? What is the "pulse" that the PLC is sending out? Is the "output frequency" value set in the function file of the PLC related to the speed that I want the motor to turn and if so how is it related? Thanks for your help Chuck

[Ken Roach 194]

Pulse Train Output as a motion control method historically comes from stepper motor control: you would send a pulse, and the stepper would move a step. The faster you sent pulses, the faster the stepper motor turned. Many servo controllers emulate that technique: in the Ultra 3000 it's called "Follower: Pulse/Direction" Operation Mode. There is an excellent diagram showing how the MicroLogix 1500 BXB base can be wired to the Ultra 3000's step inputs, in RA Knowledgebase Answer ID # 27781. The MicroLogix 1200 ought to be similar. Another good basic principles document is in the RA Literature Library, describing the basics of how the PTO function is used to do motion control. The document is for the Ultra1500 motion controller, but the principles are the same. http://literature.rockwellautomation.com/idc/groups/literature/documents/at/2092-at001_-en-p.pdf