My first CompactLogix motion project

[technolog]

My boss has just told me I'm doing the software for a motion project. It'll be my first motion project save for some experience gained on a project that never got completed about 15 years ago.

The parts list is something of a fait accompli. The PLC is a 1769-L27ERM (I think, although it could be different - it definitely has the M in the part# for integrated motion). There are (6) Emerson Epsilon EP-P servo drives and (6) Emerson NT servo motors. I believe the plan is to use Ethernet/IP to control the axes, although to be honest, at the moment I'm pretty clueless as to how the machine should work or even what it does.

My initial reading of the PLC manuals leaves me with the impression that the integrated motion control over Ethernet/IP offered by the PLC is only possible when used in conjunction with AB Kinetix drives? Can anyone shed any light? Does this preclude me from using this controller with these drives and motors? If not, would I need extra hardware such as high speed counter cards and analog output cards?

Also, does anyone have any motion 101 resources they can point me at.

I have a feeling I'm going to be leaning heavily on this community over the next few weeks - please bear with me when I ask the inevitable stupid questions.

 

[Ken Roach]

Welcome to the Forum !

the integrated motion control over Ethernet/IP offered by the PLC is only possible when used in conjunction with AB Kinetix drives?

Exactly correct. You don't need, and cannot use, the motion control instruction set of the CompactLogix if you're not using Rockwell Automation Kinetix servos.

It's not impossible to use Emerson Epison EP-P programmable servo controllers in conjunction with CompactLogix, communicating between the two platforms over the EtherNet/IP network.

But it's going to be more effort and complexity than using the Rockwell controllers, which are entirely configured and controlled from within the same Studio 5000 software as the discrete PLC control functions.

You're looking at really programming two different systems; you'll be doing the motion control features in the Emerson platform, and the discrete control in the Rockwell platform, and stitching the two together over the network.

Is the hardware selection because somebody else did it then walked away, or because you're getting an unbeatable price, or because there's a feature in the Emerson motion controller that's perfect for your application ?

How many axes are you going to control ? Can you describe the basics of the machine and how the axes interact ?

 

[technolog]

Thanks for that Ken.

The revelation that the motion commands were only usable with Kinetix drives took me aback so much that I forgot that I'd already googled information on the Emerson site explaining how to setup Ethernet/IP comms between Epsilon-EP drives and the Logix platform, so I should have known it was possible to use the combo of Logix PLCs and Epsilon drives.

Now I need to google how to use the MSG instruction and interfacing to the Epsilon. It's going to be a voyage of discovery.