Studio 5000 Motion Groups

I am working on a project using the 350 Kinetix servo controllers. After creating and axis for each controller the instructions want me to create a motion group. What are motion groups for? Why must I use them? What is the advantage?

I thought after I created my axis I would be able to use the axis.

Thanks.

For one thing, unless you create a motion group, you cannot schedule your axis. It is the motion group that allows you to set the update rates for your axis. More, you can clear all faults on all axis in the motion group at one time, as well as specify how the processor responds to faults. Faults on a motion group can be either Non-Major (doesn't halt CPU), or Major (does halt CPU).


Also, the motion group allows you to logically organize your axis; there is always the possibility of having several, unrelated motion groups.

Thank you for your input. I am trying sort through the massive amount of information for the answers I need. It becomes such a lengthy process that I sometimes post questions here before I know enough to ask the question intelligently.

I am finding out that motion groups are the key to coordinated motion, which is something I want to use on this project.

I think you have just answered your original question when stating "...coordinated motion..."
Obviously, without "grouping" the system's configured axii, they are not going to to share with each other any of their parameters/properties and the motion controller will treat them as separate entities.

I have six axis in this system. I want to do two groups of three for my coordinated motion. However, the system will not allow me to create more than one motion group. Can anyone tell me why? Do I have something set wrong?

What processor are you using?

1769-L33ERM CompactLogix.

Any Logix class CPU supports only one Motion Group due to single Motion Task layer (Coarse Update Rate).

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/40613 (by the way, the posted link is broken...Go figures...)

I know that the RSL5K/S5000 project tree folder dedicated to Motion states Motion Groups, however, there is only one allowed Motion Group per Logix controller.
Segregation between axii could be accomplished via separate SERCOS networks.
I believe the Motion Group plural description is dedicated to a future feature which will implement multiple motion "threads" within Logix functional firmware.

That explains it. Thank you.