Adding VFD to PLC

Hello,

I've read on some posts that to add a VFD to a PLC program you first have to download the AOI from the Rockwell website. My question is, why is that really necessary to do when you can simply a VFD module on the I/O configuration in the PLC program and control the VFD. What's the need and value to download the AOI or is it only needed to do for older PLC like Micrologix ?

Thanks

No, you can use your own logic directly with the I/O, AOI not needed. An AOI would only be used with Controllogix or Compactlogix. With a Micrologix, its just roll-your-own logic working directy with the VFD I/O.

It is not a must; it helps with concentrating the essential parameters within a structure that could be replicated across the application for multiple instances, however, adding it as a module to the I/O tree and using the hardware defined tags just like any other device will do.

Just to clarify:

An AOI (Add-On Instruction) is not the equivalent of an AOP (Add-On Profile); the latter is required for any device networked as I/O within any Logix application I/O Tree.

@jstolaruck: Does that mean that An AOI for VFD is required when on a controlLogix or CompactLogix ?

AND

@dmargineau: Does that mean that An Addon-Profile is required for VFD on both ControlLogix and CompactLogix ?

wanher3 said:

Does that mean that An Addon-Profile is required for VFD on both ControlLogix and CompactLogix ?

Click to expand...

Yes; usually AOPs are included within the RSL5K/Studio5K software install package, however, if the installed software version is older than the release of a VFD firmware then you will need to download the respective AOP from RA servers and then install it on the PC running the configuration software.

https://compatibility.rockwellautomation.com/pages/search.aspx?crumb=117&q=AOP

But I think my question still remains; why do I need to download an AOP for the VFD when I can simply go to my I/O configuration, add new module and select PowerFlex ?
what is the need for downloading this AOP ?

Just like the IO modules, the VFD has some defined parameters. They can change between different firmware revisions. So the AOP tells your program what are the parameters of your IO module (the VFD in your case)

wanher3 said:

But I think my question still remains; why do I need to download an AOP for the VFD when I can simply go to my I/O configuration, add new module and select PowerFlex ?
what is the need for downloading this AOP ?

Click to expand...

What you are selecting IS the AOP. Sometimes they need to be updated for bugs/firmware issues and you must download the new ones for the programming software to work correctly.

For example, if you install RSLogix v19 you will not be able to select a Powerflex 525 drive because they were not released when RSlogix5000 V19 was out. However, if you download the AOP, you can then add the powerflex 525 drive to your I/O tree.

You can do it with nothing but a generic ethernet ip device if you want to. Updating the drive database will give you the ability to add it from the hardware dialog and get an module interface structure with named elements that makes everything more user friendly to program. Going full AOP gives a ton of configuration software that allows you to configure the drive online/offline and download/upload from the drive. It also allows the drive config to stored on the PLC for Automatic Drive Replacement to work.

Totally worth it for the Powerflex 523 525. For the 527 you can't use them without because they use motion commands to operate.