Compact Logix multiple VFD Ethernet communication

Hello Experts,

I have begun working on a new project and am specifying all the components. I am planning to use the AB compact logix platform and believe it can handle the number of I/O's I have. However, I have about 8 VFD's that need to be controlled over some communication protocol directly via the PLC and was advised to use the Ethernet protocol for this by our vendor (due to issues with DeviceNet) - is there some module which has multiple ethernet ports to facilitate this or I would have to buy multiple communication modules (like Prosoft) for this ?

If there is another better way to do this, please advise.


Thank you for your time!

No, you buy a switch.

Thank you very much JeremyM for the prompt response! Could you please point me to a P/N from a vendor that I can read up on this ? Does this have to be a Allen-Bradley or 3rd party modules works too ?

Please excuse my ignorance on the subject.

If you are using Compact Logix, make sure it can handle the number of devices you are needing to connect to.

There are versions of the CompactLogix plc with Ethernet connections built into them. These connections are capable of supporting Ethernet/IP master functionality. This will allow you to connect the drives on an Ethernet and control the drives as if they are I/O. To do this all you need is an Ethernet switch that will support the number of physical connections you are dealing with.

Keith

There are most likely several options available to you here. An Ethernet switch may be one of them, but it is not the only one.

You have not stated which VFDs you are likely to use, and whether they are all to be installed in the same enclosure as each other and/or with the CompactLogix controller. Also, is this to be an isolated cell or does it need to be capable of communicating with other cells, or the wider Industrial Network, or the Enterprise Network? Which networking architecture are you considering, if any (Linear, DLR, etc.)?

Either way, and for example...

Within a cell i.e. a local network of node devices that must communicate with each other, a PowerFlex 527 Drive provides dual Ethernet embedded switch technology to provision these drives onto either a Linear or Device Level Ring (DLR) network topology. This means they have two Ethernet ports built in. This allows these drives to communicate using Ethernet/IP directly with a Logix controller. The embedded switch technology allows them to directly manage the data that must pass in to them and through them to other nodes without the need for a centralized switch.

A PowerFlex 755 Drive can use a 20-750-ENETR option module which also provides Linear and DLR support with dual ports for direct communications with Logix controllers.

For drives, or indeed any nodes, that do not have embedded switch technology i.e. dual Ethernet ports, there is also the option of using a 1783-ETAP Ethernet/IP module for Linear and DLR support. This, similarly, provides the necessary Ethernet port count required to connect nodes in series or ring formation while supporting the Ethernet/IP communications protocol.

And so on...

A lot depends on your intended physical layout of the network, be it all in one enclosure or more dispersed.

You can, of course, also use an Ethernet switch, such as the AB Stratix line of Industrial switches, if a switch suits, but it is not the only option here. That is the point I am trying to make.

Only when you need to communicate with other segments of an Industrial Network should you really need to consider using a managed switch, such as the Stratix 8000 series. For local only communications within a cell, devices with DLR built in, the use of optional DLR communications modules, additional DLR appliances, such as the ETAP, or even unmanaged switches may suffice.

I'm sorry if I'm not advising you specifically as to what to use here. I'm more passing through and dropping off some advice to the advisers, for now...

...and hello to you to.

Regards,
George

Hey George,

I'm not sure if you were aware of something unique with the PF527, but it's a VFD that programs as a Motion Drive. Where we don't know the type of CompactLogix controling the drives, I would suggest looking at either the PowerFlex 525 or 523 with the duel port Ethernet card option instead.

Unless, of course, this applicaiton is based on a Motion layout, then just ignore me... LOL

Hi,

Quick reply...

Yes, thank you, I am aware of that fact. As we don't know which drives yet, or the nature of their intended application, I was just using an example or two of some PowerFlex drives and the various flavours they come in with regard to connectivity and the use of an Ethernet protocol. Something we do at least know is a specification here. So my examples were solely based on the fact that they provide embedded switch technology or an optional communications module. I was not making any recommendations for the use of any specific drive. Something I attempted to make clear in closing. Our friend may not even be considering AB drives here. We'll have to wait and see.

Regards,
George

Yes, exactly George. I wish there were like buttons for replys.

I have had a couple quote reqeusts from customers for 527s that didn't notice the Motion programming perspective, but were excited over the duel port Ethernet option.

For a small isolated network with 8 drives, the PLC, and a panelview, you should be able to get away with a simple unmanaged switch rated for industrial applications. If you go the AB route, the 1783-US16T is a 16 port unmanaged switch a should run you about $600.

Doing a DLR with all the drives adds a bit of redundancy to your network, but it may not be worth the added cost and complexity of using a switch and star topology. That is something you will have to decide.

Thank you very much everyone for your comments! This is all very helpful.

I learnt about the A-B Power Flex drives yesterday from our vendor and the ability to implement the ring topology using the dual Ethernet port processors; I believe George and Drives_Guy_NS are also referring to this. We haven't yet decided on which drives we will go with but will definitely consider the Power Flex drives now and our other option is ABB since we are familiar with it.

Regarding the other questions:
We are planning to have two cabinets - one for control (this will have the PLC and other I/O modules) and other for MCC (this will have the drives) with wires running between the two. This is only a local pilot plant for our internal R&D testing so I think we will not need any Industrial or Enterprise Network.

I am not really familiar with any networking architecture - Could anyone please shed some light on this ? Thanks