Allen Bradley Produced Tags with multiple consumers

[jakeparsons03]

I have a "Master" 5069-L306ER PLC that is going to hold 1 produced tag running out to 9 consumer PLCs. The L306ER only supports 8 ethernet connections. My question is if I only have 1 Produced tag on that PLC and set it to take in 9 consumers, does that count as 9 ethernet connections or just 1?

 

[GaryS]

Short easy answer upgrade the processor
I have run into that before and the only answer is upgrade
if you wamt to do an indrect way may work for you is have a server computer read the tag from the master and then snt it each of the other PLC's ut i don't like it

 

[RET]

Read page 11 of this document, regarding number of connections.

https://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm011_-en-p.pdf

 

[JeremyM]

Try messaging instead? It’s as reliable as your network.

 

[Ken Roach]

Rockwell tried to simplify "connection" counting with the 5069 series by documenting only the number of "EtherNet/IP Nodes" that each controller supports. A "Node" is simpler to understand: it's a device in the I/O tree under the Ethernet port in Studio 5000.

The technical data sheets don't even specify the number of "CIP Connections" anymore; you have to dig a little deeper into Selection Guides to discover the limit is 256 CIP Connections, over up to 120 TCP connections. And you have to estimate the packets/second capacity of the interface.

The 5069-L306ER supports 8 local I/O modules, and 16 EtherNet/IP "nodes".

If one of those remote PLC's is in the L306ER's I/O tree because the L306ER is Consuming a tag from it, then it definitely counts as a node.

But when the 5069-L306ER is in the I/O tree of one of those other PLCs, does that count as a Node, or just as a Connection ?

>1 produced tag running out to 9 consuming PLCs

What I have read is that the Producing controller will reserve 10 total CIP Connections: one for the Produced tag, and one for each Consumer. It will use them all if you're using Multicast, or just enough to serve the active ones if you're using Unicast.

I have never had to figure this out for certain, and the user manuals I am reading frustratingly do not answer it clearly: do CONSUMING controllers count as "Nodes", or only PRODUCING controllers that are in the I/O tree ?

I think you need to contact RA Technical Support for a clear answer.

 

[cardosocea]

If only Rockwell has ever heard of things like UDP multicasts...

 

[AlfredoQuintero]

If only Rockwell has ever heard of things like UDP multicasts...

Implicit message connections configured as multicast use UDP IP.

 

[Jim3846]

your processor tabs will show how many connections you have. I think its the memory tab of the controller display. Also, if you type in the ethernet ip of the controller, this will also show you stats and connections.

 

[Ken Roach]

Cardosocea: you can choose to use UDP multicast or UDP unicast with EtherNet/IP cyclic I/O. Produced/Consumed Tags use the same mechanism as ordinary I/O.

The difference is in how internal "connection" resources are allocated in the CompactLogix. When you're using multicast, all the multicast addresses in the pool and the data buffers to move the data there have to be both used and allocated. When using unicast, they just have to be allocated but they can be added or subtracted as the Consuming controllers come online and make requests.


Back to the original question: the CompactLogix 5380 and ControlLogix 5580 have a multicore processor and dedicate one core to communications. That gives them enough processing power to be able to basically guarantee that anything you do with X number of I/O devices will be within their capability. They decided to call the devices in the I/O tree "nodes" for the purposes of capacity calculations.

That number of supported Nodes in the I/O tree differs by model. The 5069-L306ER is the smallest-capacity member of that family of CompactLogix, and it supports 16 Nodes in the I/O tree.

Where this question gets difficult is the question of whether Produced tags count as a "Node" for the purposes of Studio 5000's capacity calculation.

I don't think that they do.

I think they still count against CIP Connections (a limit of 256) and against the packets/second capacity of the Ethernet port. But because Producing a tag doesn't require the Consumer controller to be placed in the I/O tree, I think that the software doesn't consider a Produced tag to be one or more of the "Nodes" that are checked by the software and limited by the model of controller.

I cannot be certain of that because I have never tried to do large numbers of Produced tags from a small 5380-family CompactLogix, and because the precise text of the user manuals and technical documents I have read do not specifically address Produced tags.

I think I've been spending too much time with lawyers.

 

[JeremyM]

^ Just produce/consume the biggest array of SINT you can, whenever. Max out that CIP packet, baby. You can then unpack responses into UDTs via COP and do the same thing for produced data. If you ever need it changed, it can all be done online and with new UDTs if need be.

Today I encountered a bunch of produce/consume connections dedicated to a single bool, each.

I grew pessimistic about humanity.