Ethernet/IP Nodes 1756-L71

[Zlinger]

How many Ethernet/IP nodes can you have on a 1756-L71 processor? The AB catalog shows "N/A" for the number of nodes and 500 for connections. The L81, for example, shows 60 nodes and N/A for connections.

I have a customer with a lot of VFDs and remote I/O on an L71, and I am wondering how much more I can add.

Thanks.

 

[Ken Roach]

The number of nodes supported on the network will depend on the Ethernet module you add to it; an ENBT, or EN2T, or EN3T. You can also add multiple Ethernet modules, or ControlNet modules.

The number of Connections are the number of I/O devices the controller can support.

You also have to consider the performance you will get out of a module; the faster you ask for data, the harder the module has to work. You might get a 1756-EN2T to run all 128 possible Ethernet nodes if they're at 20 ms RPI, but not at 5 ms.

I've done a 1756-L71 system with 110 I/O connections through a single 1756-EN2T at 10 ms and it ran well.


The 1756-L8x controller has the Ethernet port built into the CPU, so that's probably why they list the number of "nodes" directly.

 

[Zlinger]

Got it. Thank you very much.

 

[Ken Roach]

There are some capacity estimation tools, and this sort of thing is a great question to get your local RA sales office involved in.

Good luck !