Adding Flex I/O to Studio 5000 Project

I am adding some Flex I/O ethernet nodes to an existing project at a plant.


I've already set my IP addresses. And they show up with my IP scanner.


I have 2 16pt digital input modules and 2 16pt digital output modules installed on my 1794-AENT Ethernet Adapter.



I am unsure about what to select for Rack Connection and Chassis Size.


My options for Chassis size are from 4 to 8.


Is it as easy as selecting 4 for the number of modules that I have connected to my node? If so, can I use a higher number to reserve space to add modules later?



Also, any other insights are welcome.

It is as easy as stating how many you have connected....
If you put more in as an advance, will it give you a warning/error? not sure...

And you can add more afterwards if you require new modules, and the tags get added on automatically.

I've just started a Control Logix 5580 (L83e) / Flex 5000 system. It's a retrofit/replacement for an OLD ABB Taylor MOD300 DCS. Took all of the existing field junction boxes (16 of them) and ran the appropriate ethernet, additional power circuits and installed Flex5000 in each. They're snug, but not irresponsibly so... The Control Logix is located close by in a re-purposed Cabinet with supporting power/network equipment.

Supply constraints made it impossible to obtain a 1756-EN4TR, so I selected a 1756-EN2TR placed in Slot1 of the PLC to connect to Flex5000 IO, not overly concerned about loss of bandwidth having to go down to 100MB speeds.

I have 8 5094-AENTR modules; each have anywhere from 4 to 6 io modules. It's a very distributed setup. I have all of the 5094-AENTRs running at 100MB. So the single 1756-EN2TR and the 8 5094-AENTRs are connected to a Stratix 5700 Switch that isn't uplinked to anything... Again the 5094-AENTRs are adequate because this project will NEVER have any 5094 backplanes with more than 4 to 6 io modules (well below the limit of 8) and most of those io modules are scarcely populated.

When I set the 5094s up in Designer Studio I determined the Chassis side by adding up all IO modules and adding in the adapter module as well... So those setups with 4 IO Modules would have a Chassis size of 5, with the adapter module as slot 0 and the rest of the IO modules numbered sequentially. I even had to use the 5094-CE05 cables to extend the backbone between cabinet pairs (all 8 drops consist of 2 parallel junction boxes located inches apart... 1 for the digital io and 1 for the analog io.) that cable is just a physical backbone extender between the two boxes, and doesn't change chassis/slot configurations for your Flex5000 backplanes..

Anyway, hope my real life, real-time, example helps.

BTW, really struggling with supply constraints... barely getting things in fast enough to keep up with commissioning... Blessed that the project allows me to commission it in 6 phases... Juggling around parts as they come in to re-align with phases get done first...