MBTCP Client AOI on L33ER Compact Logix

[frandESS]

Hi Friends,

I have an upcoming project were I need 20 pcs of ModBus TCP Clients / AOI. to control 10 devices

I use 20 transactions to control 10 devices, however some devices have SUNSPEC registers spread all over the address range, that we need to access - there for using 10 transaction / 2 MBTCP clients(AOI) for one unit to control.

Is this high number something that should be kept on an external HW instead, such as HMS or similar Modbus extender?

Reason for have it on PLS is that it goes way quicker to just fill in the correct transactions during commissioning (some trial and error)

Update of incoming values is ok to be set to 1000mS

PLC is L33ER Compact Logix, please feel free to share your knowledge on the topic.

Would like to hear comments here

 

[Contr_Conn]

While what you are doing maybe possible, I would use an hardware gateway.
Each AOI can handle up to 5 transactions. You can change this to 10, by changing the array size, but this will require to use 2000ms polling rate.

Using multiple AOIs for the same device maybe possible, but not all devices support multiple connections from the same IP address.

You can have up to 32 AOIs per controller, but most likely you will run out pf memory on this CompactLogix or will not have a room for any application code.

 

[5618]

If I was doing that project, I would want to use a ProSoft MVI69E-MBTCP module. If you have trial and error to figure out some registers, the AOI would be good for that. Once that's figured out, I think it would be so much cleaner to have the module handle the communication and all you have to do in the PLC is unpack or repack the data for whatever you're doing with it.

 

[frandESS]

Thank you so much for all valuable input.

I'm using an L36 on this project. I actually have some spare modules -Prosoft PLX31-EIP-MBTCP or HMS-EN2MB-2

I will dive into them and see how i can utilize the leftover modules Also ordered a few ProSoft MVI69E-MBTCP

Its always dirty using leftover parts

Thanks for all input regarding the AOI.It so simple to use - but eats some memory.

 

[5618]

I haven't used that model, but the PLX31 should be about the same as using the in-chassis module. It looks like it does 10 clients, just enough for your application. Any expansion and you would have to double up devices under one client. The MVI69E does 20 clients.