RA -Modbus TCP AOI - number of transactions

[frandESS]

Dear Forumers

I'm developing an ESS project with Compact Logix L36ERM and using the MBTCP Client AOI from Rockwell.

I'm using 4 AOI blocks for one IP adress/client. FC's used is 1/3/15/16.
When running one instance, no failures occur.

When running more than 1 AOI block enabled i get series of strange socket errors and believe i overload (not wait enough time until next poll) Error is 16#00ff that is a close socket message.

How can timings and waiting time be managed?

 

[Contr_Conn]

Without a Wireshark trace, I suspect that your Modbus TCP Server device can’t handle multiple TCP connections. As a result you have only one AOI connected.
If you need more than 5 transactions, then you can simply change the Ref_trasactions array size, however this will slow down processing because all transactions processed sequentially and it takes more than one scan to process a transaction. You may need to increase the default poll to 2000 or even higher.
There is another way to manage transactions dynamically:
Once transaction is done, you disable it, put new addresses and FNs and then enable it again.

 

[Contr_Conn]

I also see that first and second AIOs are sharing the same Modbus Data array. Is this intentional?
Is there a chance that you did not use Rung Import process for all AOIs, and used Copy/Paste?
Can you post ACD? Or can you export these 4 rungs and post these here?

 

[frandESS]

Dear Contr_Conn,

Thank you so much for your response.

You mention something that made me think, added a few more IP addresses in the slave device, same IP adresse since Slave can have up to 6 masters. (Its a ABB RTU540)

That solved it all, and also thank you big time for seeing my experimental mistake of dropping wrong tag on the data output.

I always import this AOI's

Anyways as you see, its kind of messy in writing FC15, i have to take them one by one instead of using a range - really dont know why its like that (checked in RTU and signals is declared as FC15) - taking them single is although working fine.

FC1 and FC3 is fine reading in bulk series.

3 screendumps attached


Again - big thanks