CODESYS Shared I/O Question

[Beno]

Perhaps it’s a good time to review your thoughts from November 2021…

Sharing IO between controllers

Years ago I asked a more experienced SNAP PAC designer if the IO of a SNAP-PAC-R2 running a strategy could be added as IO on a different strategy on a different controller. I was told this cannot be done. I was recently asked the same question and initially responded the same, but decided to look for the reason this is the case and after looking through user guides and other documentation, I have come up empty. Can IO be added to more than one controller?

The whole thread is worth a re-read.
I asked @greichert if Codesys had something like the generic MMP IO device, and he said he’d think it over. But the core principle remains: You can have as many controllers accessing the I/O as you like.
The key to remember is that the last I/O configuration sent / downloaded ‘wins’.

Same with PAC Control and groov Manage. We have people that setup their I/O via groov Manage in a web browser and then wonder where it all went when they download PAC Control.
Some change the PAC Control config via groov Manage and it works fine for months, then the controller power cycles and their groov Manage changes are overwritten, but it was so long ago, that they can’t figure out what changes they had made via the web browser.

The generic MMP device is just a way to try to make it read-only and save a bit of that hassle, but you don’t need it. It all comes down to documentation and teamwork (if you have more than one person working on your control system). Module per control system, entire I/O, or read-only, it’s your call.