"Device on-line and has connections in the established state" -- In other words no issues seen on the main network/DNB side of things. This jibes with the DNB displaying A#01 -- that's what I'd expect to see on a healthy network. Doesn't rule out that there are scrolling faults not present in the photo, but from what can be seen everything in the main network is good.
3 - starts green, changes to flashing red after about 20 seconds
As mentioned, flashing red points to issues with the adapter connecting through the backplane to the individual card(s).
5 - flashing green (plus on Output cards all outputs flash with that LED)
This is interesting, I somehow thought you had said they were flashing
red (upon checking you didn't specify color, mea culpa) -- flashing green indicates 'Device needs commissioning due to configuration missing, incomplete, or incorrect.'
In other words, things keep pointing back to the adapter scanlists not matching what is physically seen.
As for Node 20 partially flashing
Card 1 - random flashing of LED 5, mostly solid green
Card 2 - random flashing of 5 but independent of card 1 solid or flashing & rarely flashing at same time card 1 is flashing
Cards 3, 4 - solid green always
Cards 5, 6, 7 - flashing #5 green always
Solid green on 3 and 4 tells us that the scanlist exists and has them configured. With that, my armchair diagnosis is that there's issues with the backplane and/or individual modules. (The intermittent flashes of cards 1 & 2 make me think backplane specifically).
You said the individual modules were re-seated -- just the modules, or the TBS backplane as well?
One thing is both these nodes went down suddenly together, so it is highly probable that a single issue is at fault here, not 2 separate faults with the 2 nodes happened to pop up at the same time.
I agree that this is suspect, and a reason to initially look at the main network. No further evidence that I've seen points that way though.
The -DNB does have the display, but I didn't record it and the photo has it showing "A#01"
Off-hand that's normal for a running module, if there are other things scrolling it'd be worth finding out.
I did get the 3 DNT files this morning, zipped & attached.
Everything looks normal here.
As for vibration no moving hydraulic cylinder here - these are mounted directly on a 600 ton stamping press that creates a 6.5 on the Richter scale.
*wince* In my experience the 1734 backplane is not particularly solid and long-term vibration
will cause issues, perhaps requiring replacement of parts of the TBS backplane and/or individual modules.
Note that if it is indeed the backplane at fault, switching to Ethernet won't do anything to resolve the root issue, just make it easier to troubleshoot in future.