[liketochill]

Wonderware historian, inductive automation ignition, and osi pi all can buffer data at a collection or edge node that it collects from a Plc and then forward it on to the central database historian when connectivity is present. Grafana might have a better web ui but they all offer some client for plotting.

I am curious in what regard nothing comes close to grafana? I am Currently paying a lot for citect and wonderware support across a couple dozen facilities.

[camtarn]

We're a bit of a weird case in that we log data at 20Hz and 100Hz for prototypes, so we need custom queries and/or aggregation to reduce that down for display. We had a good chat with Inductive earlier this year, but even they said that might be a bit much for them. Other than that, though, Ignition is literally everything we want in a single product.

[liketochill]

You are logging data in to grafana at 100 Hz from a Plc? That’s pretty quick for a plc, I’d definitely have either a tiny program or a fast periodic task to be generating new samples every 10 ms, although I’m sure there are faster PLCs out there than m340

[camtarn]

Hehe, yeah. We run B&R PLCs which are fairly beefy Atom processors under the hood.

[mhall119]

Telegraf can do this too, in a more limited capacity. It keeps an in-memory buffer of collected data points so if a write to an output fails it'll try again on the next interval without losing the data it has already collected.