Small plant, eight machines, a mix of CompactLogix on the newer ones and two SLC 5/05s on the old presses. Every machine's got its own PanelView, mostly Plus 6 and Plus 7. The owner walked through last week and wants one screen in the office showing all eight, running or stopped, counts and alarms, by year end.
I'm the electrician here, not a programmer. The integrator we use says SCADA, Ignition or FactoryTalk View SE, licence and a server with it. The PanelView bloke at the distributor says stick a big Plus 7 in the office with all eight controllers in one application and be done. So I've priced both and the SCADA's four or five times the money, and nobody here has ever asked me for a report.
For eight machines, does the SCADA money ever pay for itself, or is the big Plus 7 in the office the honest answer? I'm not sure I'd know the difference in two years.
We did the big PanelView in the office thing. Eight controllers on one Plus 7, and it worked, right up until the owner asked why the count was different Tuesday. No history, no way to answer him.
I reckon you want to ask him what he'll do with the screen the first time it says something he doesn't like.
Fair. Asked him.
He said he'd want to know when it stopped and for how long. So that's history, whether he calls it that or not. He still says he doesn't want reports.
Then you have your answer, and it is not about how many machines fit on a screen. Eight on one overview panel is fine, a Plus 7 will hold the shortcuts and the SLCs will talk to it. What a panel will not do is remember. The moment anyone asks when it stopped and for how long, you need something that stores time series and alarm history, and that is a SCADA whichever badge is on it.
Buy for what the owner asked this week: eight states, counts, downtime history. Any of them does that on one licence and a small PC. The four times price is probably a full server and a client count you do not need.
Someone did a decent article on where SCADA earns its place: https://plctr.com/introduction-to-scada-systems-and-their-integration-with-plc/
Went back to the integrator with "smallest edition that logs, one PC, one client". Price came down to a bit under double the PanelView. Owner's thinking about it.
Still not sure I can sell double for "remembering".
Tell him the second PanelView he'd buy in two years costs about the same as the difference. That's how ours went.
Owner went for the small SCADA. Ignition on one PC, smallest licence the integrator could put together, one client, all eight machines, running and stopped states with a downtime history, counts, alarms in a list. He says the history in that edition covers what the owner asked for and I'm taking his word on it. Two weekends of work.
So the line for us turned out to be history, not screens. Eight machines on one overview is fine for a panel until somebody asks when it stopped and for how long. What settled it was pricing the smallest logging edition instead of the server that was in the first quote.
The two SLC 5/05s need a driver the integrator hasn't confirmed yet. If that goes sideways I'll be back.
Thanks kaim and carlh.
Come back about the SLC driver. That is the part I would check first.