How many datapoints do you monitor.

Hi all.

This is my first post on the forum so be kind to me. I work in a factory environment where we have around 60 monitored PLC's (Mainly AB), and of these, around 500 tags are logged to a historian, most at either 1sec intervals or delta.

So, my question is..

Is this a lot of monitored tags compared to other industries out there (PLC's to tag ratio). Could some of you give me an idea of how many PLC tags are historized at your company? (I don't need to know which company you work for, I'm not that nosey ;-) This will give me an idea of where we sit in the scale of it all.

Cheers.

5000 and some change. 11 years ago, I'm sure it has grown since then.

500 would be a small installation as I'm sure you will see in the coming posts.

Around 100 PLC's.

Process part of the plant we have several thousand data points being logged continuously. Temperatures, states, stepnr's, etc.
These are logged in various ways, some in WinCC, some in Historian.

Packaging part of the plant we have about 2000 logged on change.
These are logged to a csv-file, then ported to MySQL. The csv is limited in size, the SQL not so much.
These are mostly parameters, some are states/stepnr's. We set it up because sparkies were lying to us about what they changed during their 'troubleshooting'.
In the packaging part we do the same for alarms on our fillers. These are about 15000 total.

Currently no logging on our Rockwell systems, haven't had the time yet to tinker with logging on those.

We have around 150 PLC's at the last count and log several thousand data points. QC and traceability data is logged to an SQL Server machine and kept indefinitely. loop analysis and tuning data is logged by a seperate dedicated system and general data from our RSView SCADA system including process values and running currents for all motors etc. is logged and kept for 30days to limit the required storage space. This works for us in a large food processing plant.
Jeebs. - I was in Leuven for the first time a couple of months ago. Nice town but what is the story behind the big dead fly.

Apparently it's a scarab beetle.
Signifies beauty, science and knowledge.
Was made to commemorate the 575th .... b-day? of Leuven.
Artist was given complete freedom, only told it must be big, memorable and get people talking about it.
He certainly succeeded in that regard.

Ive done some large ones, largest being around 300k tags. The majority of them being 1 hour polling cycle. Ive done a few more around 75k. Largest amount of devices polled was a little over 2000.

BegaCheese said:

we have around 60 monitored PLC's (Mainly AB), and of these, around 500 tags are logged to a historian, most at either 1sec intervals or delta.
Cheers.

Click to expand...

Is that 500 tags total? Or, 500 tags per PLC = 30,000 tags?


500 tags on Ethernet is small. On a serial, DH+ or RIO network then 500 tags/second makes a big difference.

Thats 500 historized tags total (doesn't include tags used by HMI's etc). Most go direct ethernet to the PLC, some go ethernet to a gateway PLC and then DH+ to the actual PLC and a few then go from DH+ to 485 (thats for the PLC's we got off Noah).

I'd be careful about how fast/often you poll tags from the DH+ and 485 networks.
Just something to keep in mind as you are connecting from Ethernet; easy to forget or not notice that the bottleneck is on the PLC side network.