Data Collection

Hey all,

I'm looking for some advice on setting up a data collection system. The plant I'm working in has about 30 SLC 5/04, on 4 seperate DH+ networks.

Currently we have a CLX Gateway with 2 DHRIO and 1 ENBT card to allow our SCADA system to log data.

The problem with our setup is that the SCADA system logs from each SLC individually (for ex, production data from a press line, from the press slc) and is subject to the data being unavailable due to LOTO procedures.

One idea I have is to put a CLX processor into the gateway and have it poll the SLCs on a regular basis (every 10 minutes or so, depending on the process) and store all the data in a central place. This way if a SLC is powered down for any reason the most recent data (give or take 10 minutes) is available.

Is this a standard practice when dealing with data logging and requiring machinery to be locked out? Is there a downside to this method?

The method you are describing is a data collector or data concentrator.


Yes this is a common practice if so desired. Advantage is that the scada system only communicates to a central processor rather than individual controllers.

Considerations:
1. All data transferred should be in continuous block of data. Consider standardizing your methodology.
2. Review throughput - especially considering that you are on DH+.
3. How to handle commands and setpoints from the Scada system.


There are more considerations, but this should get you in the frame of mind for developing a data concentrator.

Would this work??

Hey Christoff84,

We use a trend historian package call TendLink, made by Canary Labs. It is OPC compliant as we have it trend data from our SCADA package(Citect). In our case we store data for 30 days at a time. Maybe worth looking into, I don't believe it is too expensive.

Hope this helps,

Andrew

If you want to go the 'budget' route, have RS Linx poll the SLCs and dump the info into Excel or SQL. You MUST have at least OEM or Pro to do the OPC thing.

Another option is Rockwell RSSQL which it tailor-made for grabbing data from multiple AB PLCs and dropping it into DBs. It can poll periodically or on demand, plus return null values if there is no data.

The small RSSQL license is about $1200.

Right now we do use Iconics Genesis32 SCADA package to poll and store the data, along with Kepware's OPC server. It may just be my lack of knowledge about it (I inherited it without any training/documentation on it) but what is setup is we poll the PLCs at shift change for the production information, then send out a report. If a PLC is off at shift change, the data is gone.

Iconics is pretty old.

It may be worth looking at putting something a little more modern and flexible alongside as a 'backup' so if the regular system doesnt grab the data you can pull up the backup data from the newer system.
I dont know if Iconics supports OPC or DDE/ODBC otherwise you could actually make it back-fill from the sql or excel data in case a direct poll fails.

*edit* I Googled Iconics and it seems it supports OPC so you should be good to go. I guess if your inclined you could make the SCADA poll more often and only poll if it recieves a 'healthy' signal from the PLC.

If you already have a historian, use it to collect real time data. Then at a particular time, poll the historian for the relevant data.