Saving data in PLC - possible?

[flyers]

http://www.wonderware.com/products/insql/

 

[flyers]

Marc : The one Wonderware SCADA will control 30 treatment plants, each plant has ard 100 pts to log. So, I thinki something like 3000 pts for INSQL is required. It's the hardware (WW workstation) not realible, 2 workstation down at the same time!

n_lev : Thank you for your advice, I'll talk to them, but before that I'd like to gather more info here and there so that I know what to talk/ask

JohnW : Your idea is to put a local workstation at each treatment plant to backup the data when the main redundant SCADA workstations are down?

Tom : As of now, AB still do not develop any external memory module which we can use for data logging, right?

Gerry: Thank you for your link, i'll look at it. You have any idea what's the price range for these PLC? Something like AB Price?

 

[Marc]

Flyers,

Replace the hardware for starters. If for some reason your PCs are unreliable, get new ones. They are plenty cheap enough.

Also if you need to pull in 3k points, just bump up to a higher version of InSql. I think INsql enterprise can do 150,000 tags. It's all in what you need for your application. Give your local wonderware distributer a call for pricing chemes on InSQL.

Good luck and let us know how you make out.

Marc

 

[brett93304]

One of the companies I do work for has been down this road many times. They have hundreds of PLC's in remote locations and must maintain good records by government mandate.

To accomplish this each PLC is set up with a DATA QUEUE.

Each "Event is logged with a date and time stamp and stored when the SCADA system retrieves the information the QUEUE is cleared.

Depending of how critical the information is some PLC's will shut down if the QUEUE gets full and some will over write the oldest Information.

Never hang hat on always having good Communication.

 

[Tom Jenkins]

"As of now, AB still do not develop any external memory module which we can use for data logging, right?"

Not in the PLC. Some of the PanelView Plus units have the ability to log data to a memory card. I don't know the details for transferring this to a PC, but your local distributor may.

 

[consys]

These guys have a plc that can log data:

http://www.controlmicrosystems.com/index.html

I don't know if they will be able to log as much as you are asking, but you can check it out. I have never used them. I have seen a demo earlier this year where if the SCADA and PLC are disconnected the PLC keeps saving variables. Then when the SCADA is plugged back in it receives all of the saved values. I also don't know if this feature will work with your existing SCADA, or if you need to use theirs.

Most likely what you saw a demo of was their "SCADAPak" RTU's these typically are set up to use DNP3 protocol. This protocol is used extensively in Water Treatement etc to do exactly that. The data is timestamped in the RTU and then when the SCADA connects it can download the timestamped data all at once. I have seen their demo also (actually did their training course too) With their SCADA system (ClearSCADA) it handles the backfilling of trend data very nicely. I have also seen a Citect SCADA system where the data from remote stations was retrieved in a similar fashion. They also managed to "backfill" the trend data but in the Citect installation this was achieved by the Integrators writing the functions is Cicode, where in the ClearSCADA case it just works like that out of the box.

 

[flyers]

Marc: OK, thank you for your advise, i think that's the cheapest resort.

brett93304: Data Queue is software or hardware? Can you please explain more? Shutdown PLC? Means the entire water treatment plant will not be running already! Thank you.

Tom: Yeah, I did check out the PV+ as well. Still figuring how to transfer the data to SCADA

consys: I've no experience in RTU, I'd like to ask what's the price range comparing RTU & PLC-5 (AB) with the same amount of IO? Which one is more expensive?

 

[consys]

I don't know exact pricing but I would GUESS that RTU's would fall soewhere between the low end PLC's (SLC's etc) and tyhe High end (ControlLogix etc) probably very similar in price to PLC5. best way to find out for for sure would be to check there web-site for a local agaent and ask.

 

[flyers]

I don't know exact pricing but I would GUESS that RTU's would fall soewhere between the low end PLC's (SLC's etc) and tyhe High end (ControlLogix etc) probably very similar in price to PLC5. best way to find out for for sure would be to check there web-site for a local agaent and ask.

OK, thank you, i'll check with them.

 

[consys]

I'm sure there are lot's more but the ones that spring to mind (for me) are Control Microsystems (originally posted by Gerry M) another couple you could try (I don't know their website details though) are Sixnet and Kingfisher.