Hello everybody!!

We’re trying to develop an SCADA system for energy plants, but we’re a totally newbies in PLC programming.

What we need is a device that, every such period of time, can read 10 analogic inputs values (voltage, current, temperature...) and store them in its internal memory, so the PLC must have a real time clock to correctly store the time the data were collected.

Also, we need that, from the supervision center, the communication were via PSTN or GSM modem, using the MODBUS protocol.

We don’t need any output, because we only need to collect data, store them and transmit them when the user requires it from the supervision center.

We’ve seen 2 models of PLCs: Cubloc and Millenium II, by Crouzet, but I’m not really sure it the fullfil our requirements. Can anybody recommend us any easy-programming PLC? We’re high-level languages programmer and we’re very green in this type of devices.

Any help would be highly appreciated!!

Thanks a lot!!

Jose Sega

 

My experience is mostly with Mitsubishi Electric (also called MELSEC) PLC's.

When it comes to MELSEC, there is no problem with realtime clock, timestamps and protocols as Modbus, e.g. Modbus TCP.

Check the Q Series family with your local salesman or check e.g. http://www.beijer.se

You're welcome,
Mike

 

Jose,
In this day and age almost any PLC can keep track of a date/time stamp.

We usually specify Allen Bradley or Direct Logix (Automation Direct), but that is customer driven by our market.

What common in your target market? Use that platform if you can. Don't try to make your customer adapt to you; you should adapt to your customer.

Michael R. Batchelor
www.ind-info.com

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Look at this one.
http://www.unitronics.com/
Is easy to program , low cost , the software tools are free , including the communication driver.

 

A lot of options:

1. Siemens S7-200
2. AB Micrologix

Both are excellent, and are small sized and expandable. Easy to program also.

Best Regards,
Shahid

 

I agree. The difference in capabilities and costs among PLCs these days is so small it is not worth arguing over. They all have minor pluses and minuses compared to their competing products. But they will all generally do the job.

Your customer's preference ought to be the deciding factor, eveything else being equal.

 

What you are describing is an electronic recorder. By definition, recorders date-stamp data and are designed for analog inputs.

It can be done on a PLC, but an electronic recorder is designed to do that exactly, without a lot of setup.

Look at something like Honeywell's Trendview:
http://hpsweb.honeywell.com/Cultures/en-US/Products/Instrumentation/paperless/default.htm

If your customer wants a PLC, give him a PLC, but if you need 10 analogs saved on flash and available via Modbus, get a recorder.

David

 

Like the other guys have said, everybody has pro's and cons but all will essentially do the job. Take a look at the Schneider Electric Twido product family.

http://www.telemecanique.com/en/products/index_fon5_fam11_aut_modicontwido.htm

Depending on the model selected you can have a built-in RTC or an add-on RTC module. Free programming software and 2,4, or 8 channel analog I/O modules all for a very compact size. Also Modbus communication is standard.

Hope that helps.

 

I noticed a few answers to be biased (marketing). I don't like them personally as I am a Siemens S7 man, but the GE Fanuc is used a lot in the industry you are referring to. They are cost effective, and have a lot of Comms options for PSTN, etc. And King Fisher RTUs are also used a lot in that industry, and has a lot of comms options, and data storage/manipulation options.

http://www.rtunet.com/products/kingfisher-series-ii/

hope this helps.

 

Hi
I suggest to use Twido PLC, because it is very easy and you can download TwidoSoft from Schneider Electric homepage. If you can see lot of solution with you Twido http://www.konys.hu. Anyway if you can help or program example I can send to you (my e-mail: [email protected])

 

Take a look at http://www.beckhoff.com. You can find PLCs at different prices, programmable in standard IEC61131 languages. I have got experience with Siemens and Allen-Bradley and in my opineon Beckhoff is the only PLC that allows also high level programming style language.