Low cost PLC with TCP/IP and GPS

[mk2000]

I am looking for a PLC/system with the following minimum requirements:

1. Low cost! ($750 USD)
2. 6x 4-20 mA input (if three can be thermocouple input would be good)
3. Wireless connectivity via TCP/IP, GPS and 3G (ability to choose which one)
4. Ability to log approx 1800 data points
5. Compatible with 240V 50Hz power
6. Casing not required (can be exposed I can organise that)
Can you please recommend a product which complies with the above.

Thank you in advance.

 

[Skogsgurra]

I think that such a unit can be custom made at a considerably lower price. It depends a lot. Shall it be configurable and expandable? Shall it run a certain class of applications - or every type of application from washing machine to paper machine? What type of input/output in addition to 4-20 and thermocouples? 24 V DC, 230 V AC, analog, triac?

And lastly, what volumes are you thinking about?

The S7, supported with Westermo modules, can - of course - do it all. Not sure about the costs, thogh.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[jimgineer]

I wasn't aware that GPS was a 'feature' that came with any PLC. Thinking out loud, I'm wondering how the designs of the Garmins, TomToms, etc, pull off a system that they can make and sell for 100 dollars.

I'm not sure on your request for 50Hz 240VAC. I was under impression that PLCs generally take 24VDC, 12VDC, etc. I mean, what are you trying to do, and why can't you rectify your AC source to DC, or even, use a battery?

Can you give more information on your application?

 

[mk2000]

Just an expansion on my requirements:

Device type: I guess it can be called a RTU technically speaking?

Input signals: I have not selected the instruments yet, however 4-20mA seam to be the most common type. However I am flexible.

Output signals: None required.

Power supply requirements: I just though I put that in so to make sure it is covered. The mains supply here is 240VAC 50Hz.

GSM, 3G Wireless connectivity: As long as it has the ability to connect to a modem allowing wireless connection I am happy.

I hope this helps.

Thank you.

 

[itsmoked]

So you mean GSM NOT GPS?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mk2000]

Yes apologies for the typo.

 

[rjmaster19]

I hate to sound like a pessimist but I seriously doubt that you're going to find a PLC with those options at that price.

Additionally I am not aware of any PLC that natively supports GSM or 3G data services.

That being said your best bet may be a combination of an Automation Direct (automationdirect.com) PLC with a cellular modem. I've used the Raven X, but there are cheaper versions out there. An automation direct with the I/O you specified should run you in the general area of 1000 dollars. A cellular modem in the range of 200-500.

(On a side note you could use an additional router at your PLC and use a wireless bridge to get where you need to go. I just did this at my house)

 

[ykee]

No outputs -- Are you looking for a PLC or a data logger?

 

[ykee]

Maybe you are looking for something like this:

http://www.omniinstruments.co.uk/products/product/moredetails/r-log.id410.html

 

[slavag]

Hi.
Something like to this

http://www.moxa.com/product/ioLogik_E2262.htm

with additional

http://www.moxa.com/product/OnCell_G3100.htm

Best Regards
Slava.

 

[dV8r]

While we are "wish'n", I would like a PLC for under $10,000 that came with a HUMMER to get me back and forth between it and my house.

 

[OldPfart]

Omron CJ1 PLCs with a serial card and external modem can do the job but not at that price. I do online programming via GSM/3G modems all the time and use the PLCs to send text messages to recipients via the same modem.
The PLC has some nice functions such as calculate number of bytes for message sending etc.
If you are in Ozz a processor with Ethernet built in would probably cost you $2500, analogue card $1000, serial card $800 etc.
I always use 4-20ma by the way - never voltage inputs. 4-20ma is far less prone to induction and there are no voltage drop problems.

 

[AndyHill]

Is there not a small Mitisibusi PLC that accepts a GSM Sim card.

 

[jraef]

Siemens S7-200 micro PLC has a GPRS/GSM modem option. They are used all over the world for RTU applications like that, Siemens calls the system Sinaut. And I know they are not the only ones, they are just the only one I know of for sure.

http://www.automation.siemens.com/net/html_76/produkte/060_produkte.htm

And for those o you who think I am proselytizing, I no longer work for Siemens. I just happened to know this.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[Anton1988]

Have you considered a crouzet plc the software is £10 and the hardware is cheap with modules that you can add on. I got some with 16 Inputs 6 of which are 0-10v. lcd display and 10 relay outputs the plc is an xd24 i think and cost about £120 gbp. They also do a gsm modem when i last looked that was about £250 and they do an ethernet module at about £100.
So far that's £500 gbp. They also do converters to change 4-20mA and /or thermocouple to 0-10v so your sensors can be used unfortunately i haven't got prices on these as i haven't used them.
Units are powered from 12v,24v ac/dc 110vac or 230/240vac so no PSU required.
The units are very easy to program and offer fbd, ladder and sfc programing methods.

Crouzet also offer a custom build service but i don't know if they have a minimum order level for this.

Hope this helps