Small PLC with +/- 0-10V AO

Hi,

Today all PLC suppliers have their own small "simple" PLCs(Siemens LOGO, Mitsu Alpha, Crouzet.....) with some few I/Os, limited expansion possibilities and a small display.

I work a lot wit hydraulics and most proportional valves need a +/- 0-10V signal. I have looked at some of these small PLCs but they only have 0-10V not +/-0-10V. Does anyone know a PLC with this type of I/Os.

by 'small plc' do you mean programmable relays like Moeller Easysoft & the Allen Bradley Picos? If so, check out the Pico on the AB site...look for the GFX

Yes, that size. The Pico however has no such AO. I'll take a look at Moeller.

Unitronics M91. 2-line text display, normal ladder programming, free software, and there is a model with analog I/O.

www.unitronics.com

Tim he wants -10v to = 10v is there one that will do that?

Horner, www.heapg.com, makes a unit called OCS which is a plc and hmi in one, they also have a mini version. The analog is capable of +/- 10vdc : http://www.heapg.com/OcsManuals/MiniOCS-RCS-OCX-RCX/MINI%20I-O%20Data%20Sheets/Complete%20Mini%20I-O%20m058101.pdf

Note: Horner has been a GE third party vendor for many years. The software for programming their units is called CScape, its free and downloadable from their site. It is very similar to the GE style of programming...minus the % issues.
http://www.heapg.com/company/OCS/Horner%20Electric%27s%20Mini%20Operator%20Control%20Stations.htm

Whoops!

Well Ron, ya got me there. I retract the suggestion - overlooked that part.

Come to think of it, I've complained to them before that they should offer +/- analog controls...and a high-speed counter of at least 20Khz. For such a strong offerring, those little tidbits can make all the difference.

TM

You really won't see a +/- 10 VDC signal in a micro PLC. You will typically find this range in modular systems.

We have a customer that required +/- 10 VDC but were only able to do +/- 5 VDC. They were able to change the scale of their device to accomdate the smaller range. If you were unable to modify the range, then you might want to consider an amplifer.

Our Smart-PAK PLUS - a micro PLC, can be configured for +/- 10 VDC analog inputs and +/- 5 VDC outputs.

In looking at other manufacturer's products, AD offers +/- 10 VDC in the 205 series but not the 05/06 series.

Aromat does offer an expansion module in it's FPO series that can do the +/- 10 VDC range.

AB's micro logix 1000 offers one analog output but it isn't +/-

This is just a couple that I have looked into. If you go to the links page provided on this site, you can do your own research - http://www.plcs.net/chapters/links.htm

The likelyhood that you will find the +/- 10 VDC output that you are looking for in a smart relay, is very very remote. The design requires two voltage rails...and given the price of this type of product, I can't see that happening.

Hope this helps you.

God Bless,

The easiset solution is probably going to be a signal conditioner to convert the 4-20 mA or 0-10 VDC output from the PLC to your ±10 VDC. M-Systems, Action Instruments, A-Pi, and many others offer this.

Where is Jay Anthony these days?

The OMRON CPM1A offers +/- 10vdc analog output
http://oeiwcsnts1.omron.com/pdfcatal.nsf/PDFLookupByUniqueID/9F255B35944B008086256A29005C88D7/$File/D11CPM1A0301.pdf?OpenElement

The CPM2A:
http://oeiwcsnts1.omron.com/pdfcatal.nsf/0/D013F8B83069774C86256E63005E3A1C/$file/D11CPM2A0304.pdf

I dont know of a nano/smart relay that offers alot in analog. Another option may be to use proportional valves with serial or fieldbus communication, never hurts to look at different options.

Thank you all for your answers.

The idea of using a "small" PLC was that when we make Hydraulic systems normally they are a part of a large machine with it's own PLC that takes controll of the Hydraulic units with all of it's valves.

However sometimes we make special machine solutions where our Hydraulic kit is the main unit. Then there is normally few I/Os involved and we need a small display for settings and +/- 10V outputs for proportional valves.

Proportional valves with fieldbus connections are still fairly expensive but maybe someday....