Wireless or Ethernet??

hi guys,

Are there any devices on the market that will take a 4-20mA signal IN, and communicate across Ethernet, to a reciever, and ouput the 4-20mA signal?? The reason I'm asking this is that I have a lone flow transmitter, which we are looking to tie into the PLC, but it sits in a building seperate from the PLC. We might be able to get some hard wiring out there, but it looks as of right now the old conduit has been filled in. Wireless is an option, but because of the nature/location of the 2 building, it may not work right.I have looked at wireless trnasmitter/reciever units from OMNEX and SCADALINK. Now, the reason I aked about the ethernet, is because we do have a netowk drop out there. Has anyone one ever seen/done anything like this before?? OR do you think the Wireless might work?? If you want more imfo on the situation/location of the buildings, as well as the building materials, let me know.

Thanks,

Andrew Evenson

Andrew

Your question stirred something sitting in the back of brain regarding something we tried about 3 years ago.

We had an anonometer (wind speed meter, I can't say it let alone spell it!) in a remote part of our site. The output from this was 4-20mA. We needed to read this wind speed in our control room about 1/2k away as the crow flies. What I believe we did was feed this signal into a remote analogue unit, then send this signal via ethernet to another output unit in our control room. I think that the remote I/O units were made by a company called Wago.

Unfortunatly, my memory of this is a bit sketchy, and this unit has been removed and binned.

Try the Wago web site, http://wago.com

Maybe they can help you with your enquiry.

I am not sure if the results of this experiment were satisfactory, but it might be worth you investigating.

Paul

Opto 22 has wireless ethernet I/O. You may need another processor in the middle, though. Also try Locus (ww.locusinc.com)

Opto 22 also has Ethernet I/O called SNAP ETHERNET I/O
http://www.opto22.com/products/snapenet.asp

B&B Electronics sells an Analog Ethernet with DO that I am not sure will work for you or not.
http://www.bb-elec.com/product.asp?sku=ADAM-6017&dept_id=99

I am not sure what PLC you have but there is always the option of an I/O system ..if AB then maybe Flex I/O
http://www.ab.com/catalogs/b113/io/1794.html

Ethernet

Andrew Evenson

Hi, I can only help you if you have a A-B PLC at each end.

Input your analog (4-20) into a IFE, write a message send it over the
ethernet communications to the second PLC and output the signal VIA an OFE module. You should be able to do this wireless, fiber optic, blue hose, phone modem.

After thinking of your situation I'm almost sure this is too simple for your situation.

By the way Ethernet is the oldest form of computer-computer communications and is very reliable.

Good luck
Roger

Check out this link.

http://www.omnexcontrols.com/wireless/hs900/hs900.html