Ethernet i/o or plc network?

[larry818 0]

Hi All, I would think what with all the media hype about ethernet networked PLCs, I would find what I want more easily. What I've got is two applications where the plc is separated from it's i/o by about 2000' and it's impractiable to run cable. So I want to connect them wirelessly by ethernet. But from several days of searching, I only find answers that run into the many thousands of bucks. In fact, for these applications, I don't really even need a plc, just wireless monitoring of contact closures. I've been a long time mitsubishi user and they're just come out with an ethernet module, but it's useless for this application. You can only use it to program and monitor plcs, but even tho the plcs are on a network, you can't network the plcs. Stupid. So far the cheapest answer I've come up with is plc > rs485 adapter > lantronix serial to enet > wireless bridge > back again. It's still running lots of $. I know Omron makes it's own wireless connection, but at $1,200 each, I'd prefer to go with off the shelf 802.11b stuff. Does anyone know of a decent answer to this requirement? Ideally I'd prefer a PLC that knows of ethernet natively and can talk to i/o or other plcs over the ethernet. Thanks, Larry

[panic mode 246]

how many inputs we are talking about? how are they distributed?

[KinK 0]

Hi Larry818 I have to say that no solution that you look at that will be robust and reliable will run you less than $2k I have looked into this quite extensively and that is about the best price you will get. the only thing that you may get to be cheaper is if you set up a local computer and then use your reg home type wireless to remote into it or use it as a conduit. this type of system using older pc's was the only one that came in under 2k. peace

[larry818 0]

There's only like 3 inputs and 2 outputs at each of three places. Thanks, Larry

[larry818 0]

It seems funny to me that with all the hype about ethernet and plcs about now that there's no actual economical solutions... I have found a place that sells a replacement os for the linksys wireless routers. I was thinking about using that with the meau fx2n w/ enet adapter and hacking the linksys to read data from and write to the plcs. There's some .dlls I can buy currently that I can set up a program to do this if I want to dedicate a 'puter to the project.

[Pierre 1]

Have a look at Phoenix or OMNEX they have good product for such needs.

[larry818 0]

Hi and thanks, I did look at them, but they're pretty expensive also. I may end up using their 4-20ma wireless transducer for another project, tho... What I finally got was an Automation Direct 05 plc with ethernet plugin. It was about $500 usd for two plcs and two ethernet cards. I've really gotta test them out, tho, as they are the crappiest things I've ever had my hands on.

[Guest avoTek]

Is there a wired ethernet network available? Or are you going to try to add a wireless gateway in between the two controllers? Either way, you should check out the BarioNet ethernet i/o controllers at www.datanab.com. They are way better than the Automation Direct stuff. You could probably get them for about the same price and you don't need to buy any software to program them with. They'll talk peer to peer as well as modbus/tcp or modbus/rtu to any generic i/o product that runs on those networks. I would buy a couple of BarioNets & a stick a wireless gateway in between them and that would take care of it.

[larry818 0]

Too bad I didn't see the BarrioNet before I bought the AD stuff. It's a little more expensive, but seems much more useful. I may buy them anyway. Thanks, Larry

[Sleepy Wombat 27]

Hey there Larry, ever thought of just using Digital IO Radio Links, I have personnaly used the EPLRPO gear as listed below and found them to be quite reliable, epsecially since you are only trasmitting a few IO's. Elpro Link The series i believe that you would be looking at would be the 905U

[mgvol 0]

DATA-LINC also make an RTU unit w/discrete I/O, analog I/O, and a built in wireless modem. A pretty neat little package.

[santiago 0]

I use Cellular phones with modem for remote connections , cheap and quite good , with its limitations but it works