Control.com - Nerds in Control

Hello Everyone,

I was wondering if any of you could give me some insight into how to communicate with Ethernet IP devices from Java.

I already have written my own Modbus TCP/IP driver in Java simply using the spec. However, I now realize that the specs for Ethernet IP are pretty locked down by ODVA. I also noticed some outrageous requirements for using it including hefty costs.

I am wondering at this point what options I have. Personally, I would like a Java based solution due to the posibiltiy of porting it to multiple operating systems. I know Microsoft is king in the Controls world, especially with Allen Bradley, but I'd prefer to be able to use Linux.

My reasons for this are simply that Windows 2008 Server is quite expensive and Vista is not fit for a production enviroment in my opinion.

So what options do I have here? Is there a direct driver available? Would I be forced to use an OPC server? Could you please provide some suggestions?

Thanks,

Jon

You can, in fact, do it yourself. You can even get away without paying a bloody fortune, assuming you're not trying to sell a product with "EtherNet/IP!" stamped on it.

Having said that, if you've implemented Modbus/TCP in Java you have NO IDEA what's in store for you to implement EtherNet/IP. We spent over six months getting it to mostly work with a handful of devices. (Granted, we did it in C. Java would be easier, but not THAT much easier.) On a difficulty scale of 1 to 10 I would put Modbus/TCP at 2 and EtherNet/IP at 9.

I'm not aware of a commercial or open source EtherNet/IP implementation in Java. That doesn't mean they aren't out there.

Hardware solutions are possible. AnyBus makes a Modbus/TCP to EtherNet/IP device. Hilscher makes a PCI card that handles EtherNet/IP in hardware and has Linux drivers. You'd need a bit of JNI for that one, but not much. Woodhead has something similar.

By the way, if you only want to send messages to a PLC, as opposed to control a device like an I/O block or drive, that's a much simpler subset of the EtherNet/IP spec. Still way harder than Modbus/TCP.

-James Ingraham
Sage Automation, Inc.

I may look into Any Bus. We currently use gateways to talk to our SPI devices over Modbus TCP, so another gateway could make sense.

Are there any other providers I should try?

Thanks,

Jon

I've written a Java driver and it runs on Linux. But I can't give it to you because it's not ODVA licensed and possibly illegal.

Either you pay ODVA and develop your own driver or you pay me so I can pay the license. You can then get the driver for free.

Either way, you are stuck with hefty costs.

Hi there,

I agree with James on the difficulty scale, EtherNet/IP is quite complexed. You could use a gateway Modbus TCP slave to EtherNet /IP master. HMS has such a gateway, for more information please go to:
http://www.anybus.com/support/support.asp?PID=371&ProdType=Any bus%20X-gateway

You will need RSNetworx for configuration of the EtherNet/IP network.

If you have any questions regarding this solution, please let me know.

support@hms.se

/Patrick L

Yes, like most Automation Vendor perversions
of the term "Open" it seems the Open part refers
only to your wallet. And you stand to get sued
if you actually try in any way to Open anything
else about it. It's the Big Lie form of propaganda.

But it works, people here call some of the worst
examples "Open".

Regards

cww

You might want to look at tuxEIP:

http://www.tuxplc.net/index.php?page=tuxeip

It's C, but could be ported to Java. I have thought about trying this myself. If there's enough interest, perhaps the tuxEIP author would be interested in doing a port.

Within http://pvbrowser.org we also use
http://www.tuxplc.net/index.php?page=tuxeip

But pvbrowser is C/C++. If you want to make use of tuxeip from Java you might generate a language binding using http://www.swig.org/