Concerning remote I/O over Ethernet : Beckhoff has also come up with a new Ethernet based fieldbus system called EtherCAT (www.ethercat.org), it is much faster than the Modbus TCP (60 ms cycle time, I read once, too slow for most control applications). You can not have a control loop running over Modbus TCP, with EtherCAT this is possible.
EtherCAT is basically not more than embedding "EtherCAT telegrams" in standard Ethernet packets (at least from the master viewpoint). I think it is possible to write some code that supports the EtherCAT protocol stack and run this with the real time Ethernet drivers of rtnet. Actually you could do the same for the "Ethernet Powerlink" protocol(B&R company). Both protocols are supported by a lot of manufacturers. This is probably much more realistic way to have remote I/O over Ethernet using rtnet stuff, than asking manufacturers to support the rtnet protocols. Cedric. -----Oorspronkelijk bericht----- Van: Jan Kiszka [mailto:[EMAIL PROTECTED] Verzonden: maandag 13 december 2004 23:55 Aan: Alexander Fedtke CC: 'Matteo'; rtnet-users Onderwerp: Re: AW: [RTnet-users] Remote i/o Alexander Fedtke wrote: > Company Beckhoff (www.beckhoff.de) offers an Ethernet Bus coupler that can > be expanded with a lot of digital/analog IO modules > http://www.beckhoff.de/english/busterm/bk9000.htm > IMHO price is 236EUR + TAX + prices of IO-Modules > > Wago (www.wago.com) offers a similar modular distributed IO system. > > Advantech offers the ADAM6000 series of complete > Ethernet-to-Digital-IO-Modules (approx. 180EUR + TAX) and > Ethernet-to-Analog-IO-Modules > http://www.advantech.com/products/sub_category.asp?Category_ID=1-LXK3G&P D=AD > AM > > IMHO both of them are working with Modbus over IP (don't know TCP/UDP) > Seems to be hard to modify their firmware... > > Jan, maybe your institut can make a deal with Beckhoff/Wago/Advantech to > make their equipment rtnet-ready? > I would join that interesting 'subproject'! > :o) [big smiley!] I could tell you some stories about talking to company representatives and asking for Linux and/or RTnet support for their products. And those who make a living of such porting work (Linux service providers) could actually tell you even more... Basically, the companies are all very interested if such add-ons come for free ("Isn't it Open Source? Then why does it cost money to make it work?") and if they don't have to reveal too much internal information/code. They are all cooking with water, and they don't like others to watch that it is not always really cooking. ;) Currently, it is still a bit too early to persuade larger vendors that RTnet support could be interesting for their customers and may help them to sell even more devices. Things may get easier if the company is smaller and sees such add-ons as distinguishing features for their products - that's why it may be worth contacting the Barix guys. But time will come for RTnet, I'm sure. I just heard of a new interesting commercial request about RTnet today - if this comes to real, it will be another significant push for the project. We are always open for cooperations with automation equipment vendors, but it has to be giving AND taking. And when there will be a chance to hack RTnet in some IO module, I will surely let you know! Jan *************************************************************************************** This e-mail and any files transmitted with it are confidential. They may contain information which is protected by intellectual property rights and are intended for the sole use of the individual or entity to whom they are addressed. This communication represents the originators personal views and opinions, which do not necessarily reflect those of the company or its subsidiaries or associated companies. If you are not the original recipient or the person responsible for delivering the e-mail to the intended recipient, be advised that you have received this e-mail in error and that any use, dissemination, forwarding, printing or copying of this e-mail or attachments is prohibited. If you received this e-mail in error, please immediately notify [EMAIL PROTECTED] and delete the information from any computer. The contents of an attachment to this e-mail may contain software viruses, which could damage your computer system. While the sender has taken every reasonable precaution to minimise this risk, the sender cannot accept liability for any damage which you sustain as a result of software viruses. *************************************************************************************** ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ RTnet-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/rtnet-users
