In general a "fieldbus" is not suitable for realtime coordination of Servo drives. Profibus is a good example. Profibus can run at 12 megabaud and Siemens uses it to link their PLCs and Servo drives sometimes but to do so you have to lock down the Profibus link via some special modes which makes the I/O update very predictable. That special mode is only available with certain master and slave devices.
Modbus has a long history and is very popular for connecting field devices. Modbus TCP (which I believe is supported by Classic Ladder) should be fast but it is not really suitable for use in a servo motor update loop for coordinated control. It was never designed for that. CAN is pretty slow compared to Profibus. I'm not familiar with EtherCat. Sercos was specifically designed for Servo drive coordination and a number of companies use it for that. http://www.sercos.com/ But Modbus and Modbus TCP are plenty fast for general purpose I/O and it is great for tying a hardware PLC into EMC2. It all depends on what you want to do. Dave christian bazungula wrote: > Hello Micheal, > > Thanks for advises, i'll take into a count. > > On Tue, Oct 27, 2009 at 2:44 PM, Michael Haberler <mai...@mah.priv.at>wrote: > > >> Am 27.10.2009 um 14:21 schrieb christian bazungula: >> >> >>> Hello Dave, >>> >>> Thanks too much for your answer. I'll check out Modbus and after >>> i'll let >>> you know. >>> >>> To answer to your question, i'm trying to see if there is a way to use >>> fieldbuses in communication between EMC2 and machine. This is to >>> reduice the >>> wiring between them. >>> >> This will also increase latency and introduce queuing delays. So >> there's a limited range of options what you can actually drive over >> such a bus, in particular a slow one like Modbus - sureley nothing >> with hard realtime requirements. >> >> so far Modbus drivers have been used to control spindle VFD's, and >> even here some operations have a feedback loop (like "spindle at >> speed"). >> >> Maybe SPI is an option. Either way, count wires before and after the >> bus exercise.. >> >> >> -Michael >> >> >> >>> Thanks >>> >>> Christian >>> >>> >>> >>> >>> >>> >>> On Tue, Oct 27, 2009 at 3:09 PM, Dave <e...@dc9.tzo.com> wrote: >>> >>> >>>> Check out Modbus. It is already implemented in EMC2 via Classic >>>> ladder >>>> and it works. >>>> >>>> What are you trying to do? >>>> >>>> Dave >>>> >>>> christian bazungula wrote: >>>> >>>>> Hello everyone, >>>>> >>>>> I would to know how can i use EMC2 or which module (code,...) may >>>>> i use >>>>> >>>> in >>>> >>>>> order to send informations generated by EMC2 to a fielbus ? >>>>> >>>>> Secondly, which kind of fielbus (CAN, Powerlink,...) will be >>>>> usefull to >>>>> >>>> that >>>> >>>>> task ? >>>>> >>>>> Thank you for help >>>>> >>>>> Best regards >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >> ------------------------------------------------------------------------------ >> >>>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >>>> is the only developer event you need to attend this year. Jumpstart >>>> your >>>> developing skills, take BlackBerry mobile applications to market >>>> and stay >>>> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >>>> http://p.sf.net/sfu/devconference >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> >>>> >>> >>> -- >>> Bazungula Christian >>> >>> >> ------------------------------------------------------------------------------ >> >>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >>> is the only developer event you need to attend this year. Jumpstart >>> your >>> developing skills, take BlackBerry mobile applications to market and >>> stay >>> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >>> http://p.sf.net/sfu/devconference >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > > > ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
