Igor Chudov wrote: > I think that the trend in industrial machines, is to use Ethernet as > much as possible inside industrial machines. On the surface, it > appears to be a very attractive option, with all devices hooked up to > the network switch and communicating seamlessly, without the mess of > wires. What are the implications of this for EMC? > In must cases, Ethernet is not a low-latency communications scheme. If you use a switch, as opposed to a hub, then there is an added delay as the complete packet needs to be read in by the switch before it can be sent out the appropriate port.
If this is loose real-time, like for coordinating various systems in a machining cell, robot arms, parts handlers, pallet changers, etc. then a few milliseconds delay here and there are insignificant. If it is for the primary motion control, then I think the latencies are too high. I looked at a stripped-down ethernet for communication with my PPMC boards, and the general consensus among some people who worked with RT ethernet was that the idea of > send request, get response, send update < all in one millisecond, was just not possible. Jon ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
