> I know IETF thinks IP is the center of the universe and the > one true religion. But not in process control it is not. A > PIC controller comes with 384 bytes (BYTES, not kilo) of RAM. This is wildly out of date. For at least the last 10 years cheap and common PICs have been made with more RAM than that. The IP stack has been implemented in 1K bytes of code that will run on the 8-bit PIC CPUs. > Good luck getting an IP stack in there. And even if you use a > bigger processor with a built in TCP/IP stack you can only > run it over Ethernet type media. You can't use RS485 which > looks a much better bet for hardwired home automation systems > to me, it is what process control has used for decades. Exactly. Process control doesn't need IP at all at the edge of their network. They have other solutions that work well for them. Whether it is I2C or one-wire or RS-485, data can be relayed onto an IP network by devices which speak both protocols. There is no problem here. --Michael Dillon _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf