DeviceNet Vs. Ethernet

Hi All,
I am having some difficulty understanding a customers's network architecture.
They have a PLC1 that communicates via Devicenet to MCC(Motor Control Center,they pick up pump status for etc) and then the PLC1 communicates via Ethernet to PLC2 and PLC3.(PLC2 and PLC3 need the MCC pump info to operate)
Why would that be,why can't it be devicenet from PLC1 to PLC2 and PLC3,or why can't it be Ethernet all the way round meaning PLC1 Communicates Ethernet to MCC and then communicates Ethernet to PLC1 and PLC2.
It would be of great help if someone could give a link or reference to Devicenet Basics and Ethernet Basics.
Thanks

Maybe this will help

http://www.circuitcellar.com/library/print/0998/Brady98/brady-98.pdf

http://www.bb-elec.com/ethernetbasics/Ethernet_Basics.pdf

iahiii_2005 said:

Hi All,
I am having some difficulty understanding a customers's network architecture.
They have a PLC1 that communicates via Devicenet to MCC(Motor Control Center,they pick up pump status for etc) and then the PLC1 communicates via Ethernet to PLC2 and PLC3.(PLC2 and PLC3 need the MCC pump info to operate)
Why would that be,why can't it be devicenet from PLC1 to PLC2 and PLC3,or why can't it be Ethernet all the way round meaning PLC1 Communicates Ethernet to MCC and then communicates Ethernet to PLC1 and PLC2.
It would be of great help if someone could give a link or reference to Devicenet Basics and Ethernet Basics.
Thanks

Click to expand...

Well, I'm thinking that a Devicenet scanner for the two other PLCs would be more expensive than an ethernet scanner.

Also, Devicenet, as its name imply, is really focused around devices, and the MCC is filled with devices (COntactors, drives etc.). If the other 2 PLCs only need status information and are not really controlling the MCC, then going Devicenet would be expensive.

As to why not go ethernet all the way, I can guess that they want to keep the diagnostic info available in Devicenet between the MCC and PLC1.

Just guesses