With ControlNet and Profibus (and other protocols) it is possible for several controllers
to share IO racks and (IO-)buses. Does anyone know the limitations:

1. Is it possible to share on card or channel level, or is it only possible to share the bus itself?

2. Is there any differences between Allen-Bradley's and Honeywell's way of using ControlNet?

3. What is the disadvantages with sharing IO?

Regards,

Roy Seland
Instrument Engineer
Umoe Oil and Gas

 

Sorry that I can't answer your specific questions about ControlNet but if you are trying to share data between several controllers you may consider a technology based on shared memory. It is much faster, has higher throughput, deterministic, and made to share data between PCs / servers, etc. There is a couple of suppliers. Try looking at Systran.com and the product called SCRAMNet.

WjO