There will have to be some downtime but, as with the nature of most projects, it is to be planned, scheduled, and fixed in timeframe so as much as possible will have to be done before shutting down. That is one reason I need to get an understanding of how the I/O will map over Ethernet, so the program can be added/changed as much as possible up front. I understand the old, one scan vs. new, continuous scan concept but, if I understand, this will be predicated on converting completely over to Logix hardware. Using the old wiring arms will be convenient but not that big a deal in the big picture. It is a full rack but all 16-point so not too bad to wire to new cards if necessary. However, if everything has to be replaced as explained, it will not be much more for the wiring adapters!