4. WHICH RA PRODUCTS SUPPORT EIP from RA website....?

Refer to Section 2 above, "Overview". All devices which communicate with the ControlLogix controller (via 1756-ENET or 1756-ENB) over Ethernet must use "EtherNet/IP". All future standard RA Ethernet products should support EtherNet/IP. The PLC5 and SLC5/05 have had this capability for some time, as well as the RSLinx and Interchange communication products from RSI. The PLC5E added EIP support in early 1999. There are several hardware platforms being supported (Ser. C, D, and E) with firmware upgrades for each. Although not currently the latest revision, the first PLC5E revisions to support IP were:

Series C, Revision N.1

Series D, Revision E.1

Series E, Revision D.1

The MicroLogix controllers support EtherNet/IP via the 1761-NET-ENI (Ref#11). The ENI does not utilize the same services as the SLC-5/05 does. At this time we do not have information available that discusses how to access the MicroLogix via the NET-ENI, other than what is described in the manual, Ref#11. The PLC5 "sidecar" module first supported EIP at Series B, Revision A. The SLC5/05 was updated with EIP support in May 1999, with Series A firmware revision OS501, FRN5. If the SLC5/05 is an earlier revision, it can be Flash updated with new firmware. . All Series B and C SLC5/05's support EIP. At this time, other RA EIP products include the new PowerMonitor and PanelView products, and IO

Adapters (1756-ENET, 1756-ENB, 1794-AEN, 1734-AEN, 1769-AEN)

See the document - http://www.rockwellautomation.com/enabled/pdf/eipexp1_2.pdf

So, your PLC5 with the sidecar may indeed be viable.