ACE 3640 ethernet connection to Compact Logix

I am trying to set-up some communication between the ace and a Compact Logix L23E plc using Ethernet connection. This plc has been set up to map the data block as PLC 3,5/ SLC Mapping.

I am looking for any assistance I can get specifically on ( within the ACE):

1. The Eth1. Port setting
2. The PLC Table [231] settings

The error message I get is:
#910 PLC switcher module, cannot find the key in switcher port table.

Any help/guidelines will be appreciated.