PV550 and Control Logix

Hi! I'm having problems getting the comms set up right! I have a PV550 2711-K5A20 and a ControlLogix5561 talking through a 1756-ENBT card. the error message on the HMI reads;

634 Read Error

IP: 192.1.1.2, Path:1 0 SRV: 1 CLS:0 INST: , ERR: 5

My comms card has the IP: 192.1.1.2 and sits in slot 1 of the rack.
The Plc is in slot 0
The panelview has the IP: 192.1.1.5 and is connected through a hub/switch to the system.

Anybody got any suggestions??

634 Read Fail

a> Comm Status - ControlLogix Tag or address does not exist or is the wrong data type - Check tag address / Check for data type mismatch.

b> Designated slot does not contain a ControlLogix Processor - Verify ControlLogix slot location

Suggest a> is your most likely problem - incorrect Tag address or data-type