Siemens - Wago modbus comms


I am struggling with modbus tcp between a wago 750-842 and a siemens 1214c.
My understanding is that the 750-842 defaults to a modbus server with no application program loaded.
The 1214C has MB_client configured to read the 750-842 holding registers.
But it doesn't read anything , no errors but a status 7002 ( waiting for server response )
I am using Codesys v2.3 and TIA v12 to program the devices.
Attached are pics of the 750-842 and 1214C configuration.
What am I doing wrong?