Some lessons we've learnt:
You may find that the RS485 is not well connected: this can be because the clamp catches on the plastic. So don't put the wires in too far when you push it in and tighten the screw.
The meter and collector ids need to be programmed into the Concentrator in order to read it.
Don't set up the concentrator as G3-PLC, but rather as Relay G3-PLC.