I think that you have got it right.
Inverter terminal, FC,is a 12V output. No connection to PLC
Inverter terminal, FR, is the 0..10V input. Connect to D/A #1 output on pin 14 on the DB15 connector.
Inverter terminal, FC, is the analog ground input. Connect to the Analog ground on pin 9 of the DB15 connecter.
You should use a shielded cable with a pair of wires that are twisted together. Think cable used for microphones. The cable shield must be connected ONLY to the ground terminal on the inverter.
The precautions on the cabling between the PLC and the inverter is because the VSD and electric motor can create an amazing amount of EMI and RFI that can raze havoc with analog signals.
A VSD drive/inverter combination can be the basis of a very powerful, and unexpected radio transmitter. Follow all of the inverter mfg's specs on wiring, shielding, grounding and the use of RFI filtering to avoid knocking planes out of the air.
Gary D.