You do not set the IP Address for the CRA. Unity Pro will automatically set the IP Address for the CRA when a remote drop is added to the configuration. It will follow the IP Address A scheme that is set up in the processor IP Config. You will notice an Ethernet Network table on the screen that will house the CRA Device Name and corresponding IP Addresses. If you feel the need to change the IP Address of the CRA's, you can edit them from that table.