Raid Admin can’t connect to raid

I have a xserve G5 and a xraid, and have the following problem. I have inserted a new disk in the raid, and open the Raid Admin in order to activate the harddisk. But I can't connect to the raid. If I try to say Add system, it doesn't show up, and I have also tried to connect to the raid using the IP address (which I got from scanning the network for the MAC address), but it still can't find the raid. I have also tried to ping the raid but it doesn't respond. As the server and raid are connected with fibercables, I can see that it otherwise is running fine - the exsisting drives on the raid works fine on the server. Any suggestions on how to connect to the raid? (hopefully without needing to restart too much). TIA, Peter