Ah! The glass is half full or half empty problem!
So the device can't tell you the IP address it has so how can you find out?
The easiest way is to use a network sniffer plugged into a local hub so you can see the printer coming on line. Here's a listing of some free network analyzer tools: Five free network analyzers worth any IT admin's time any one of them will be fine. Just make sure you have permission to use them on your network!
You want also have a dumb hub as most switches will block the port from seeing the others data stream (make sure printer & analyzer on plugged into the same hub). If you have access (or your network has them) to a smart switch with a RMON probe they you can leverage the RMON probes data collection.
The last way while a bit harder might work. As it turns out many printers allow you to define the printers name directly on the front panel. Here you can name the printers uniquely by some agreed upon convention. Then using a workstation you should see it and then set it up once the system can print to it you can open the preferences and see the IP address or use IPCONFIG to see its connection.