I set the IP address on my new device and can no longer access it, what do I do?

This is normal operation. When setting up a unit for the first time, the unit has a default IP address of 192.168.123.123. When you change this IP, the 192.168.123.123 address is no longer valid and the device and the computer connected to it are no longer on the same network. To communicate with the unit, reconfigure the computer to be on the same IP subnet as the device, or connect it to the network and access it from a network connected computer.