The address your choose must be "compatible" with your network segment. In practical terms this means that the first three numbers of the IP must match those of your PC's IP. The fourth number will necessarily be different.
For example, if your PC's IP is 192.168.1.40 you can try setting your Tibbo device's IP to 192.168.1.41. Of course, you need to make sure that this IP is unoccupied. Try pinging it — if there is no response then this IP must be free.
At this point you are probably wondering about the DHCP. Isn't this the safe and convenient way to assign a valid and unoccupied IP address? Isn't it normal (common) for a network device to procure an IP while booting?
Tibbo devices are different! They boot with the default IP of 220.127.116.11. Your program can directly manipulate this IP — through the .ip property of the net. object. Should your application need to use the DHCP, we offer a DHCP library. You can easily integrate it into your next project.
Note 1: The correct IP is not required for cross-debugging to work. Even if you leave the default IP of 18.104.22.168 unchanged TIDE will be able to access your Tibbo device!
Note 2: You have to choose a suitable IP address even if you are using TiOS Simulator. The IP address of the Simulator is independent from the IP address of the PC it is running on.