With the Connect-Tool, your printer will be recognized without being in the same subnet (first three numbers), so the IP-Adress is not important. It could be that a firewall avoid the needed kind of communication. Is the green LED near the network connector at the printer permanently on?
Assuming that a firewall disturbs the communication between the computer and the printer, and the network adaptor at the computer is correctly set, an other possibility to set an IP-Adress ist the following:
On the printer, near to the network connector, is a label with a so named MAC-Adress. Note it.
On your PC, open the commandline tool (DOS-Window, don't know how it is named in english) and type in the following command:
arp -s <IP-Adress> <MAC-Adress>
For example
arp -s 192.168.100.5 3d-07-54-30-df-b3
The IP-Adress needs to have the same first three groups as your computer, the last group HAVE TO BE different.
After applying that command, check the connection:
ping <IP-Adress>
For example ping 192.168.100.5
You get now replies from this command, if connection timed out something is wrong with the connection, if you get replies like "reply from 192.168.100.5: Bytes = 32 Time =3ms TTL=255" you have assigned the IP-Adress correctly and could set up the software with that IP-Adress.
You could do a web-access too: if typing
http://ip-adress into a browsers adressfield, a page should pop up with information about your roland.