You can manually set the IP address of an FC switch or any other interconnect in a HPE blade chassis.
Just launch Putty connect to the active onboard administrator then enter:
connect interconnect interconnect position
connect interconnect 2
This is like connecting to the switch with a serial cable and will allow you to logon.
Then once logged on just set the IP address like normal:
View current IP address settings:
SWITCH Ethernet IP Address: none Ethernet Subnetmask: none Gateway IP Address: none DHCP: O
Set IP address: