How can I check if NIS is blocking comms between my PC and my Brother wireless printer?

My printer is showing as 'offline' but it's not. It's a Brother DCP-J315W wireless model.

 

I've uninstalled and reinstalled the drivers/software so it shouldn't be that.

Error messages and a FAQ search on the Brother site all suggest that my firewall is blocking communications between the printer and my PC.

 

When I get to the final stage of the installation where it's supposed to bring up a list of available printers installed, the list if blank and even a manual search etc fails.

 

So how can I check if NIS is blocking comms between my PC and my Brother wireless printer?