Graham,
you need WMI -in TCP port 135 to be opened to allow SCS console to connect - otherwise you will get Timeout error in SCS console.
Make sure that you use right RCS server IP or FQDN.
+
you need to enable AD user of SCS console in RCS WMI Name Space and DCOM permissions on RCS -otherwise you will get Access Denied error message in SCS Console.
the best way is to use RCSutils.exe tool with /Permissions Add command.
See SCS User Guide section called User Permissions Required to Access the RCS (3.8 for SCS 11.1)
rgds
Dariusz Wittek
Intel EMEA Biz Client Technical Sales Specialist