Thanks for responding Luke
Unfortunately after following the instructions I still only get options for HD no SD resolutions appear.
All SDI in put and output connections are going through channel A.
Also in the BlackMagic DeckLink preferences under the Change Video and Audio Connections, I only see two options for output:
SDI & NTSC/PAL & Y,R-Y,B-Y and SDI & NTSC/PAL & S-Video
However the manual says that it should be set to a third option