How to disable video input loop to video output in DL Quad

I'm using a DeckLink Quad. When i plugin camera into SDI input 1, the video signal loop into SDI output 1. So I can't not open SDI output 1 to display anything.
I was code
IDeckLinkConfiguration::SetInt(bmdDeckLinkConfigCapturePassThroughMode, bmdDeckLinkCapturePassthroughModeCleanSwitch);
but It return E_FAIL.
Anybody an help me
Thanks

Hi,

each channel of the DeckLink Quad can only act as an input OR an output, not both, so if you are capturing, you cannot also play back.

The failure to set bmdDeckLinkConfigCapturePassThroughMode indicates that the board does not support the bmdDeckLinkCapturePassthroughModeCleanSwitch feature, which was introduced on more recent devices.

cheers