A DOUT module is a digital output module, usually used to drive LEDs with a Midibox.

• DOUT Module ^uCApps
  
• DIN & DOUT Pintable

Note that hardware pin's will be counted D7 - D0 / O7 - O0 / QH - QA. In contrast, pins for DIN modules will be counted D0 - D7.
Refer the DIN & DOUT Pintable to see the relation between software pin numbers and hardware pins.

Check the version of your Boards; if you’re using SmashTV’s Core that’s equipped with double rows, you can build a split-cable to connect J8/J9 to a DIN and a DOUT: