Nissin Di622 with Nikon D3000?

How do i get my Nissin Di622 to work off camera with my Nikon D3000? It says it should work but it doesn't want to work i don't understand why, if anyone knows any help would be greatly appreciated

Added (1). Sorry i do mean the optical slave is not working

According to the specs this is a shoe mount flash. Unless you have a way to connect the two when the flash is off camera, wireless or wired, how can you expect it work?

If the Nissin is an iTTL flash, you can't use it off camera with your D3000 as a flash controller.

You need radio triggers, or cables, to make it work. The Nikon SC-28 or SC-29 off camera shoe cords allow about 3' of distance with full iTTL control. Radio triggers do not allow any control but triggering, so you have to set the flash manually.

This is not a fault of the flash, your camera can't control any flash off camera. It can trigger an optical slave flash, if you can get the flash to work with the pre-flash metering.

Can you tell me under what conditions were you trying to use the optical slave?

Even under moderate light optical triggers can't tell the difference between the flash being fired from the ambient light unless the flash is very near to the camera. So you need to be quite specific about the lighting setup.

Simple answer, you're not going to. D3000 doesn't feature a commander., you'll need a d90 or better