Nikon used to have a USB Mass Storage mode on its cameras that would allow it to mount the card straight to your filesystem from within the camera. They no longer include this feature as it's now recommended that you use a Card Reader with DSLRs since they provide a fast and reliable way to transfer your data without having to plug your camera into a computer. In effect, you will need to start using a Card Reader as Kirk has mentioned in order to use Ingest with your D7100. The reason it does not work is because the camera now connects as a Device rather than a Disk and we do not have support for Ingest from a non-mountable location.
Screen shot is of a Nikon D100 Setup Menu showing the USB Mass Storage option. Nikon no longer supports this feature in its cameras.
[attachment deleted by admin]