Hi,
As I understand your question you cannot see NI-IMAQ in Software on the myRIO-1900. It should be possible to select NI-IMAQ when selecting software for the myRIO as long as you have Vision Acquisition Software installed on your development computer. Also, it is expected behavior for the camera to be listed under devices as it is a physical device. Below I've provided a few resources that may be helpful for you as you continue working.
http://www.ni.com/pdf/manuals/376047a.pdf
http://forums.ni.com/t5/Academic-Hardware-Products-ELVIS/myrio-IMAQ/td-p/2935318
I hope you find this information helpful; have a great day!
- Kale
