How do I get video into the 4 additional inputs? There aren’t any hardware connections for them.
There are a variety of options for getting video into the 4 additional inputs. You can add one or more TriCaster systems to your workflow, accessing the inputs from the other TriCaster system(s) over the network using NDI. NewTek is also making several NDI production apps available for purchase and for free download that allow you to input video from a variety of sources using NDI, including computers, capture cards, webcams, media files, AirSend-compatible systems and applications, and other third-party products.
It is also worth mentioning that all 8 or 12 inputs (depending on your TriCaster model) are configurable for hardware sources or networked NDI sources. This versatile feature also allows you to route the video source connected to any physical input connection to any switcher input channel.