The Sensor Master can connect to 12x 5v powered digital or analog sensors with the 3-pin structure signal, power and ground (see: Using the Sensor Input channel)
We recommend you watch the Sensor Master Tutorial
To connect sensors to a Sensor Master, you will need:
To connect any 5v sensor to the Sensor Master, screw the stripped wires into the RJ45 Breakout as above
To patch this channel to a digital input in COGS software see: Patching channels to the Motor Master
If the sensor requires a 5v powered counterpart (e.g a laser or an IR beam), these can be connected to a sensor channel in the first two screw terminals, and missing off the signal line. You won't be able to use this channel as an input, it will just power the device constantly.