This board is designed to make it very easy to control Motors and Servos without any extra hardware as well as giving you the ability to switch your Raspberry Pi on and off and power it from AA batteries. See here for further info on all its capabilities.
Servo control is done through variables Servo1 and Servo2 (or you can use Tilt or Pan instead).
The servo1 accepts values from -60 to +60 degrees (to avoid jamming issues if used as a tilt servo) and servo2 accepts -90 to 90.
The board has two un-buffered 3.3V inputs and their values show up in as sensor blocks input1 and input2
If Ultrasonics are connected to inputs 1 or 2 as per this then they are referred to as Ultra1 or Ultra2
There are also two 5V outputs and these are can be controlled using variables Output1 or Output2 or broadcast Output1On for instance.
The two inputs can also be used as 3.3 un-buffered outputs if required and referred to as Input1 or Input2