Choose a parameter for stepper output in the configurator and select the stepper controller output number for it. If your gauge has an initial position sensor, mark the "Position Sensor" checkbox when configuring it (for 360-degree rotation gauges it is set as default).
Any stepper gauge can be "linked" with any electric bus and make it work dependant on this bus voltage. For example you gauge may stop working (and be moved to the zero position) if the bus voltage drops below assigned value.
You can assign two parameters for output to one particular stepper gauge and make it dependant on some input (switch) state or specific parameter value. For example you gauge may show voltage from different sources.
Before using the "sectoral" stepper driven instrument in the cockpit you need to calibrate it. Use the convenient Calibration Tool in the SimVimX plugin to correctly map the data value range on the gauge dial.
! No calibration is needed for continuous (full-circle) rotation instrument. Just assign it and start your plane!