The Positive Supply Rail block represents an ideal positive
supply rail. Use this block instead of the Simscape™ DC Voltage
Source block to define the output voltage relative to the Simscape Electrical
Reference block that must appear in each model.
Do not attach more than one Positive Supply Rail block to any
Dialog Box and Parameters
The voltage at the output port relative to the Electrical Reference
block ground port. The default value is 1 V.