This read-write object sets the output voltage level used specifically for the digital signal type on this IRIG output unit port, per its description limiting it to digital output ports. Admins tune this voltage to match what the connected digital timing receiver expects, since a mismatched level can prevent reliable decoding of the time code. For example, if a newly connected digital IRIG receiver fails to lock onto the signal, an admin would check and adjust this voltage setting to match the receiver's input specification.