This unit has an internal supply that isolates supply voltage from the internal power. The unit operates correctly from 12-24 VAC or 10-34 VDC (<75ma at +28 VDC, <150ma at +12 VDC). Units are equipped with full wave rectification on the power front end, so power may be applied to Pin 1 & 5 using either polarity. The power connector is a 9pin Sub-D.
The package for this unit consists of a solid epoxy block. The internal electronics are assembled and tested before the encapsulation process. During the encapsulation the printed circuit board(s) are placed in a five sided box made of RTV mold parts. The cavity is filled with epoxy and the lid (top) of the mold is inserted. The curing process takes 24 hours. This type of package seals the electronics so water and contamination cannot affect the internal electronics. This type of package also provides superior resistance to shock and vibration compared to a metal or plastic box enclosure.