A multi-bit digital to analog converter is implemented by a switched-capacitor arrangement in which a reservoir capacitor accumulates charge representing the desired analog output signal. Power is inductively coupled from a primary coil to a device containing a secondary coil. The archway allows the fence system to be easily installed by sliding the open end of the archway over a suspended feedwater pipe. At least one monitor display may be operably coupled to the door system controller and configured to display information regarding the operational parameter of the input devices.