Nematron Pointe Controller - Manual (Page 92)

Chapter 4: System Design and Installation Pointe Controller User Guide
90
via a switching power converter and a transformer. There are OptiLogic analog
input modules in both categories. Neither is functionally superior to the other.
The on-board power generation may save the cost of an additional external
power supply.
The other aspect of isolation is the fact that the measured value must be
transmitted from the analog to digital converter, operating on one power supply,
to the main system, which is operating on another power supply. This is
commonly accomplished through optical isolators.
Resolution
Resolution is the number of significant bits of information the A/D converter uses
to express the value of the measured input. A 12-bit A/D converter uses 12 bits of
information, meaning the entire range is covered by a number between 0 and
(2
(12) -1) or 0 to 4095. A 14-bit A/D expresses the same range as a number
between 0 and 16,383. In other words, the more bits used, the finer the
increment. In general terms, the higher the resolution, the better.