Flowserve Logix 3400MD User Instructions page 24

Logix 3400MD Digital Positioner FCD LGENIM3404-00 – 9/09
Microprocessor Semiconductor device capable of performing calculations, data transfer, and logic decisions. Also referred to as CPU (Central Processing
Unit).
Protocol A set of rules governing how communications messages are sent and received.
Resolution Resolution is a number which indicates the smallest measurement which can be made. You will often see analog-to-digital (A/D) converters
referred to as a 10-bit A/D or a 12-bit A/D. 10-bit and 12-bit are terms which indicate the total number of integer counts which can be used to measure a
sensor or other input. To determine the total integer count, raise 2 to the power of the number of bits.
Example: 12-bit A/D
Total integer number = 2
Number of Bits = 2 = 4096
12
Resolution is the measurement range divided by the maximum integer number.
Example: A valve has a 2-inch stroke and a 12-bit A/D is used to measure position.
Resolution = Stroke/(Maximum Integer for 12-bit) = 2 inch/4096 = 0.000488 inches
Sampling Taking readings at periodic time intervals.
Serial Channel Channel that carries serial transmission. Serial transmission is a method of sending information from one device to another. One bit is sent
after another in a single stream.
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