Flowserve 3400IQ Digital Positioner - Manual (Page 40)

Logix 3400IQ Digital Positioner FCD LGENIM3401-00 – 06/06
40
EEPROM (Electrically Erasable Programmable Read Only Memory) A device that retains data
even when power is lost. Electrically erasable means that data can be changed. EEPROM have a
limited number of times data can be rewritten (typically 100,000 to 1,000,000 writes).
Micro-controller In addition to an integral CPU (microprocessor), the micro-controller has built in
memory and I/O functions such as A/D and D/A.
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 12 = 4096
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.