Rockwell Automation 2085 Micro800 Discrete and Analog Expansion I/O Modules - Manual (Page 21)

Rockwell Automation Publication 2080-UM003A-EN-E - March 2013 13
Discrete and Analog Expansion I/O Features Chapter 2
Convert Analog Value to Data Format Value
The formula for converting an analog value x to a data format value y, or
converting data format value y to analog value x, is as follows:
Y = ((X - Minimum Value of X Range)*(Range of Y)/(Range of X)) +
(Minimum Value of Y Range)
Example:
Find the temperature value Y of thermocouple type K when the Raw/
Proportional Data X is -20000.
Given:
X = -20000 (Raw/Proportional Value)
Minimum value of X Range = -32768 (Minimum value of Raw/
Proportional Data)
Range of X = 32767 - (-32768) = 65535 (Range of Raw/Proportional
Data)
Range of Y = 1372 - (-270) = 1642 (Range of Thermocouple K in °C)
Minimum value of Y Range = -270 °C (Minimum value of Thermocouple
K)
Then:
Y
= (-20000 - (-32768))*1642/65535 + (-270 °C) = 49.9 °C
Valid Range of the 2085-IRT4 Data Formats
Data Format Sensor Type – Temperature
(10 Thermocouples, 8 RTDs) Sensor Type
0…100 mV Sensor Type
0…500 ohms
Raw/Proportional Data
(1)
(1) See Convert Analog Value to Data Format Value on page 13 .
-32768…32767
Engineering Units x 1 Temperature Value
(3)
(°C/°F)
(3) The resolution is 0.1 °C/°F per count. For example, 999 here means 99.9 °C/°F (or 999 x 0.1 °C/°F). The range
depends on the selected sensor type.
0…10000
(5)
(5) The resolution is 0.01 mV per count. For example, 9999 here means 99.99 mV (or 9999 x 0.01 mV).
0…5000
(7)
(7) The resolution is 0.1 ohm per count. For example, 4999 here means 499.9 ohm (or 4999 x 0.1 ohm).
Engineering Units x 10 Temperature Value
(4)
(°C/°F)
(4) The resolution is 1 °C/°F per count. For example, 999 here means 999 °C/°F (or 999 x 1 °C/°F). The range
depends on the selected sensor type.
0…1000
(6)
(6) The resolution is 0.1 mV per count. For example, 999 here means 99.9 mV (or 999 x 0.1 mV).
0…500
(8)
(8) The resolution is 1 ohm per count. For example, 499 here means 499 ohm (or 499 x 1 ohm).
Percent Range
(2)
(2) The resolution is 0.01% per count. For example, 9999 here means 99.99% (or 9999 x 0.01%). See Convert
Analog Value to Data Format Value on page 13 for the conversion method.
0…10000