Allen-Bradley MicroLogix 1200 User Manual page 37

The engineering units data formats represent real
TIP
engineering temperature units provided by the
module to the controller. The raw/proportional
counts, scaled-for-PID and percent of full-scale data
formats may yield the highest effective resolutions,
but may also require that you convert channel data
to real engineering units in your control program.
Raw/Proportional Data
The value presented to the controller is proportional to the selected
input and scaled into the maximum data range allowed by the bit
resolution of the A/D converter and filter selected. The
raw/proportional data format also provides the best resolution of all
the data formats.
If you select the raw/proportional data format for a channel, the data
word will be a number between -32767 and +32767. For example, if a
type J thermocouple is selected, the lowest temperature of -210°C
corresponds to -32767 counts. The highest temperature of 1200°C
corresponds to +32767. See Determining Effective Resolution and
Range on page 3-14.
Engineering Units x 1
When using this data format for a thermocouple or millivolt input, the
module scales the thermocouple or millivolt input data to the actual
engineering values for the selected millivolt input or thermocouple
type. It expresses temperatures in 0.1°C or 0.1°F units. For millivolt
inputs, the module expresses voltages in 0.01 mV units.
Use the engineering units x 10 setting to produce
TIP
temperature readings in whole degrees Celsius or
Fahrenheit.
The resolution of the engineering units x 1 data format is dependent
on the range selected and the filter selected. See Determining Effective
Resolution and Range on page 3-14.
AB Parts
Module Data, Status, and Channel Configuration
Publication 1762-UM002A-EN-P - July 2002
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