3-26
Chapter 3: Configuring the 2085-IT8-SC/IT-16-SC Using CCW
User’s Manual Pub. 0300322-01 Rev. A
This configuration setup has no effect if the channel is selected to run millivolt
measurement or a non-Engineering Unit Data Format is used.
If the input channel is configured to use Fahrenheit units, its Channel Fault and
the Over/Under Range status bits will be set in the input table if:
•
The final display value is equal to, or goes beyond, the Data Type limits
(-32768/+32767) before reaching its minimum or maximum point of the
Input Type range or vice versa.
•
Once the above condition happens, the display value will stay at the data
limit.
3.6.6
CJ Sensors
Both 2085-IT8-SC and 2085-IT16-SC modules have two CJ Sensors located at
the two-column terminal block. Each sensor’s valid working range is from -20 ºC
to +90 ºC. The temperature reading is measured by the 12-bit resolution ADC on
the main processor.
The Data Type in the input table used to display the CJ Sensor reading is a signed
16-bit integer. The valid range is scaled down at -2000 to +9000, indicating its
resolution up to two decimal places in Celsius units. The sensor limits are set to
the same as the minimum and maximum points of the sensor range.
Range points and limits for the CJ sensors are listed in the following table:
CJ Sensors
Range
Condition
EU×1
ºF
°C
ºF
°C
194 ºF
90.00 °C
High Limit
19400
9000
194 ºF
90.00 °C
High Range
19400
9000
-4 ºF
-20.00 °C
Low Range
-400
-2000
-4 ºF
-20.00 °C
Low Limit
-400
-2000
The data format for displaying the CJ Sensor reading is not configurable. EU×1
format and Celsius units are used for scaling the CJ Sensor reading.
Each sensor has its own status bits to indicate fault in the input table. Below are
the cases on handling CJ Sensor faults for Cold Junction Compensation to
continue.
