Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 146)

Publication 900-UM007D-EN-E - January 2011
4-10 Parameter Adjustments & Application Considerations
Configuration of Scaling
Upper-Limits and Scaling
Lower-Limits for Analog
Input Figure 4.17
Overview
When an analog input sensor is selected, scaling to engineering units (e.g., lbs)
that match the application is possible.
Scaling is configured in the Scaling Upper-Limit, Scaling Lower-Limit, and
Decimal Point parameters (Initial Setting function group). These parameters
cannot be used when a temperature Input Type (e.g., RTD) is selected.
The Scaling Upper-Limit parameter allows you to configure the physical
quantity to be expressed by the Upper-Limit input value. The Scaling
Lower-Limit parameter sets the physical quantity to be expressed by the
Lower-Limit value. The Decimal Point parameter specifies the number of
digits to the right of the decimal point.
Figure 4.18 shows a scaling example of a 4…20 mA input, supported by
900-TC8 and 900-TC16. After scaling, the humidity sensor input can be
directly read from the controller as a percentage of humidity. However, the
display will not indicate%, only a value. The decimal point is configured one
digit to the right.
Figure 4.18 — Input Scaling
in-h
in-l
dp
Scaling Upper Limit
Decimal Point
Scaling Lower Limit
Input
(4
… 20 mA)
Readout
(humidity)
0
100%FS
20 mA
0mA
Upper-limit value (95.0%)
Lower-limit value (10.0%)