Hide thumbs Also See for S7-1200:
Table of Contents
Example (LAD): normalizing and scaling an analog input value
An analog input from an analog signal module or signal board using input in current is in the
range 0 to 27648 for valid values. Suppose an analog input represents a temperature where
the 0 value of the analog input represents -30.0 degrees C and 27648 represents 70.0
degrees C.
To transform the analog value to the corresponding engineering units, normalize the input to
a value between 0.0 and 1.0, and then scale it between -30.0 and 70.0. The resulting value
is the temperature represented by the analog input in degrees C:
Note that if the analog input was from an analog signal module or signal board using voltage,
the MIN value for the NORM_X instruction would be -27648 instead of 0.
Example (LAD): normalizing and scaling an analog output value
An analog output to be set in an analog signal module or signal board using output in current
must be in the range 0 to 27648 for valid values. Suppose an analog output represents a
temperature setting where the 0 value of the analog input represents -30.0 degrees C and
27648 represents 70.0 degrees C. To convert a temperature value in memory that is
between -30.0 and 70.0 to a value for the analog output in the range 0 to 27648, you must
normalize the value in engineering units to a value between 0.0 and 1.0, and then scale it to
the range of the analog output, 0 to 27648:
Note that if the analog output was for an analog signal module or signal board using voltage,
the MIN value for the SCALE_X instruction would be -27648 instead of 0.
Additional information on analog input representations (Page 916) and analog output
representations (Page 917) in both voltage and current can be found in the Technical
Specifications.
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
Basic instructions
7.7 Conversion operations
253
Table of Contents
loading

Table of Contents