Rockwell Automation T3480 ICS Regent Guarded Analog Output Modules - Manual (Page 16)

Guarded Analog Output Modules (T3480)
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Industrial Control Services
Programming
Outputs are controlled by writing application programs that
solve for output values. For example, placing an output tag
name in the result field of a math element in ladder logic will
set the analog output to the value calculated by the math
element. Note that the data range for analog outputs is 0 to
4095 corresponding to the output current rage of 4 to 20 mA.
Often you may choose to write analog control logic using an
engineering unit number range other than 0 to 4095 to
simplify the creation and interpretation of the control logic. If
you do so you should use the analog scaling function block to
“unscale” your calculated value to the 0 to 4095 range
required for the analog output. An example of an analog
scaling entry for analog outputs is shown in Figure 10.
Figure 10. Unscaling an Analog Output.
This example implies that some other control logic solves a
value for the shared register “AO1_ENG_VAL” which ranges
from 0 to 10,000 (the low and high values). The analog
scaling entry shown in the example then converts the
engineering unit value to the analog output range of 0 to
4095, storing the converted value in the analog output “AO1”.
By using an engineering unit range of 0 to 10,000 for your