Issue
A newly created lookup table for a Sigma Analogue Output (AO) object was designed to provide output in 10% increments. However, the object continues to display values in 1% steps.
Product Line
Satchwell BAS & SigmaEnvironment
Sigma Controller (All Versions)
Cause
The AO object uses its value as the input to the lookup table. The output from the lookup table is then passed to the Digital-to-Analog (D/A) converter, which drives the physical output. However, the Sigma front end displays the AO object’s input value—not the processed output from the lookup table—resulting in the appearance of 1% steps.
Resolution
To display the processed output value (i.e., the result of the lookup table) on the Sigma front end, a programmable object must be used. This object will apply the lookup table to the input value and then reference a standard AO object for output.
Example of a Programmable Object Configuration
10 XFLO = POINT 0|51
20 YFLO = LOOKUP (1812, XFLO)
30 RETURN VIA TEXT 92 VALUE YFLOPOINT 0|51: The control/input object1812: The lookup table numberYFLO: The processed output value to be displayed
Verification
To confirm the output value:
- Use a multimeter connected to the physical output of the AO object.
- Ensure the programmable object is correctly configured to reflect the desired output steps.
