Utility Programs - Universal Devices ISY-994i User Manual

11.10

Utility Programs

11.10.1 Averaging Using Only the Best Values
This is a program I created to stabilize inputs from more than one source. Any "wild"
sensor inputs get cut out of the calculation.
11.10.1.1Operation
• the last known working average is kept for comparison purposes during the next
iteration.
• a constant $cAVERAGE.DEV.MAX variable is set to the allowable deviation limits for
a sensor to be considered "bad". I have set mine to 2.0 degrees for this purpose
• each input is compared to the last known average and the absolute value compared
to the allowable deviation factor.
• good sensor readings are tallied and used to calculate the new average
• if all values are outside the maximum deviation then a completely new average is
created from all sensors.
11.10.1.2 Benefits
• gives a more stable resultant
• detects and isolates any sensors gone bad or "out-of-range of the crowd" readings.
• gives a contributor count that can be used for other purposes. eg: Temperature
variance detection for circulation. fan operation from indoor temperature sensors
• I have a temperature sensor mounted up under a PV array and the oven effect gets
disallowed every late morning with this program.
• this can use as many sensors as available to further stabilize the resultant output.
Just add more lines of program code.
• ISY is fast. No delays can be noticed and lots of repeats allows other processing to
occur during the calculations.
11.10.1.3 Negatives
• based on slow changing sensor values like temperature readings from thermostats
and probes. Sudden value jumps may disrupt the process.
• all three sensors outside the past average results in including all three sensors to
start. This may not be the best algorithm for some cases.
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