Introduction

'Clocking' is when a meter goes around the clock, ie it gets to a reading of 9999 and then goes back and starts again from 1.  It can cause an issue when a reading lower than the previous reading is added.  Sigma then calculates high consumption as it assumes it has gone round the clock.

Note, this process is the same for Periodic or Non Periodic Channels that are set to Meter Readings (not Values), ie where incremental Meter Readings are added to the Channel.

Checking the Channel Set Up

The standard set up for a Channel that records Meter Readings is as follows:

• Right click on the Channel > Edit

• Expand the Advanced Measurement Settings section

Note: If the Clocking Threshold (CTF) is set at 100%, the Meter will always clock when the Present Reading is less than Previous Reading

Channel Editor Settings 

Note:  The above Channel is set to Meter Readings  and has a Maximum Value added (ie the number of digits in the Meter Reading) and Clocking Threshold of 100%, so Sigma will check if the Meter clocks.  

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Viewing the Channel Data 

In the example below, the reading for 3rd of November is lower than the previous reading, ie has gone from a Reading of 100, round the clock to 99999 (the figure in the Max Value) and then up to 91.

This causes a spike in consumption as Sigma assumes the meter has clocked.

This would show a consumption of 99,981 (as the Maximum Value set in the Channel is 99999)

• From the Channel Editor > click Edit Data

There is a total advance of 25 for the period  (because of the negative reading): 120 (Present Meter Reading)  -  95 (Start Meter Reading) = 25.

 But the spike in consumption affects the profile (and reporting), 

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Energy Intelligence Report

If you then run a report on the Consumption, it will not be a true reflection.

From Energy Intelligence, run the General Graph and Table for Metered Consumption Report:

The daily consumption shows as 49,995 on 1st and 2nd November, with a total consumption of 100,024

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Adjusting the Settings

To overcome the spike, you can lower the Clocking Threshold to 90% (for example).

• Right click on the Channel > Edit

• Set the Clocking Threshold, to 90  (90%)

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With the Clocking Threshold set at 90% (0.9), the reading of 91 on 03/11/22 would be within the acceptable threshold and would treat that as a negative value, not a clocked value, meaning a small dip in consumption, but not a large spike

• 90 (the Clocking Threshold) / 100 (the previous reading) = 0.90    91 present reading) / 100 (previous reading) = 0.91.     0.91 is greater than 90%  (.90), The reading on 90 is treated as a negative value, not a clocked value

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Re running the Energy Intelligence Report

After changing the sessions (and refreshing Energy Intelligence), rerunning the Report will give the following:

• The daily consumption does show as negative on 1st and 2nd November, but the total consumption for the period is 25 (which is correct)  - a much better report than if the Clocking Threshold was 100%

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Examples when Clocking Threshold is set to 90%

Present Reading is Higher that the Previous Read

Present Read (120) is more than the Previous Read (91)

• Sigma calculates the consumption: 120 (present read) - 91 (previous read) = 29

  • An advance of 29

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Present Reading is Less that the Previous Read, within the Clocking Threshold

Present Reading is 100 and Previous Reading is 91

• Sigma calculates the consumption: 100 (present read) - 91 (previous read) = -9 (negative consumption)

  • As the consumption appears negative, Sigma checks if it is within the Clocking Threshold

    • 90 (Clocking Threshold) / 100 (Previous Meter Reading) = 0.90  x 100 = 90     

  • As the difference is  -9  (less than 90%) (the clocking threshold)

    • Sigma calculates a negative consumption of -9