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Fig. 20. Trend log display (analog input)
Fig. 21. Trend log display (digital input)
200 values can be written to the local trend log memory. If the memory is full, the earliest data is overwritten with new data. The 200 most
If several datapoints are selected for the trend log, those datapoints whose value or status changes more frequently will create a larger number of values to be logged. Each change in status is logged for digital points. For analog points, there are two different types of trending: value hysteresis and
Value Hysteresis
When value hysteresis trending is selected (i.e. when the attribute "Trend Cycle" is set to 0), a new value is written to the memory when the point changes more than the given hysteresis compared to the previous value.
The default hysteresis value is 1% of the actual value, but not less than 0.2 (see also section "Trend Hysteresis" on page 22).
Example 1: The current measured value is 20°C
1 % of 20°C = 0.2°C
A new trend log value is stored at either 20.2°C or 19.8°C
Example 2: The current measured value is 9°C
A new trend log value is stored at either 9.2°C or 8.8°C
The trend can be displayed as text and as a graphic. The graphic display offers the following features:
•Simultaneous display of an analog and a digital datapoint
•
•Scrolling the time axis
•Manual
-minute display
-hourly display
-daily display
-weekly display
•Quick change between graphic and text display
Trend Cycle (V2.03.x)
With V2.03.xx firmware, it is possible to perform
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