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4 Supplement
4.2.2 Analog input
Measured value offset
A measured value correction (offset) can be carried out to correct system specific deviations. The
offset value is added to the measured value with the correct prefix (the measured value is redu-
ced by entering a negative offset value).
Filter time constant
The filter time constant serves to adapt the digital input filter (filter of second priority). At a step
change of the input signal, approx. 26 % of the change is detected after the elapse of a time pe-
riod corresponding to the filter time constant dF (2 x dF: approx. 59 %; 5 x dF: approx. 96 %).
A high filter time constant means:
• High damping of interference signals
• Slow reaction of the actual value display to actual value changes
• Low limit frequency
4.2.3 Analog output
Zero point and end value
The factory setting corresponds to an output level of 0 ... 100 % for the continuous controller (con-
troller output 1): zero point = 0, end value = 100
If the analog output is used as controller output 2 for the 3-state controller (e.g. for cooling), the
following setting is required: zero point = 0, end value = -100
If, for example, the actual value is to be put out, which can be within the range of 150 °C to
500 °C, select the limits so that they correspond to the minimum and maximum temperature:
zero point = 150, end value = 500
CAUTION!
Measured value offset: The controller uses the corrected value for calculation (= dis-
played value). When the measured value has been offset, the corrected value does
no longer correspond to the value measured at the measuring point.
Incorrect use can cause inadmissible values of the control variable.
Only carry out a measured value offset within the admissible range.
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