Fluke VIBGUARD IIoT Commissioning page 21

Commissioning
9 Process signals
On the overview page of all online values
signals match the values from the system controller. The assignment of the channels is derived from the sensor con-
figuration page ("Sensor configuration" on page
Enter all the values in the startup report and calculate the percentage deviation as well.If the deviation is greater
than 10%, check the configuration.
The displayed values are the raw values of the respective signal such as mA for current, V for voltage and
Hz for RPM and therefore need to be converted.
E x a m p l e s f o r c o n v e r t i n g s i g n a l v a l u e s i n t o p r o c e s s v a l u e s
4..20mA signal
- Final value, generator power = 2.5 MW
- Signal value read off = 6.3 mA
- Process value calculated: 2.5 MW / 16mA * (6.3mA-4mA) = 0.36 MW
0-20mA signal
- Final value, signal value = see previous example
- Process value calculated: 2.5 MW / 20mA * 6.3mA = 0.79 MW
0-10V signal
- Final value, generator power = 2.5 MW
- Signal value read off = 6.3 V
- Process value calculated: 2.5 MW / 10V * 6.3V = 1.58 MW
Rotational frequency
- Number of trigger marks (lobes) = 5
- Frequency value read off = 28.6 Hz
RPM calculated: Revolutions/minutes = 28.6 Hz * 60 s/min / 5 = 343 RPM
E x a m p l e : C a l c u l a t i o n o f t h e p e r c e n t a g e d e v i a t i o n
Formula: <Percentage deviation> = 100% – (100% / <expected value> * <measured value>)
- (expected) value read off of the system controller: 0.39 MW
- Signal value displayed (converted): 0.36 MW
- Deviation in %: 100% - (100% / 0.39 MW * 0.36 MW) = 7.69 % < ±10 % -> o.k.
Ensure that you compare the values in the upper third of the measuring range if possible. A comparison
with very small values can lead to greater deviations due to the resolution being too low and due to signal
fluctuations!
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("Sensor test" on page 19), check whether the values of the process
17).
Edition: 10.2018