D124.1S2-Manual_EN_Rev03
2020_APR_28
7
Minimum Measuring Period
All rate measurements are based on a time interval measurement over a
(variable) number of input signal pulses. A programmable minimum
measuring period thus will be maintained, automatically including more
input pulses into every measurement with increasing input frequency.
This establishes an averaging over the programmed period of time, which
helps to stabilize the measurements, specifically with fluctuating varia-
bles. As a standard, a minimum time of 0.4 sec is recommended. A
shorter period should only be selected to trace a fast variation (by the
analog signal or alarm). A longer period however reduces the maximum
allowable input frequency, as listed below.
The parameter of P00.03 defines the minimum measuring period:of time,
with a number of steps available:
parameter minimum time max input frequency
0 =
0.03 s
100 kHz
1 =
0.07 s
100 kHz
2 =
0.1 s
100 kHz
3 = 0.4 s
100 kHz
4 = 0.8 s
75 kHz
5 = 2.0 s
30 kHz
6 = 5.0 s
12 kHz
7 = 10.0 s
6 kHz
Note:
The updating sequence for the display will be defined in a separate pro-
gram step (P02.01).
Step P00.03
minimum measuring time
Group P01.xx
Measurement Configuration
I
nput Scaling
Scaling defines the relation between the input signal frequency (in terms
of Hz), and the corresponding display (in the unit term and decimal
position as required by the application). Both values are free programma-
ble by their decimals and numerical amount. Of course, they must refer to
the same operation level. This reference point is recommended at the
high end of the intended operation range, but can be surpassed in the
later operation without error.
Example:
A signal frequency of 13250 Hz corresponds to a speed of 5000 RPM.
Program as follows:
in step P01.00
parameter 0
in step P01.01
parameter 13250
in step P01.02
parameter 0
in step P01.03
parameter 5000
General Note to the resolution:
Do not use too many decimals! If there are more decimals than justified
by the operational fluctuation of the variable, and the transmitter resolu-
tion, the minor digits in display will fluctuate accordingly.
Note:
The parameters as set on delivery, apply to 60 pulses per revolution.
Step P01.00
decimals for input frequency
Step P01.01
signal frequency at reference
Step P01.02
decimals for display
Step P01.03
speed value at reference