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SCU-138-P-2230
5.3.3
SYS_RANGE (Working range)
Command
Parameter
Unit
Group
SYS_RANGE X
x= 200… 8000
Hz
STD
This command defines the nominal working range, which corresponds to 100% of the input signal. This value
is in relation to the sensor working stroke (FMAX). Wrong parameterization causes wrong system settings.
The control parameters cannot be calculated correctly in case of wrong values.
It has to be considered that instead of a rotational speed in [rpm] the module measures the frequency of the
input signal. If multiple pulses are triggered per revolution, here a value has to be entered which is accordingly
higher.
Example: Desired Speed at 100% is 1500 rpm.
Per revolution 30 pulses are produced. f
Setp
= 1500 rpm * (min. / 60 s) * 30 = 750 Hz.
This value has to be entered in SYS_RANGE.
5.3.4
PWM:ZERO (scaling of the PWM input)
5.3.5
PWM:FULL
Command
Parameter
Unit
Group
PWM:ZERO
x= 0… 10000
0,01 %
PWM
PWM:FULL
x= 2000… 15000
0,01 %
PWM
These values are used to calculate the speed / frequency setpoint on the basis of the read in duty cycle of the
PWM input.
These parameters are
only visible and operational if the setpoint source “PWM” is selected via the parameter
SELECT:W.
The factory setting 0 / 10000 yields a proportional behaviour and 100% setpoint if the duty cycle is 100% that
means a permanent signal. This is only a theoretical value because a permanent signal means the absence of
pulses and therefore the pulse width cannot be evaluated.
The calculation of the command value is accomplished according to this formula:
WA = (DC
– PWM:ZERO) / (PWM:FULL - PWM:ZERO) * 100%
The range (PWM:FULL - PWM:ZERO) must not be defined too small because otherwise the resolution of the
signal will be bad. Therefore an internal limitation of PWM:FULL is active which will set this parameter to at
least PWM:ZERO + 2000 (+ 20%). This means lower values cannot be entered.
5.3.6
FIX_SPEED (Internal demand value)
Command
Parameter
Unit
Group
FIX_SPEED X
x= 0… 10000
0.01 %
STD
The intern
al setpoint is activated if the parameter SELECT:W is set to “PRE” (preset). In this case, the com-
mand input is disabled and the value specified here is used as demand value. This function can be used,
whenever the driven equipment should be operated at a constant speed.
