Kübler SMC1.3, Safety Manual

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R60047.0002 - Index 2 EN – page 53 / 115
9.8 Divergence Parameters
The parameter “Div.Mode” defines the type of comparison: Frequency Comparison or
Position Comparison. The setting of this parameter affects only the error detection.
If the frequency ratio cannot be adjusted accurately, do not use the Position Comparison
caused by cumulative position increments. If the encoders slip, Frequency Comparison
has to be preferred.
At SMC1.3 the position comparison can generally be used, since only one encoder is
connected here.
No. Parameter Remarks
003 „Div. Mode“ Type of comparison of encoder inputs
004 „Div. Switch %-f” Frequency threshold
005 „Div. %-Value” Percentage of frequency deviation above the Div.Switch %.
006 „Div. f-Value” Absolute frequency deviation (Hz) below the Div. Switch %-f
threshold
007 „Div. Calculation” 0
008 „Div. Filter” Filter (OFF = 0, MEDIUM = 5, HIGH = 10)
009 „Div. Inc-Value“ Max. incremental deviation
Divergence parameters are relevant even for the SMC1.3 devices,
since also with only one SIL2 encoder frequency or position is splitted
into two channels, where asynchronism during changes of the
frequency may cause frequency divergence. Using SMC1.3 position
deviation has to be preffered.
9.8.1 Frequency comparison:
These parameters defines the maximum permissible frequency deviation between
sensor 1 and sensor 2, based on percentaged values of Div Calculation. Parameter Div.
Switch %-f defines the frequency threshold below which deviations are taken as
absolute values, and above which deviations are taken as percentage. When the
absolute difference of frequencies exceeds the setting of Div. f-Value below the
threshold setting, a frequency error will be triggered. When the percentaged difference
exceeds the setting of Div. %-Value above the threshold setting, also a frequency error
will be triggered. Parameter Div. Filter provides an option for suppression of short-
duration errors.
1. The facility of setting a frequency threshold provides suppression of possible
frequency errors caused by jerking in the startup phase.
2. The threshold setting must be below the lower switchpoint setting (underspeed
or frequency band).
3. It is an individual issue of the actual application to fix the deviation values under
normal operating speed and under startup conditions that should trigger a
frequency error signal.