Encoder with ProfiNet interface
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N2/N4: Velocity scaling used for PROFIdrive telegrams
The current velocity value in NIST is the share in per cent of the reference value�
The reference value can be programmed with parameter P2000�
●
N2 (NIST_A), 4000 hex corresponds to a value of 100% of the reference value
●
N4 (NIST_B), 4000 0000 hex corresponds to a value of 100% of the reference
value
●
The value range is between -200% and +200%
MSB = 1 corresponds to a negative sign
MSB = 0 corresponds to a positive sign
9.5.12 Velocity filter
The velocity value can be used with three different exponential moving average
filter types�
Parameter
Meaning
Data type
Velocity filter
Parameter selection: fine, normal, coarse
Integer 32
Ratio between old and current velocity:
– Fine: 7:3
– Normal: 96:4
– Coarse: 996:4
9.5.13 Endless shaft (round axis)
Normally the "total resolution" / "measuring units per revolution" must be an
integer and the total resolution must fit an integer number of times into 8192 for an
encoder with 13 bits per revolution� This means that e�g� 100 or 325 revolutions
could cause troubles�
So the following equation must apply:
(4096 x measuring units per revolution) / total resolution = integer
But the ProfiNet encoder solves this problem automatically� The encoder checks
whether the parameters need the endless shaft and activates this functionality
independently�
The internal software routine only works if the encoder is in operation� If it is necessary to turn the
encoder shaft more than 1,024 revolutions without power supply this can lead to problems (the
internal routine will not work without power supply)� With this function there will be saved additional
values in the internal EEPROM�
