12.2.3.4 Evaluaon of the signal quality
Signal quality
The signal quality is evaluated by the parameter 0x2C52:004, which ser
ves to monitor the ini-
al reading and seng of the posion.
If a transmission error occurs
•
the curr
ent angular dri is marked as invalid in the parameter , bit 9.
•
the in
verter keeps its operang status.
Angular dri
Communicaon with the encoder is no longer monitored during the angular
dri
determinaon.
The value displayed in 0x2C52:003 is de
termined in dierent ways depending on the encoder
type:
•
Determinaon of the current angular dri for the sin/cos encoder
In the case of an incremental SinCos encoder, the pulses between two zero pulse events of
the Z-track are counted. Assuming that there are no faults, this value corresponds to the
set number of increments. The accuracy of this process corresponds to ± 1 increment grad-
uaon of the encoder, with the dierence between the set number of increments and the
counted pulses being converted to an angle with an accuracy of ±0.1°. The disadvantage is
that an updated angular dri value only becomes available at the end of a complete
encoder revoluon. In turn, this means that the update rate depends on the speed.
•
Determinaon of the current angular dri for the SinCos-Hiperface® absolute value
encoder
In the case of a SinCos absolute value encoder with HIPERFACE® protocol, no Z-track is
available; instead, the posion is regularly read out of the encoder. When the rst encoder
read-out operaon is performed (aer power-up or eliminaon of wire breakage), the
encoder posion is used to inialise the internal device counter unit and to set an internal
device posion. All other read-out processes from the encoder are used to generate a dif-
ference between the internal device posion and the encoder posion. Assuming that
there are no faults, the dierence is zero. However, the dead me of the communicaon
with the encoder means that the accuracy of the process is dependent on the speed and
therefore restricted compared to the zero pulse process. However, the advantage is that
the update rate does not depend on the speed, but is instead only determined by the com-
municaon rate. The update rate is encoder-specic and is generally in the range between
30 ... 50 ms.
Parameter
Address Name / seng range / [default seng] Info
0x2C52:003 Load encoder/master encoder sengs (encoder):
Angle
dri
•
R
ead only: x.x °
Display of the angular dri of the current angle error.
0x2C52:004 Load encoder/master encoder sengs (encoder):
Actual amplitude signal quality
•
R
ead only: x %
The signal quality indicates the actual amplitude of the SinCos analog
signals with regard to 1 Vss = 100 %.
•
The signal quality should be between 95 ... 105 %.
•
There is no need for opmisaon if the signal quality is within the tol-
erance zone for the analog encoder signals given in the data sheet of
the encoder manufacturer.
Conguring the feedback system
Sec
ond feedback system for the techology applicaon
Encoder sengs
198