P No.
Index
Name / Settings
Unit Description
0
ResExc
us
Exciter signal phase shift
Delay
us
Compensation for commutation angle
delay
566
0
ENC_CH2_Amplitude
±
Correction of amplitude for cable lengths >
50 m (only after consultation with KEBA ).
567
0
ENC_CH2_EncObsAct
Amplitude of analogue signal
Table 6.16: Encoder configuration channel 2 (X6) parameters (continue)
The Sel and Lines parameters are self-explanatory.
Other parameters, such as Num and Denom, are described elsewhere (see Section
"Encoder gearing X6" on page 77).
l
P 561[0] - ENC_CH2_Corr
= Signal correction type
The GPOC routine used for track signal correction purposes for sine/cosine
signals is used to compensate for systematic errors. The routine is controlled
with the
Corr
and
CorrVal
parameters (see Section "Signal correction GPOC
(Gain Phase Offset Correction)" on page 75).
l
P 563[0] - ENC_CH2_EncObsMin
= Encoder monitoring minimum, sqrt
(a²+b²)
This parameter is used to scale the resolver and SinCos wire break
monitoring and represents the “downwards threshold” for an error message.
The default setting is 0.2, corresponding to approx. 20% of the track signals’
amplitude (approx. 80% corresponds to approx. 1 Vss). If
EncObsMin
is set
to 0, the resolver and SinCos wire break monitoring will be disabled (see
Section "Channel 1: Interface X7" on page 59 as well).
6.6.1 Compensation for long resolver cables
When using long resolver cables, there will be a phase shift between the controller’s
exciter output signal and the controller’s A/B track input signals (B: S1-S3, cos and A:
S2-S4, sin). This phase difference can be compensated for with P 565[0] - ResExc:
ResExc is the time, in µs (microseconds), by which the resolver excitation will lead.
Moreover, P 565[1] - Delay can be used to compensate for a commutation dead
ID No.: 0842.26B.5-01 Date: 09.2020
ServoOne - Device Help
75
6 Encoder
time, which can become important in the case of higher rotating field frequencies.
When there is an absolute reduction in signal strengths (amplitudes) as a result of
the long cables, P 566[0] - ENC_CH2_Amplitude can be used to subsequently
increase these amplitudes (up to a max. of +10.5%) so that a drive signal level of
80–85% for signals A and B is once again attained. This is achieved by adjusting the
resolver excitation amplitude. Parameter P 567[0] - ENC_CH2_EncObsAct can be
used to check the effects of adjusting the compensation settings. It returns the length
of the phasor for signals A and B (sqrt(a²+b²)) and is accordingly a measure of “the
amplitude” of signals A and B: If the phase shift is properly corrected at the end of the
compensation adjustment process, you can save the settings.
NOTE
l
This function is not available for the ServoOne junior.
l
Do not use cable lengths > 50 m without first consulting with KEBA
.
6.6.2 Signal correction GPOC (Gain Phase Offset Cor-
rection)
The resolver and SinCos incremental encoder demonstrate systematic errors that
are reflected in the measured position and in the speed calculated from this (gain
and phase errors, offset components of the tracking signal). The GPOC method for
track signal correction compensates systematic errors. GPOC is available for
encoder channels 1 and 2.
