ID
Index Name
Unit Description
507
0
ENC_CH3_Sel = 1
Encoder selection set to SINCOS(1)
514
0
ENC_CH3_Num
Encoder gearing: Numerator
515
0
ENC_CH3_Denom
Encoder gearing: Denominator
570
0
ENC_CH3_Abs
Absolute value interface selection (one-time
reading)
572
0
ENC_CH3_Lines
Number of Lines (Sin/Cos / TTL encoders)
573
0
ENC_CH3_MultiT
Number of MultiTurn bits (absolute encoder)
574
0
ENC_CH3_SingleT
Number of SingleTurn bits (absolute encoder)
575
0
ENC_CH3_Code
Code selection (SSI encoder) (binary, gray)
576
0
ENC_CH3_Mode
Mode selection (SSI encoder)
584
0
ENC_CH3_MTBase
Definition of point of discontinuity in multi-turn
range
585
0
ENC_CH3_MTEnable
Enable MultiTurn use (negative logic, 1=MToff)
586
0
ENC_CH3_Corr
Signal correction type
587
0-4
ENC_CH3_CorrVal
Signal correction values
577
0
ENC_CH3_EncObsMin
Encoder monitoring minimum, sqrt(a^2+b^2)
581
0...
ENC_CH3_AbsEncStatus
Error and status codes (absolute encoder)
582
0
ENC_CH3_PeriodLen
nm
Length of signal period (Sin/Cos linear encoder)
583
0
ENC_CH3_
DigitalResolution
nm
Length of one increment (linear absolute encoder)
580
0
ENC_CH3_Info
Encoder information
636
0
ENC_CH3_CycleCount
Sampling cycle in: n x 125 μ (microseconds)
639
0
ENC_CH3_
NominalincrementA
Sign.
per.
Nominal increment A (distance coded abs.
encoder)
631
0
ENC_CH3_
NominalincrementB
Sign.
per.
Nominal increment B (distance coded abs.
encoder)
637
0
ENC_CH3_AbsInitMode
Mode absolute value formation
Table 6.24: Parameters for channel 3 (X8) - Sin/Cos encoder
Some parameters (e.g. Sel, Num, Denom, Abs, Lines, MultiT, SingleT, CorrVal) are
self-explanatory.
The Code and Mode parameters are described in Section "SSI (cyclical) X7" on
l
P 584[0] - ENC_CH3_MTBase
= Minimum MultiTurn position
The MTBase parameter is used to set a position in the multi-turn encoder’s
travel path that defines the point of discontinuity (overflow/underflow) for the
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
85
6 Encoder
absolute value initialization (that is, the “multi-turn basis”). Assuming a
bipolar encoder measuring range, all position values that fall below
MTBase
will be shifted “up” (the whole MT range will be added to them once). This
method makes it possible to place the point of discontinuity at any point
within the encoder’s entire measuring range. By default,
MTBase
will be set
to the lowest possible value for the parameter, i.e. reliably outside of the
encoder’s value range: In this case, the full bipolar range will remain
unaffected, as values will never fall below this
MTBase
threshold (see
Section "Channel 3: Interface X8 (optional)" on page 76 as well).
l
P 585[0] - ENC_CH3_MTEnable
= MultiTurn as SingleTurn
The
MTEnable
parameter makes it possible to use multi-turn encoders as
single-turn encoders for test purposes. Negative logic: Default MTEnable = 0
means "MultiTurn-Enable ON".
l
P 586[0] - ENC_CH3_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 74).
l
P 577[0] - ENC_CH3_EncObsMin
= Encoder monitoring minimum, sqrt
(a^2+b^2)
The parameter
EncObsMin
is used to scale the Sin/Cos 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, Sin/Cos wire break monitoring will be disabled (also see Section "Channel
3: Interface X8 (optional)" on page 76).
l
P 581[0] - ENC_CH3_AbsEncStatus
= Error and status codes (absolute
encoder)
l
P 582[0] - ENC_CH3_PeriodLen
= Sin/Cos linear encoder and
P 583[0] - ENC_CH3_DigitalResolution
= linear absolute encoder
are the length of an analog Sin/Cos signal period in nanometres and the
length of a digital increment of the position from the absolute value interface
in nanometres. Both parameters are used for linear EnDat encoders (instead
of MultiT and SingleT bits (rotary)). In contrast, linear SSI encoders are
