6.5.4.2 Sin/Cos encoder
Ch1: SINCOS(1) - Sin/Cos signals
Sin/Cos encoders can...
a. Be pure incremental encoders
without
an absolute value interface. In this
case,
P 540[0] - ENC_CH1_Abs
must be set to OFF(0).
b. Be incremental encoders
with
an absolute value interface. In this case,
P 540
[0] - ENC_CH1_Abs
must be accordingly set to SSI(1), EnDat(2), HIPER(3)
or, in special cases, SSI_CONT(4) so that it will be possible to read the
absolute encoder position for the absolute value initialization routine once
during the initialization phase.
6.5.4.2.1 Pure Sin/Cos incremental encoder
To run these encoders as purely incremental encoders with a zero pulse on encoder
channel Ch1 (without an absolute value interface), the approach is basically the
same as for pure TTL operation (see Section "TTL encoder" on page 60). The same
parameters apply.
However, there are the following differences:
a. There are no different signal types for the Sin/Cos signal (always 1 Vss for
cosine and sine).
b. The zero pulse is the analog zero pulse typical of Sin/Cos encoders (see the
“Connection for high-resolution encoders” section in the Operation Manual
MSD Servo Drive Single-Axis System, for example).
6.5.4.2.2 Linear Sin/Cos incremental encoder
Linear Sin/Cos encoders are operated as rotary encoders. For linear motor
operation, P 542[0] - ENC_CH1_Lines and the encoder gearing (see Section
"Encoder gearing" on page 87) are used to establish the ratio for the linear motor’s
pole pair subdivision (North-North) for commutation. 1 x North-North corresponds to
MOOG
ID
No.:
CB40859-001
Date:
02/2018
MSD Servo Drive - Device Help
62
6 Encoder
one revolution from Lines. In this case, the motor pole pair number must be set to 1.
Moreover, P 553[0] - ENC_CH1_PeriodLen is not used in this case.
6.5.4.2.3 Signal correction (GPOC)
The GPOC (gain phase offset correction) routine used for track signal correction
purposes for sine/cosine signals is used to compensate for systematic errors. The
routine is controlled in encoder channel Ch1 with P 549[0] - ENC_CH1_Corr and
P 550[0] - ENC_CH1_CorrVal. For details see Section Signal correction GPOC
(Gain Phase Offset Correction)" on page 71
6.5.4.2.4 Sin/Cos incremental encoder with absolute value
interface
The following table lists the parameters for cyclical Sin/Cos operation on encoder
channel Ch 1 with one-time reading of the absolute encoder position via the
absolute value interface, i.e. without a zero pulse:
ID
Index Name
Unit Description
505
0
ENC_CH1_Sel = 1
Encoder selection set to SINCOS(1)
510
0
ENC_CH1_Num
Encoder gearing: Numerator
511
0
ENC_CH1_Denom
Encoder gearing: Denominator
540
0
ENC_CH1_Abs
Absolute value interface selection (one-time
reading)
542
0
ENC_CH1_lines
Number of Lines (Sin/Cos / TTL encoders)
543
0
ENC_CH1_MultiT
Number of MultiTurn bits (absolute encoder)
544
0
ENC_CH1_SingleT
Number of SingleTurn bits (absolute encoder)
545
0
ENC_CH1_Code
Code selection (SSI encoder) (binary, Gray)
546
0
ENC_CH1_Mode
Mode selection (SSI encoder)
547
0
ENC_CH1_MTBase
Definition of point of discontinuity in multi-turn
range
548
0
ENC_CH1_MTEnable
Enable MultiTurn use (negative logic, 1=MToff)
Table 6.9: Parameters for Channel 1 (X7) - Sin/Cos encoder
