NOTE
Please note the limitations that apply when running EnDat and
SSI encoders (
see Section
"Limiting for EnDat and SSI" on
When using linear encoders, P 554[0] - ENC_CH1_DigitalResolution is used
instead of P 543[0] - ENC_CH1_MultiT and P 544[0] - ENC_CH1_SingleT (which
are used for rotary encoders). The values will be read from the EnDat encoder and
written to the aforementioned parameters.
P 543[0] - ENC_CH1_MultiT
The number "n" of multi-turn bits defines the measuring range in 2
n
increments per encoder shaft revolution; maximum travel until overflow;
maximum travel within which the absolute value initialization can be
unambiguous. In the case of single-turn encoders, MultiT = 0.
P 544[0] - ENC_CH1_SingleT
The number "n" of single-turn bits corresponds to the encoder’s digital
resolution in 2
n
increments per encoder shaft revolution.
P 554[0] - ENC_CH1_DigitalResolution
This is the length of an increment, in nanometres, of the encoder’s digitally
transmitted position value. This value is read from the EnDat linear head.
In the case of linear encoders, the number n of transmitted position bits from the
encoder will be found in SingleT only! 2
n
* DigitalResolution yields the maximum
travel in nanometres (for the encoder head).
P 640 - ENC_ENDAT is intended for additional information, but is normally
not
needed. This parameter does not have a Ch1 or Ch3 prefix for the encoder channel
in the name, as it applies to both encoder channels. Although usually not needed,
the parameter is helpful or required in the following cases:
1.
Special EnDat encoder with diagnostics for evaluation
In this case, the valuation numbers from the encoder are read cyclically via
additional information. Only the valuation numbers that the encoder supports
MOOG
ID
No.:
CB40859-001
Date:
02/2018
MSD Servo Drive - Device Help
59
6 Encoder
will be read. During the initialization process, the system will read the
encoder to determine which valuation numbers it supports. When
P 640[0] -
ENDAT_Select
= 1, the function will be enabled in the drive and the internal
diagnostics in the EnDaT encoder will be enabled as well. The EnDat
encoder will keep this setting even after being powered off. To explicitly
disable the internal diagnostics in the EnDat encoder, set
P 640[0] -
ENDAT_Select
to 2.
2.
Evaluation of internal warnings
In this scenario, certain internal warnings from the encoder will be read from
the encoder via additional information. Only the warnings supported both by
the encoder and the servo drive software will be read. During the
initialization process, the system will read the encoder to determine which
warnings it supports. When
P 640[0] - ENDAT_Select
= 3, the function will
be enabled in the drive.
ID
Index Name
Unit
Description
505
0
ENC_CH1_Sel = 4
= ENDAT(4)
543
0
ENC_CH1_MultiT
Number of MultiTurn bits (absolute encoder)
544
0
ENC_CH1_SingleT
Number of SingleTurn bits (absolute encoder)
547
0
ENC_CH1_MTBase
Definition of point of discontinuity in multi-turn
range
548
0
ENC_CH1_MTEnable
1: Use multi-turn encoder as single-turn
encoder
616
0
ENC_CH1_CycleCount
Position encoder sampling cycle (n x 125
µsec)
598
0
ENC_CH1_Position
inc
Position encoder channel 1
554
0
ENC_CH1_
DigitalResolution
nm
Length of one increment (linear absolute
encoder)
640
ENC_ENDAT
EnDat additional (additional information)
640
0
ENDAT_Select
0=off
EnDat function selection, 1/2=diagnosis
on/off, 3=warnings, FF=lock
640
1
ENDAT_DiagCount
u16
count new diagnosis block header
640
2
ENDAT_BWZ_1
lowbyte
vn1: incremental track
640
3
ENDAT_BWZ_3
lowbyte
vn3: absolute track
640
4
ENDAT_BWZ_4
lowbyte
vn4: position value formation
640
5
ENDAT_Status
EnDat additional status output
640
6
ENDAT_Z1_Sel
EnDat additional information 1 type selection
Table 6.7: Channel 1 encoder configuration (X7) - EnDat parameters
