IC-MU_17 Datasheet, PDF (40/66 Pages) IC-Haus GmbH – MAGNETIC OFF-AXIS POSITION ENCODER - POLE WIDTH 1.28MM

iC-MU MAGNETIC OFF-AXIS
POSITION ENCODER - POLE WIDTH 1.28MM
Rev D1, Page 40/66
an error within 22.5° (in the Figure between 67.5° and
90°) can not be corrected. For SPO_0 the range of a
possible slope change is exemplary shown.
0°
22.5° ^{45° 67.5° 90° 112.5° 145° 167.5°180° 202.5°225° 247.5°270° 292.5°315° 337.5°3r6e0°lative} to
M-N
slope used
in range
+ 1 period
- 1 period
tolerable
offset
error
SPO_BASE
SPO_0
SPO_1
error curve
resulting curve
spo_x curve
spo_x correction
range
Figure 33: Nonius track offset calibration
NCHK_NON
Addr. 0x0D; bit 5
Code
Description
0
automatic period verification
1
no automatic period verification
Notes:
For max. duration of the internal cyclic checks see
elec. char. no. 408
Table 58: Automatic nonius period verification
The nonius data and incremental interface can be auto-
matically reset with ACRM_RES if the master amplitude
is too low. The incremental section is reset as soon
as the amplitude control unit indicates that the master
amplitude is too low (AM_MIN occurs, see Table 96).
The ABZ-interface shows position 0 as default. When
the master amplitude is again in its set range, a new
nonius calculation is carried out and the incremental
section is restarted.
ACRM_RES
Addr. 0x0D; bit 4
Code
Description
0
no automatic reset
1
automatic reset active
Table 59: Automatic Reset triggered by AM_MIN
Following the first nonius synchronization the number
of excessed periods is counted and output. Using
NCHK_NON the system can be configured to check the
internal period counter against the period given by the
code disc at regular intervals. Command NON_VER ex-
plicitly requests nonius verification. If an error is found
during verification of the nonius, bit NON_CTR is set in
status register STATUS1.
Figure 34 describes the principle of nonius synchroniza-
tion with verification, with φ representing the respective
digitized angle of the relevant track.
normal operation
ACRM_RES? ^no
yes
AM_MIN
no
error set?
yes
reset incr. part
no
incr. part
in reset state?
yes
wait
20 ms
nonius reset
initial nonius calculation
jm - jn
SYNC BITS
jm
CORRECTION
MPC
12 Bit
jm
CNT_PERIOD
+
jabsolut
MSB
INTERNAL
LSB _{W ORD}
Figure 34: Principle of nonius synchronization
multiturn reset
yes _{startup multiturn no}
ok?
restart incr. part
Figure 35: Automatic reset ACRM_RES