IC-MU_13 Datasheet, PDF (37/59 Pages) IC-Haus GmbH – OFF-AXIS NONIUS ENCODER WITH INTEGRATED HALL SENSORS

iC-MU OFF-AXIS NONIUS ENCODER
WITH INTEGRATED HALL SENSORS
preliminary
Rev B1, Page 37/59
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
NCHK_NON
Addr. 0x0D; bit 5
Code
Description
0
automatic period verification
1
no automatic period verification
Table 54: Automatic nonius period verification
The nonius data and incremental interface can be au-
tomatically reset with ACRM_RES if the master ampli-
tude 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 Ta-
ble 91). 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 incremen-
tal section is restarted.
ACRM_RES
Addr. 0x0D; bit 4
Code
Description
0
no automatic reset
1
automatic reset active
Figure 30: Nonius track offset calibration
Table 55: Automatic Reset triggered by AM_MIN
normal operation
Following the first nonius synchronization the num-
ber of excessed periods is counted and output. Us-
ing 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 explicitly requests nonius verification. If
an error is found during verification of the nonius, bit
NON_CTR is set in status register STATUS1.
ACRM_RES? ^no
yes
AM_MIN
no
error set?
yes
reset incr. part
no
incr. part
in reset state?
yes
wait
20 ms
Figure 31 describes the principle of nonius synchro-
nization with verification, with ϕ representing the re-
spective digitized angle of the relevant track.
initial nonius calculation
ϕm - ϕn
SYNC BITS
ϕm
CORRECTION
MPC
12 Bit
ϕm
CNT_PERIOD
+
ϕabsolut
MSB
INTERNAL
LSB _{W ORD}
nonius reset
multiturn reset
yes _{startup multiturn no}
ok?
restart incr. part
Figure 32: Automatic reset ACRM_RES
Figure 31: Principle of nonius synchronization