iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 22/59
Calibration Using
Comparated Sine/Cosine Signals
Parameter
Output Signals
Op. Mode TRACMODE CALMODE BYP* Pins PSOUT, NSOUT, PCOUT, NCOUT Pin T0
Pin T1
Pin DIR
Signal calibration modes with comparated sine/cosine signals
DIGO_M
DIGA_M
DIGP_M
DIGO_S
DIGA_S
DIGP_S
DIGO_N
DIGA_N
DIGP_N
1
1
1
2
2
2
3
3
3
1
2
3
1
2
3
1
2
3
Calib. signals of master chan.
Calib. signals of master chan.
Calib. signals of master chan.
Calib. signals of segment chan.
Calib. signals of segment chan.
Calib. signals of segment chan.
Calib. signals of nonius chan.
Calib. signals of nonius chan.
Calib. signals of nonius chan.
DIGOFFCOS DIGOFFSIN
-
-
-
-
-
-
-
-
-
0
0
DIGAMP
DIGPHASE
DIGOFFCOS DIGOFFSIN
0
0
DIGAMP
DIGPHASE
DIGOFFCOS DIGOFFSIN
0
0
DIGAMP
DIGPHASE
Table 10: Operating modes for digital signal calibration
Calibration Of Signal Offsets Calibration Of Signal Amplitudes And Phase
Fig. 3: The duty ratio is set accurately to 50 % using Fig. 5: To calibrate the duty cycle to exactly 50 % the
parameter OFS_x. This measurement requires a high fine gain parameters GFC_x und GFS_x can balance
resolution, for instance of 0.06 %, for calibrating the off- the signal amplitudes. If a signal amplitude difference
set to 0.2 % with reference to the signal amplitude. The of 0.67 % remains after calibration, the interpolation
resulting interpolation error of 3 LSB (referred to a res- error enlarges to approx. 4.5 LSB at 13 bit resolution.
olution of 13 bits) corresponds to an angle error of 0.11
degree (360 degree means one signal period).
Fig. 6: Duty cycle calibration to exactly 50 % is carried
out using parameter PH_x. A remaining phase error of
Fig. 4: The duty ratio is set accurately to 50 % using 0.7 degree reduces the interpolation accuracy to 10 bit
parameter OFC_x.
(equal to 8 LSB error at 13 bit resolution, respectively).
degree
0.2
degree
0.2
0.1
0
0.1
0
-0.1
-0.2
-0.1
-0.2
0
90
180
270
360
0
90
180
270
360
Figure 3: Mode DIGO_x: DIGOFFSIN at Pin T1.
Figure 5: Mode DIGA_x: DIGAMP at Pin T1.
degree
0.4
degree
0.2
0.1
0
0.2
0
-0.1
-0.2
-0.2
-0.4
0
90
180
270
360
0
90
180
270
360
Figure 4: Mode DIGO_x: DIGOFFCOS at Pin T0.
Figure 6: Mode DIGP_x: DIGPHASE at Pin T1.
ICHAUS [ IC-HAUS GMBH ]
