IC-MN_16 Datasheet, PDF (27/62 Pages) IC-Haus GmbH – 25-BIT NONIUS ENCODER WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION

iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
ANALOG PARAMETERS
Rev F2, Page 27/62
Signal Level Controller
By tracking the sensor’s power supply via the controlled
current sources (outputs ACOM, ACOS and ACON)
iC-MN can keep the sine/cosine track signals for the
ensuing sine-to-digital converter constant regardless of
temperature and aging effects.
ACOR_M(6:5)
Addr. 0x0C; bit 6:5
Code
Current range Imax(ACOM)
00
5 mA
01
10 mA
10
25 mA
11
50 mA
When adjusting the signal conditioning a constant cur-
rent source is used in place of the controlled current
source, the set current of which can be adjusted using
ACOR_M(6:0) or ACOR_x(5:0) (x = S, N). This cur-
rent must be so low as to leave enough reserve for
temperature and aging effects and ensure that no un-
necessary power dissipation is generated. However,
the source current may not be too low so as to permit
a better signal contrast and improved signal to noise
ratio. Using this current the signal calibration can then
be performed so that the sine/cosine signals at the sine-
to-digital converter have a (differential) value of 6 Vpp
in their calibrated state. Once calibration has proved
successful the signal level controller can be activated.
There are three integrated signal level control units in
iC-MN, all of which are powered by VACO. It is thus
possible to regulate each track individually or, in optical
systems with an LED, for example, all three tracks us-
ing the master signal level controller. If the control unit’s
working range is exceeded, an error is generated.
Table 29: Current source range, ACOM output
ACOC_M(4:0)
Addr. 0x0C; bit 4:0
Code
Setpoint
0x00
0x01
...
3.125% * Imax(ACOM)
6.25% * Imax(ACOM)
...
0x1E
0x1F
96.875% * Imax(ACOM)
100% * Imax(ACOM)
Table 30: Current source setpoint, ACOM output
ACOT_S(7:6)
Addr. 0x1D; bit 0
Addr. 0x1C; bit 7
ACOT_N(7:6)
Addr. 0x2D; bit 0
Addr. 0x2C; bit 7
Code
Operating mode
00
Square control active
01
Sum control active
10
Constant current source mode
11
Not permitted
Table 31: Controller op. mode, ACOS/ACON outputs
ACOT_M(8:7)
Addr. 0x0D; bit 0
Addr. 0x0C; bit 7
Code
Operating mode
00
Square control active*
01
Sum control active
10
Constant current source mode
11
Not permitted
*) Square control of V()scq =
(V(PSOUT − V(NSOUT))² + (V(PCOUT − V(NCOUT))²
Table 28: Controller op. mode, ACOM output
Notice: Excessive input signals or internal signal clipping
can interfere control operation, so that the preset operating
point may not be reached (upon power up) or maintained
(upon disturbances). Use Control Error ACM_max and Sig-
nal Error AM_min for monitoring and warning messaging;
configure CFGEW accordingly.
ACOR_S(5)
Addr. 0x1C; bit 5
ACOR_N(5)
Addr. 0x2C; bit 5
Code
Current range Imax(ACOS), Imax(ACON)
0
5 mA
1
10 mA
Table 32: Current source range, ACOS/ACON outputs
ACOC_S(4:0)
Addr. 0x1C; bit 4:0
ACOC_N(4:0)
Addr. 0x2C; bit 4:0
Code
Setpoint
0x00
3.125% * Imax(ACOS, ACON)
0x01
6.25% * Imax(ACOS, ACON)
...
...
0x1E
96.875% * Imax(ACOS, ACON)
0x1F
100% * Imax(ACOS, ACON)
Table 33: Current source setpoint, ACOS/ACON output