iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 47/59
SBL_MT
Addr. 0x41; bit 1:0
further readouts are attempted and MT_ERR remains
permanently set.
Code
MT synchronization bit
length
Synchronization range
(ST resolution)
00
01
10
11
1 bit
2 bit
3 bit
4 bit
± 90°
startup
sequence with
16 ms timeout
± 90°
± 135°
± 157.5°
Table 85: MT synchronization bit length
mt-error-counter ++
read external
multiturn
LNT_MT
Addr. 0x41; bit 2
yes
mt_error-counter < 4
no
Code
Function (single sync. bit, SBL_MT = 0x00)
serial-communication error?
yes
0
1
Trailing
Leading
no
set MT_ERR
Table 86: Leading/trailing gear box assembly
sync to flashcounter
proceed with
startup-sequence
proceed with
Via CHK_MT the device can be configured so that the
counted multiturn period is verified every 8 ms. An
error in the multiturn check (the comparison of the
counted multiturn period and the external multiturn po-
sition data) is signaled via the error bit (MT_CTR is set
in the status register, see page 43).
startup-sequence
no further multiturn-readouts
started
Figure 20: Error handling during start up phase
normal operation:
ready for
sensordata-requests
CHK_MT
Addr. 0x40; bit 6
Function
Code
CHK_MT?
0
1
Verification disabled
Cyclic verification each 8 ms
yes
start timer
Table 87: Period counter verification
GRAY_MT
Addr. 0x41; bit 3
Data format
read external
multiturn
timer == 8 ms?
yes
Code
0
1
Binary coded
Gray coded
sync to flashcounter
and compare to counted
multiturn-value
serial
communication
error?
no
Table 88: MT Interface data format
yes
no
compare-error?
yes
Error Handling
If a communication error appears when reading in ex-
ternal multiturn data during the startup phase (such
as pin MTSLI reading a permanent logic 0 or the exter-
nal MT sensor not responding), the first conversion and
request for the external multiturn data are repeated up
to three times (see Figure 20). If the error persists after
a fourth attempted readin, the device goes into normal
operating mode. Conversion requests for the single-
turn position data are possible, but MT_ERR remains
permanently set.
set MT_CTR
set MT_ERR
Figure 21: Error handling during normal operation
with cyclic period counter verification
M TMA
M TSL I
M
S
B
L
S
B
D
L
_
M
T
+
S
B
L
_
M
T
t
o
u
t
The error handling in normal operating mode when
the multiturn data verification is activated is shown in
Figure 21. If there is an error in communication no
Figure 22: Line signals of the serial MT interface
MODE_MT = 0x10 (SSI)
ICHAUS [ IC-HAUS GMBH ]
