IC-MN_16 Datasheet, PDF (48/62 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
Rev F2, Page 48/62
DL_MT
Code
0x00
...
0x0C
0x0D
0x0E
0x0F
Notes
Addr. 0x3E; bit 7:5
Multiturn bit count*
8
...
20
24
1
4
*) Does not include synchronization bits of the
external MT sensor.
Table 84: MT data length (and counter depth)
SBL_MT
Code
00
01
10
11
Addr. 0x41; bit 1:0
MT synchronization bit Synchronization range
length
(ST resolution)
1 bit
± 90°
2 bit
± 90°
3 bit
± 135°
4 bit
± 157.5°
Table 85: MT synchronization bit length
quest for the external multiturn data are repeated (with
a break of 128 µs) up to three times (see Figure 21). If
the error persists after a fourth attempted readin, the
device goes into normal operating mode. Conversion
requests for the singleturn position data are possible,
but MT_ERR remains permanently set.
The error handling in normal operating mode when
the multiturn data verification is activated is shown in
Figure 22. If there is an error in communication no
further readouts are attempted and MT_ERR remains
permanently set.
startup
sequence with
16 ms timeout
read external
multiturn
mt-error-counter ++
LNT_MT
Code
0
1
Addr. 0x41; bit 2
Function (single sync. bit, SBL_MT = 0x00)
Trailing
Leading
Table 86: Leading/trailing gear box assembly
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 position data)
is signaled via the error bit (MT_CTR is set in the status
register, see page 43).
CHK_MT
Code
0
1
Addr. 0x40; bit 6
Function
Verification disabled
Cyclic verification each 8 ms
serial-communication error?
yes
no
yes
mt_error-counter < 4
no
set MT_ERR
sync to flashcounter
proceed with
startup-sequence
proceed with
startup-sequence
no further multiturn-readouts
started
Figure 21: Error handling during start up phase
normal operation:
ready for
sensordata-requests
CHK_MT?
yes
Table 87: Period counter verification
start timer
GRAY_MT
Code
0
1
Addr. 0x41; bit 3
Data format
Binary coded
Gray coded
Table 88: MT Interface data format
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 external
MT sensor not responding), the first conversion and re-
timer == 8 ms?
yes
read external
multiturn
sync to flashcounter
and compare to counted
no
multiturn-value
serial
communication
error?
no
compare-error?
yes
yes
set MT_CTR
set MT_ERR
Figure 22: Error handling during normal operation
with cyclic period counter verification