iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 49/59
MT INTERFACE with EXTENDED FUNCTIONS
SWC_MT
Addr. 0x41; bit 6
The serial multiturn interface can be operated in the
BiSS C protocol which enables multiturn sensor error
messages to be evaluated (via the error and warning
bits, each of which are low active) and communica-
tion to be monitored (evaluation of the CRC bits, see
Figure 25).
Code
CRC polynomial (HEX)
0
1
0x43
0x25
Table 91: MT Interface CRC polynomial
The error behavior of the multiturn interface has al-
ready been described in Figures 20 and 21; only a set
error bit (low) or a CRC error are now also classified
as a communication error.
NCRC_MT
Addr. 0x41; bit 4
Function
Code
0*
CRC verification active
Disabled
1
Note
*) Only permitted with MODE_MT = 01.
MODE_MT
Code
00
Addr. 0x40; bit 4:3
Function
Table 92: MT Interface CRC verification
Internal multiturn period counting
BiSS C protocol
01
Notes
If MODE_MT is altered during operation, command
SOFT_RES must be issued (see page 42).
Table 90: MT Interface operation mode
M TM A
M TS L I
A
C
K
S
T
A
R
T
M
S
B
L
S
B
N
E
R
R
N
W
R
N
M
S
B
L
S
B
MT_ E R R +
MT_ WR N
D
L
_
M
T
+
S
B
L
_
M
T
C
R
C
(
N
C
R
C
_
M
T
=
0
)
t
o
u
t
Figure 25: Example of the MT interface line signals with BiSS C protocol
Direct Communication To Multiturn Sensor
ing the singleturn data. With GET_MT enabled, the
Making use of the BiSS Interface bus capabilities, iC- external multiturn can then be addressed via BiSS ID
MN can connect the external multiturn sensor to the 0 and the singleturn via BiSS ID 1. This temporal
BiSS master controller when GET_MT is enabled. To chain operation eases device parameterization during
this end pin MA receiving the BiSS master’s clock sig- encoder manufacturing.
nal is fed through to pin MTMA and the MTSLI pin is
activated in place of the SLI pin. Upon enabling this
GET_MT
Addr. 0x41; bit 5
Function
mode the singlecycle timeout must have elapsed and
an additional init command carried out by the BiSS
master, before it can run the first register communi-
cation.
Code
0
1
Disabled
MT sensor communication enabled
Table 93: Direct BiSS communication enable for MT
sensor via I/O Interface
Example: external multiturn sensor built with iC-MN is
connected to the MT interface of a first iC-MN, prepar-
ICHAUS [ IC-HAUS GMBH ]
