IC-MHM Datasheet, PDF (45/63 Pages) IC-Haus GmbH – 14-BIT ABSOLUTE ANGLE HALL ENCODER

iC-MHM
14-BIT ABSOLUTE ANGLE HALL ENCODER
Rev D1, Page 45/63
are transmitted MSB first in the order shown in
Table 86.
Extended SSI Protocol Frame
Bit Length Description
0 - 32
Multiturn Position (Turns Count - OFFS_MT)
12 or 16 Singleturn Position (Magnet Angle - OFFS_ST)
1
Error Bit nE (Active Low)
1
Warning Bit nW (Active Low)
0 or 6
Optional Sign-of-Life Counter
(SSI Cycle Count)
Table 86: Extended SSI Protocol Frame
The active-low warning bit, nW, is activated if magnet
rotation speed is excessive. Refer to INTERPOLATOR
on page 21 for more information on maximum rotation
speeds.
In safety applications, a sign-of-life counter (life counter)
value can be transmitted after the warning bit in the SSI
frame.
ENLC
Value
0
1
Address 0x0A; bit 6
Description
Sign-of-Life Counter Disabled
6-Bit Sign-of-Life Counter Value
Refer to POSITION OFFSET AND PRESET (Zero Po-
sition) on page 55 for more information on the position
offset parameters OFFS_MT and OFFS_ST.
Table 87: Sign-of-Life Counter Enable
If the sign-of-life counter is enabled (ENLC = 1), a 6-bit
count value (0 - 63) is transmitted last in the SSI frame.
The singleturn bit length depends on the interpolator
resolution as set by parameter RESO_ST, but is always
fixed at 12 or 16 bits. If the singleturn resolution (in bits)
is less than one of these values, the singleturn position
value is left-justified in the singleturn position field and
the unused LSBs are set to zero.
For example, if RESO_ST = 6, the singleturn position
(angle) is a 10-bit value in a 12-bit field. In this case,
bits 9:0 contain the singleturn position while bits 11:10
are zero. Refer to INTERPOLATOR on page 21 for
more information on RESO_ST.
The active-low error bit, nE, is activated when any of the
error bits in the error status register is active. Refer to
STATUS REGISTERS on page 30 for more information.
Its reset value of zero is never output as it is bypassed
during normal operation.
LC
Code
0x00
0x01
...
0x3F
Value
Initial value after power-on, reset and preset
Value on first request for new position data
and follow-up value on the maximum
...
Max. value
Table 88: Sign-of-life counter
The count value is incremented after each new BiSS
cycle. If the sign-of-life counter is disabled (ENLC = 0),
no additional bits are transmitted and the CRC code
immediately follows the nWARN bit in the SCD.