iC-ML
HALL Position Sensor / Encoder
Rev A3, Page 14/17
Incremental ABZ modes
Mode
NEN CFG1 CFG2 CFG3
Port A
Port B
Port C
Port D Res. Comments
Incr. ABZ
ABZ 8-1 low
ABZ 8-0 low open low open
ABZ 7-1 low low open open
ABZ 7-0 low open open open
ABZ 6-1 low low high open
ABZ 6-0 low open high open
ABZ 8-1 low low low high
ABZ 8-0 low open low high
ABZ 7-1 low low open high
ABZ 7-0 low open open high
ABZ 6-1 low low high high
ABZ 6-0 low open high high
low
low open
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
B
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
NERR
NERR
NERR
NERR
NERR
NERR
NERR
NERR
NERR
NERR
NERR
NERR
8
8
7
7
6
6
8
8
7
7
6
6
AB=1
AB=0
AB=1
AB=0
AB=1
AB=0
AB=1, PRM
AB=0, PRM
AB=1, PRM
AB=0, PRM
AB=1, PRM
AB=0, PRM
iC-ML has an 8-bit sine/digital converter which can sensor via NEN at low the sensor looks for its oper-
convert the sine/cosine sensor signals into a digitized ating point. If 70 % of the set amplitude is achieved the
angle. This angle is made available at the ports as an error signal is reset. An error status during this phase
incremental value. Signal Z is always high when the is also signaled when signals A and B are high and Z
angle is 0°; otherwise the signal is low. In all incremen- low. In an error-free state Z is always high at zero po-
tal modes of operation error signal NERR is available sition. iC-ML continues to search for its operating point
so that the plausibility of the counter value can be veri- by outputting the position of the external magnetic field
fied. At an amplitude which is less than 50 % of the set at maximum count frequency via the incremental in-
amplitude the error signal switches to low; at an ampli- terface. Once the actual position has been obtained
tude greater than 70 % the error signal is reset, i.e. set the device follows a changed input signal in real time.
to high.
The edge frequency is thus 256 times the frequency of
periodical movement of the magnetic tape at a set res-
Three different quantities regarding the number of olution of 8 bits. If a (rising) edge reaches B before a
edges per rotation of the magnet can be selected. (rising) edge A, this means that the counter value has
These are a resolution of 6 bits (64 edges per rota- risen. If the edge reaches A before B, however, this
tion), 7 bits (128 edges) or 8 bits (256 edges). The indicates that the absolute value is lower.
conversion process is count-safe, i. e. the output of all
edges up to the current angle position is guaranteed as
long as the input frequency is less than the maximum
possible rotation.
NEN
All incremental resolutions also have a reduced power
consumption mode(PRM). In this mode the Hall sen-
sor is supplied with current intermittently, reducing the
NERR
power consumption. Here it must be noted that the
maximum input frequency drops by a factor of 2.
A
A distinction can be made between the various modes
of operation by studying the level of the AB signals on
B
the Z pulse. In mode AB = 1 signals A and B are both
high, as is Z at an angle of 0°. In mode AB = 0, how-
Z
ever, both signals A and B are low when the Z signal
is high.
Time [us]
Firstly, the behavior of the sensor on switching on the
Figure 17: Incremental signals after switching on
device is described when the magnetic tape moves in
the device, counting up
the +x-direction (Figure 17). After switching on the
ICHAUS [ IC-HAUS GMBH ]
