H u d s o n M a n u a l / R e v . 1 . 2 1
1 7
T
EKNIC
,
I
NC
.
P H O N E ( 5 8 5 ) 7 8 4 - 7 4 5 4
Commutation (Hall) Signaling
The optical commutation sensors are 5V TTL, totem pole driven outputs with
10mA maximum current.
Commutation Signal and Motor Phase Relaionship
The diagram below illustrates the relationship between commutation (Hall)
outputs and motor phases for properly wired Hudson motors. Refer to this
diagram when wiring third-party servo drives to Hudson motors. When using
the diagram below, bear in mind the following:
•
The waveforms below apply to sine wave drives that can process
120° commutation sensor (Hall) signals and use encoder-based
commutation.
Note: Six-step drives would produce a different back
EMF signature than shown below.
•
The drive must be wired to count
up
as the motor shaft is turned
CCW (looking into the shaft).
•
The commutation sequence shown in gray below
is read from right
to left.
When spinning the shaft CCW, a properly wired motor should
report commutation codes in the following sequence: 100, 101, 001,
011, 010, 110.
0°
30°
60°
90°
120° 150° 180° 210° 240° 270° 300° 330° 360°
0°
30°
60°
90°
120° 150° 180° 210° 240° 270° 300° 330° 360°
PHASE T
PHASE R
PHASE S
Back EMF
waveforms
Commutation sensor
(Hall effect) signals
COMM. T-R
COMM. S-T
COMM. R-S
110
010
011
001
101
100
(6)
(2)
(3)
(1)
(5)
(4)
(referenced to phase R)
(referenced to phase S)
(referenced to phase T)
(Decimal)
Binary
Commutation
Sensor Codes
(
read rIght to left
for CCW rotation
)
Note: Motor phase zero-crossings must line up
with commutation sensor transitions as shown
motor phase
zero crossing
commutation
sensor transition
The above diagram shows the back-EMF waveforms you’d see if the motor
shaft was spun counterclockwise (looking into the shaft) with an oscilloscope
probe attached to the phase of interest and the ground clip attached to the
reference phase. The lower part of the diagram shows how the commutation
signals would appear on an oscilloscope when probed signal to ground.