Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Setting Up Turbo PMAC-Based Commutation and/or Current Loop
121
Using the Test Results
To execute a power-on phasing using the hall-effect sensors, you can use new modes of the Ixx81 power-
on phase position parameter, or write a simple PLC program that executes once on power-up/reset.
To execute a power-on phasing using the hall-effect sensors, you can use new modes of the Ixx81 power-
on phase position parameter, or write a simple PLC program that executes once on power-up/reset.
Setting bit 23 of Ixx81 to 1 specifies a hall-effect power-on phase reference. In this case, the address
portion of Ixx81 specifies a Turbo PMAC X-address, usually that of the flag register used for the motor,
the same address as in Ixx25.
portion of Ixx81 specifies a Turbo PMAC X-address, usually that of the flag register used for the motor,
the same address as in Ixx25.
Turbo PMAC expects to find the hall-effect inputs at bits 20, 21, and 22 of the specified register. In a flag
register, these bits match the CHWn, CHVn, and CHUn inputs, respectively. Hall-effect inputs are
traditionally labeled U, V, and W.
register, these bits match the CHWn, CHVn, and CHUn inputs, respectively. Hall-effect inputs are
traditionally labeled U, V, and W.
Each hall-effect signal must have a duty cycle of 50% (180
o
e). PMAC can use hall-effect commutation
sensors separated by 120
o
e. There is no industry standard with hall-effect sensors as to direction sense or
zero reference, so this must be handled with software settings of Ixx81.
Bit 22 controls the direction sense of the hall-effect sensors as shown in the following diagrams, where a
value of 0 for bit 22 is standard and a value of 1 is reversed:
value of 0 for bit 22 is standard and a value of 1 is reversed:
U
V
W
-30
30
90
150
-150
-90
1
0
1
0
1
0
30
-30
-90
-150
90
150
Standard:
Reversed:
Reversed:
UVW Value: 1
3
2
6
4
5
This diagram shows the hall-effect waveforms with zero offset, defined such that the V-signal transition
when the U-signal is low (defined as the zero point in the hall-effect cycle) represents the zero point in
PMAC’s commutation cycle.
when the U-signal is low (defined as the zero point in the hall-effect cycle) represents the zero point in
PMAC’s commutation cycle.
If the hall-effect sensors do not have this orientation, bits 16 to 21 of Ixx81 can be used to specify the
offset between PMAC’s zero point and the hall-effect zero point. These bits can take a value of 0 to 63
with units of 1/64 of a commutation cycle (5.625
offset between PMAC’s zero point and the hall-effect zero point. These bits can take a value of 0 to 63
with units of 1/64 of a commutation cycle (5.625
o
e).
The offset can be computed using the mapping test shown above. In our example, the hall effect zero
(HEZ) point was found to be between 30
(HEZ) point was found to be between 30
o
e and 90
o
e, so we will call 60
o
e. The offset value can be
computed as
64
*
o
o
360
360
%
HEZ
Offset
=
The offset computed here should be rounded to the nearest integer.
In our example, this comes to:
In our example, this comes to:
hex
0
11
667
.
10
64
o
360
o
60
64
o
o
360
360
%
o
60
Offset
Β
=
≈
=
∗
=
∗
=
The test showed that the hall-effect sensors were in the standard direction, not reversed, so bit 22 is left at
zero. With bit 23 (a value of 8 in the first hex digit) set to 1 to specify hall effect sensing, the first two
hex digits of Ixx81 become $B5. If Flag register 1 at address $C000 were used for the hall-effect inputs,
Ixx81 would be set to $B5C000.
zero. With bit 23 (a value of 8 in the first hex digit) set to 1 to specify hall effect sensing, the first two
hex digits of Ixx81 become $B5. If Flag register 1 at address $C000 were used for the hall-effect inputs,
Ixx81 would be set to $B5C000.