Delta Tau Acc-51E, Руководство пользователя

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Accessory 51E
18 Turbo UMAC and the UMAC Interpolator
TURBO UMAC AND THE UMAC INTERPOLATOR
I-Variables for Turbo UMAC Processor
Refer to the Turbo PMAC Software Reference Manual for a more detailed description of the use of the I-
Variables as described below.
To process the interpolator’s data properly, several I-Variables must be set:
Encoder Decode Control I-Variables (I7mn0)
I7mn0 is used to establish encoder decoding. ‘m’ is the servo IC number as established by the Acc-51E
mapping table (in the previous section); ‘n’ is the channel number, which is the same as the encoder
number (1-4) on the Acc-51E board. The encoder decode control I-variable is set for each channel to
which an interpolator is connected.
For Servo IC’s that use the alternate addressing labeled Servo ICs 2* through 9*. Servo IC m* is
representing channels 6 to 9. For example: the I-variable for the first channel on Servo IC 2* is I7260 to
I7269.
Refer to the Acc-51E mapping table described in the Dipswitch and Mapping section of this manual for
the servo IC number ‘m’ value.
A value of 7 is used as default for CCW x4 Quadrature decode. Changing the decode direction requires
the operator to save the Turbo PMAC’s parameters and perform a
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or cycle power.
Note:
Reset the PMAC if the encoder direction has been changed to prevent encoder instability.
Motor xx Counts per N Commutation Cycles (Ixx71)
For a Turbo PMAC-commutated motor, this parameter defines the size of a commutation cycle in
conjunction with Ixx70 (hardware counts/cycle = Ixx71/Ixx70. For example, if a sinusoidal encoder with
2000 lines is used, Ix71 will be set to 8000 hardware counts.
Motor xx Number of Commutation Cycles (N) (Ixx70)
For a PMAC-commutated motor (Ixx01=1), Ixx70 is used in combination with Ixx71 to define the size of
the commutation cycle, as Ixx71/Ixx70 counts. For example, a 4-pole rotary brushless motor has a
sinusoidal encoder with 2000 lines. There are 8000 hardware counts per revolution, and two
commutation cycles per revolution of the 4-pole motor. Therefore, Ix70 will be set to 2, and Ix71 will be
set to 8000. Ix83 will contain the address of the hardware counter’s phase capture register.
Commutation Position I-Variables (Ixx83)
The Acc-51E contains a quadrature-based encoder register that may be used for commutation position.
The PMAC2 does not use the Acc-51’s full interpolation to track a motor’s position.
The number of commutation counts per pole revolution or linear scale distance is related to the pitch of
the encoder’s sinusoidal output multiplied by 4. Therefore, commutation appears to the PMAC2 as if it
were a quadrature-based encoder.