Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
142
Motor Compensation Tables and Constants
Examples:
I8008=$C78200
; No extension of Servo IC 2 Channel 1
I8009=$C78208
; No extension of Servo IC 2 Channel 2 (PMAC2 IC)
Analog Sine/Cosine Encoders
Turbo PMAC supports two methods of conversion for interpolating analog sine/cosine encoders: one low-
resolution (128 or 256 states per line) and one high-resolution (4096 states per line). The source
addresses are always the base addresses of encoder channels in the Servo ICs.
resolution (128 or 256 states per line) and one high-resolution (4096 states per line). The source
addresses are always the base addresses of encoder channels in the Servo ICs.
Low-Resolution Interpolation (Method digit $8)
This method reads five bits of externally calculated fractional count data presented in parallel to the Turbo
PMAC, and uses the quadrature counter for whole-count data. It is intended for use with the interpolator
circuitry on the Acc-8D Option 8 and the Acc-8A through normal PMAC servo channels. The mode-
switch bit is set to 0 if the data is read through a PMAC-style Servo IC; it is set to 1 if the data is read
through a PMAC2-style Servo IC. This is a one-line entry.
PMAC, and uses the quadrature counter for whole-count data. It is intended for use with the interpolator
circuitry on the Acc-8D Option 8 and the Acc-8A through normal PMAC servo channels. The mode-
switch bit is set to 0 if the data is read through a PMAC-style Servo IC; it is set to 1 if the data is read
through a PMAC2-style Servo IC. This is a one-line entry.
A full list of source addresses is given in the Software Reference Manual. Common source addresses are:
PMAC on-board channels 1 – 4: $78000, $78004, $78008, $7800C
PMAC2 on-board channels 1 – 4: $78000, $78008, $78010, $78018
PMAC2 on-board channels 1 – 4: $78000, $78008, $78010, $78018
Note that the encoder counter used must be set up for times 4 decode by the decode variable I7mn0 for
the encoder channel, and that only one of the two possible direction senses may be used. With Delta Tau
accessories and standard wiring, the I7mn0 variable must be set to 7. If this is wrong, the direction senses
of the fractional and whole-count data will not match.
Examples:
the encoder channel, and that only one of the two possible direction senses may be used. With Delta Tau
accessories and standard wiring, the I7mn0 variable must be set to 7. If this is wrong, the direction senses
of the fractional and whole-count data will not match.
Examples:
I8004=$878100
; Low-res interpolation of Servo IC 1 Channel 1 (PMAC1 IC)
I8005=$8F8018
; Low-res interpolation of Servo IC 0 Channel 4 (PMAC2 IC)
High-resolution Interpolation (Method digit $F, extended method digit on second line $0)
This method calculates 10 bits of fractional count data (1024 states) per quadrature count – 4096 states
per line – by reading A/D converters on an Acc-51 board for the sine and cosine signals and computing
the arctangent. The whole count data comes from the digital quadrature counter. The mode-switch bit is
set to 0 if the data is read through a PMAC-style Servo IC (Acc-51P); it is set to 1 if the data is read
through a PMAC2-style Servo IC (Acc-51E, 51C).
A full list of source addresses is given in the Software Reference Manual. Common source addresses are:
Acc-51P as Servo IC 2, channels 1 – 4: $78200, $78204, $78208, $7820C
Acc-51E as Servo IC 4, channels 1 – 4: $79200, $79208, $79210, $79218
The second line contains the address of the first of the two ADCs read, with a $0 in the first hex digit.
For the Acc-51P, the ADC address is two higher than the channel base address used in the first line; for
the Acc-51E and 51C, it is five higher.
Common source addresses for the ADCs are:
Acc-51P as Servo IC 2, channels 1 – 4: $78202, $78206, $7820A, $7820E
Acc-51E as Servo IC 4, channels 1 – 4: $79205, $7920D, $79215, $7921D
The third line is a 24-bit bias term that is subtracted from both 24-bit words containing the ADC values
(even though the ADCs only occupy the top 14 bits) before the arctangent calculations are done.
per line – by reading A/D converters on an Acc-51 board for the sine and cosine signals and computing
the arctangent. The whole count data comes from the digital quadrature counter. The mode-switch bit is
set to 0 if the data is read through a PMAC-style Servo IC (Acc-51P); it is set to 1 if the data is read
through a PMAC2-style Servo IC (Acc-51E, 51C).
A full list of source addresses is given in the Software Reference Manual. Common source addresses are:
Acc-51P as Servo IC 2, channels 1 – 4: $78200, $78204, $78208, $7820C
Acc-51E as Servo IC 4, channels 1 – 4: $79200, $79208, $79210, $79218
The second line contains the address of the first of the two ADCs read, with a $0 in the first hex digit.
For the Acc-51P, the ADC address is two higher than the channel base address used in the first line; for
the Acc-51E and 51C, it is five higher.
Common source addresses for the ADCs are:
Acc-51P as Servo IC 2, channels 1 – 4: $78202, $78206, $7820A, $7820E
Acc-51E as Servo IC 4, channels 1 – 4: $79205, $7920D, $79215, $7921D
The third line is a 24-bit bias term that is subtracted from both 24-bit words containing the ADC values
(even though the ADCs only occupy the top 14 bits) before the arctangent calculations are done.
The encoder counter used must be set up for times 4 decode by setting variable I7mn0 for the encoder
channel to 3 or 7. If this variable is changed, for example to change the direction sense of the counter, the
new value must be saved and the Turbo PMAC reset in order for this conversion to work properly (for the
direction sense of the fractional data to match the directional sense of the whole-count data).
channel to 3 or 7. If this variable is changed, for example to change the direction sense of the counter, the
new value must be saved and the Turbo PMAC reset in order for this conversion to work properly (for the
direction sense of the fractional data to match the directional sense of the whole-count data).