Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Motor Compensation Tables and Constants
177
For large amounts of extra data memory, it is recommended to use the User Buffer set up with the on-line
DEFINE UBUFFER command. The User Buffer occupies a number of registers at the high end of X/Y
data memory. With an Option 5x0 standard memory configuration, the end of data memory is at
X/Y:$0107FF; if DEFINE UBUFFER 2048 is declared, all data memory from $010000 through
$0107FF is reserved for the user’s own purposes. With an Option 5x3 extended memory configuration,
the end of data memory is at X/Y:$03FFFF; there is by default a User Buffer of 65,536 words, reserving
all memory registers from X/Y:$030000 to X/Y:$03FFFF for user use. It is the user’s responsibility to
make sure that registers in the UBUFFER utilized for Open Servo data storage are not used for other
purposes as well.
DEFINE UBUFFER command. The User Buffer occupies a number of registers at the high end of X/Y
data memory. With an Option 5x0 standard memory configuration, the end of data memory is at
X/Y:$0107FF; if DEFINE UBUFFER 2048 is declared, all data memory from $010000 through
$0107FF is reserved for the user’s own purposes. With an Option 5x3 extended memory configuration,
the end of data memory is at X/Y:$03FFFF; there is by default a User Buffer of 65,536 words, reserving
all memory registers from X/Y:$030000 to X/Y:$03FFFF for user use. It is the user’s responsibility to
make sure that registers in the UBUFFER utilized for Open Servo data storage are not used for other
purposes as well.
Writing the Open Servo Program
The Open Servo program should be written in a plain-text editor such as the editor in the new
PEWIN32PRO PMAC Executive program. While the program can be written in any plain-text editor, it
must be compiled by the PEWIN32PRO editor’s download function. In this program, released in October
2001, the download routine will recognize Open Servo routines automatically, compile them, and
download the resulting machine code. (Older versions of the PMAC Executive program are not capable
of doing this.)
PEWIN32PRO PMAC Executive program. While the program can be written in any plain-text editor, it
must be compiled by the PEWIN32PRO editor’s download function. In this program, released in October
2001, the download routine will recognize Open Servo routines automatically, compile them, and
download the resulting machine code. (Older versions of the PMAC Executive program are not capable
of doing this.)
In the file containing the Open Servo preceding the actual program must be all L-variable and F-variable
pointer definitions, and all #define macro substitutions, or #include references to accessible files
that contain these definitions and substitutions. Remember that the built-in compiler does not download
these definitions and substitutions to the Turbo PMAC; it uses them to do the compilation properly.
pointer definitions, and all #define macro substitutions, or #include references to accessible files
that contain these definitions and substitutions. Remember that the built-in compiler does not download
these definitions and substitutions to the Turbo PMAC; it uses them to do the compilation properly.
The OPEN SERVO command is a signal to the compiler that the statements following up to the (required)
CLOSE command are to be compiled into DSP machine code before downloading. The CLEAR
command that is used following the OPEN command on interpreted buffers is not required for Open Servo
algorithms, because downloading the newly compiled code automatically clears older code, but it may
still be used here.
CLOSE command are to be compiled into DSP machine code before downloading. The CLEAR
command that is used following the OPEN command on interpreted buffers is not required for Open Servo
algorithms, because downloading the newly compiled code automatically clears older code, but it may
still be used here.
Example 1: Proportional Control
The following algorithm shows one of the simplest possible Open Servo algorithms, implementing a
simple proportional control law using the motor’s Ixx30 parameter as the proportional gain.
The following algorithm shows one of the simplest possible Open Servo algorithms, implementing a
simple proportional control law using the motor’s Ixx30 parameter as the proportional gain.
OPEN SERVO
; Following lines to be compiled
CLEAR
; Not necessary, but acceptable
COPYREG P30
; Copy following error into P32
P35=P32*I(ITOF(MTRNUM*100+30))/65536
; Multiply by gain, scale
RETURN(FTOI(P35))
; Make an integer and output
CLOSE
Example 2: Bi-Quad Filter
The next example shows an implementation of a bi-quad filter capable of running on multiple motors,
storing values from cycle to cycle for each motor. It uses #define substitution macros to keep the code
readable, and the MTRNUM function for variable and register arrays to separate stored values for each
motor. Variable arrays (which are easier for the user to access) are used for user-set “gains”, and register
arrays (which are quicker for the algorithm to access) are used for algorithm-calculated stored values.
The next example shows an implementation of a bi-quad filter capable of running on multiple motors,
storing values from cycle to cycle for each motor. It uses #define substitution macros to keep the code
readable, and the MTRNUM function for variable and register arrays to separate stored values for each
motor. Variable arrays (which are easier for the user to access) are used for user-set “gains”, and register
arrays (which are quicker for the algorithm to access) are used for algorithm-calculated stored values.
This Open Servo program implements the following transfer function:
)
z
(
E
)
d
z
)(
b
z
(
)
c
z
)(
a
z
(
K
)
z
(
U
p
+
+
+
+
=
It implements this as the following difference equation:
(
)
[
]
(
)
2
k
1
k
2
k
1
k
k
p
k
bdu
u
d
b
ace
e
c
a
e
K
u
−
−
−
−
−
+
−
+
+
+
=