Delta Tau GEO BRICK LV Guide D’Exploitation
Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables
232
Table Structure: The ECT consists of a series of entries, with each entry creating one processed
(converted) feedback value. An entry in the ECT can have 1, 2, or 3 lines, with each line containing a 24-
bit setup word (I-variable) in Y-memory, and a 24-bit result register in X-memory. Therefore, each entry
contains 1, 2, or 3 of these 24-bit I-variables. The final result is always in the X-memory register
matching the last I-variable in the entry.
(converted) feedback value. An entry in the ECT can have 1, 2, or 3 lines, with each line containing a 24-
bit setup word (I-variable) in Y-memory, and a 24-bit result register in X-memory. Therefore, each entry
contains 1, 2, or 3 of these 24-bit I-variables. The final result is always in the X-memory register
matching the last I-variable in the entry.
The variables that commonly contain the address of the last line of the entry are Ixx03 Motor xx Position-
Loop Feedback Address, Ixx04 Motor xx Velocity-Loop Feedback Address, Ixx05 Motor xx Master
Position Address and Isx93 Coordinate System x Time-Base Address.
Loop Feedback Address, Ixx04 Motor xx Velocity-Loop Feedback Address, Ixx05 Motor xx Master
Position Address and Isx93 Coordinate System x Time-Base Address.
The addresses for these variables can be specified directly using the above table (e.g. I103=$3501) or
by reference to the table I-variable with the special on-line command I{constant}=@I{constant},
which sets the first I-variable to the address of the second (e.g. I103=@I8000).
by reference to the table I-variable with the special on-line command I{constant}=@I{constant},
which sets the first I-variable to the address of the second (e.g. I103=@I8000).
Entry First Line: The first line’s setup register (I-variable) in each entry consists of a source address in
the low 19 bits (bits 0 – 18), which contains the Turbo PMAC address of the raw data to be processed, a
possible mode switch in bit 19 and a method value in the high 4 bits (first hex digit), which specifies how
this data is to be processed. If the first line (I-variable) in the entry is $000000, this signifies the end of
the active table, regardless of what subsequent entries in the table (higher numbered I-variables) contain.
the low 19 bits (bits 0 – 18), which contains the Turbo PMAC address of the raw data to be processed, a
possible mode switch in bit 19 and a method value in the high 4 bits (first hex digit), which specifies how
this data is to be processed. If the first line (I-variable) in the entry is $000000, this signifies the end of
the active table, regardless of what subsequent entries in the table (higher numbered I-variables) contain.
Entry Additional Lines: Depending on the method, one or two additional lines (I-variables) may be
required in the entry to provide further instructions on processing.
required in the entry to provide further instructions on processing.
The following table summarizes the content of entries in the Encoder Conversion Table:
Method
Digit
# of
lines
Process Defined
Mode Switch
1
st
Additional Line
2
nd
Additional
Line
$0
1
1/T Extension of
Incremental Encoder
None
-
-
$1
1
ACC-28 style A/D
converter (high 16 bits,
no rollover)
0 = signed data
1 = unsigned data
-
-
$2
2
Parallel Y-word data, no
filtering
0 = normal shift
1 = unshifted
Width/Offset
Word
-
$3
3
Parallel Y-word data,
with filtering
0 = normal shift
1 = unshifted
Width/Offset
Word
Max Change per
Cycle
$4
2
“Time Base” scaled
digital differentiation
None
Time Base Scale
Factor
-
$5
2
Integrated ACC-28 style
A/D converter
0 = signed data
1 = unsigned data
Input Bias
-
$6
2
Parallel Y/X-word data,
no filtering
0 = normal shift
1 = unshifted
Width/Offset
Word
-
$7
3
Parallel Y/X-word data,
with filtering
0 = normal shift
1 = unshifted
Width/Offset
Word
Max Change per
Cycle
$8
1
Parallel Extension of
Incremental Encoder
Incremental Encoder
0 = PMAC(1) IC
1 = PMAC2 IC
-
-
$9
2
Triggered Time Base,
frozen
0 = PMAC(1) IC
1 = PMAC2 IC
Time Base Scale
Factor
-