Delta Tau GEO BRICK LV Manuel D’Utilisation
Turbo PMAC User Manual
120
Setting Up Turbo PMAC-Based Commutation and/or Current Loop
Preparation
Define M-variables to the hall-effect or equivalent inputs. Suggested definitions for Channel 1 on a
PMAC2-style Servo IC are:
Define M-variables to the hall-effect or equivalent inputs. Suggested definitions for Channel 1 on a
PMAC2-style Servo IC are:
M124->X:$078000,20
; Channel 1 W flag
M125->X:$078000,21
; Channel 1 V flag
M126->X:$078000,22
; Channel 1 U flag
M127->X:$078000,23
; Channel 1 T flag (not usually hall)
M128->X:$078000,20,4
; Channel 1 TUVW as a 4-bit value
Make these definitions and add these variables to the Watch window. (Delete other variables that are no
longer monitored.) With the motor killed, move the motor slowly by hand to verify that the inputs
expected to change do change.
longer monitored.) With the motor killed, move the motor slowly by hand to verify that the inputs
expected to change do change.
Executing the Test
To map the hall-effect sensors, we will use the current-loop six-step test, or a variant of it, to force the
motor to known positions in the commutation cycle, and observe the states of the hall-effect signals. The
current-loop test shown above should force the motor right to the boundaries of the hall-effect zones. If
you use these commands, move the motor by hand a little bit at each point to observe the transition.
To map the hall-effect sensors, we will use the current-loop six-step test, or a variant of it, to force the
motor to known positions in the commutation cycle, and observe the states of the hall-effect signals. The
current-loop test shown above should force the motor right to the boundaries of the hall-effect zones. If
you use these commands, move the motor by hand a little bit at each point to observe the transition.
Force the motor to the expected mid-point of each hall-effect zone instead (or in addition). To do this, the
command sequence would be:
command sequence would be:
#1O0
; Open loop command of zero magnitude
I179=3000 I129=-1500
; Step 1: (A)-30
o
elec.; (B)150
o
elec.
I179=1500 I129=-3000
; Step 2: (A)-90
o
elec.; (B)90
o
elec.
I179=-1500 I129=-1500
; Step 3: (A)-150
o
elec.; (B)30
o
elec.
I179=-3000 I129=1500
; Step 4: (A)150
o
elec.; (B)-30
o
elec.
I179=-1500 I129=3000
; Step 5: (A)90
o
elec.; (B)-90
o
elec.
I179=1500 I129=1500
; Step 6: (A)30
o
elec.; (B)-150
o
elec.
I179=3000 I129=-1500
; Step 1: (A)-30
o
elec.; (B)150
o
elec.
Case (A) is the proper result for all direct PWM setups, regardless of the setting of Ixx72. It is the proper
result for sine-wave output setups with Ixx72<1024. Case (B) is the proper result for sine-wave output
setups with Ixx72>1024.
Remember to clear the offsets when finished with this test:
result for sine-wave output setups with Ixx72<1024. Case (B) is the proper result for sine-wave output
setups with Ixx72>1024.
Remember to clear the offsets when finished with this test:
I179=0 I129=0
It is advisable to create a table listing the values of M124 through M128 for each position. An example
table would be:
table would be:
Step M179 M129 Cycle
Pos.
Physical
Position
Position
M101
(counts)
(counts)
M126
(U)
(U)
M125
(V)
(V)
M124
(W)
(W)
M128
(TUVW)
(TUVW)
1 +3000
-1500
-30o
3:30
-9001
0 1 0 2
2 +1500
-3000
-90o
2:30
-9343
1 1 0 6
3 -1500
-1500
-150o
1:30
-9673
1 0 0 4
4 -3000
+1500
+150o
12:30
-10030
1 0 1 5
5 -1500
+3000
+90o
11:30
-10375
0 0 1 1
6 +1500
+1500
+30o
10:30
-10709
0 1 1 3
1 +3000
-1500
-30o
9:30
-11050
0 1 0 2
Note:
If the T flag input is 1, the values of Mx28 will be 8 greater than what is shown in
the table.
the table.