User's Manual

PMAC2 User Manual
44 Setting Up PMAC2 Commutation (Direct PWM or Sine Wave)
Preparation
Define M-variables to the hall-effect or equivalent inputs. Suggested definitions for Channel 1 are:
M124->X:$C000,20 ; Channel 1 W flag
M125->X:$C000,21 ; Channel 1 V flag
M126->X:$C000,22 ; Channel 1 U flag
M127->X:$C000,23 ; Channel 1 T flag (not usually hall-effect)
M128->X:$C000,20,4 ; Channel 1 TUVW as a 4-bit value
Make these definitions and add these variables to the Watch window (delete other variables no longer
being 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
these commands are used, 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:
#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.
Note:
On preliminary firmware versions dated before October 95 (use the DATE
command), these commands produce angles rotated -30
o
from the results shown
here. On preliminary firmware versions dated 10/5/95 or 10/16/95, these
commands produce angles rotated 180
o
from the results shown here, possibly
leading to a dangerous runaway condition. If using any of these firmware
versions, contact the factory for a free firmware upgrade.
Case (A) is the proper result for all direct PWM setups, regardless of the setting of Ix72. It is the proper
result for sine-wave output setups with Ix72<128. Case (B) is the proper result for sine-wave output
setups with Ix72>128.
Note:
If the T flag input is 1, the values of Mx28 will be 8 greater than what is shown in
the table.
Remember to clear the offsets when finished with this test:
I179=0 I129=0