User's Manual

Turbo PMAC User Manual
122 Setting Up Turbo PMAC-Based Commutation and/or Current Loop
The description of Ixx81 in the Software Reference Manual shows the common values of offsets used, for
all the cases where the zero point in the hall-effect cycle is at a 0
o
, 60
o
, 120
o
, 180
o
, -120
o
, or -60
o
point –
where manufacturers generally align the sensors.
Note:
Ixx81 in Turbo is used for address only (i.e. same as Ixx25). Ixx91 in Turbo is
used for bits 16-21, 22 and 23.
Note that Ixx75 is not used for the phase position offset in this method. It can be used to store the final
correction based off fine phasing.
Overall Procedure Summary
The full phase reference then consists of the following steps:
1. Do a rough phase reference using the hall-effect sensors as specified by Ixx81, either automatically
on power-up/reset if Ixx80=1, or on the $ command if Ixx80=0.
2. Do a homing search move on the motor, using the index pulse as part of the home trigger.
3. Wait for the motor to settle “in-position” (following error less than Ixx27) at the home position using
the motor in-position status bit – suggested M-variable Mxx40 – [WHILE(M140=0)...]
4. Force the motor phase position register to the pre-determined value at this point with a command like
Mxx71=Ixx75.
PLC-Based Hall-Effect Reference
Alternately a power-on PLC program could be used to do the hall-effect phasing. This is useful if extra
error trapping is desired, or if sensors of a different format are used.
A program based on the results of our example table would be:
;****************** Set-up and Definitions ********************
CLOSE ; Make sure all buffers are closed
M148->X:$0000C0,8,1 ; Motor 2 phasing error fault bit
M171->X:$0000B4,0,24,S ; Motor 2 phase position register
;****************** Program to do phasing search **************
OPEN PLC 1 CLEAR
M148=1 ; Tentatively set phasing error bit
IF (M128&7=2) ; Hall Effect State 1 (0 to -60 deg)?
M171=I171/-12 ; Set phase angle to -30 deg
P170=1 ; Phasing OK flag
ENDIF
IF (M128&7=6) ; Hall Effect State 2 (-60 to -120 deg)?
M171=I171*-3/12 ; Set phase angle to -90 deg
P170=1 ; Phasing OK flag
ENDIF
IF (M128&7=4) ; Hall Effect State 3 (-120 to -180 deg)?
M171=I171*-5/12 ; Set phase angle to -150 deg
P170=1 ; Phasing OK flag
ENDIF
IF (M128&7=5) ; Hall Effect State 4 (180 to 120 deg)?
M171=I171*5/12 ; Set phase angle to 150 deg
P170=1 ; Phasing OK flag
ENDIF
IF (M128&7=1) ; Hall Effect State 5 (120 to 60 deg)?
M171=I171*3/12 ; Set phase angle to 90 deg
P170=1 ; Phasing OK flag
ENDIF
IF (M128&7=3) ; Hall Effect State 6 (60 to 0 deg)?