Delta Tau GEO BRICK LV User Manual

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Turbo PMAC User Manual 
126 
Setting Up Turbo PMAC-Based Commutation and/or Current Loop 
I279=P279 
; Restore real bias to B 
IF (ABS(P271)>I271/12) 
; Greater than 1/12 cycle? 
  M248=0 
; Clear phasing error bit 
  CMD"#2J/" 
; Close servo loop 
ELSE 
; Not enough movement 
  CMD"#2K" 
; Bad phasing, kill 
  SEND"PHASING FAILED" 
DISABLE PLC 1 
; Keep from executing again 
CLOSE 
WARNING:  
Make sure an algorithm of this type can be executed reliably.  Do not attempt this 
algorithm if the position sensor or drive is unpowered or faulted.  Turbo PMAC 
does not permit the open-loop enabled state required for this PLC if it is into 
overtravel limits.  The automatic overtravel limit functions may have to be 
disabled with Ixx13, Ixx14, and Ixx24.  Special logic may be required to step out 
of a limit before the full phasing can be done.  Remember that improper phase 
referencing can lead to runaway conditions.  Make sure that both Turbo PMAC 
fatal following error limit Ixx11 and amplifier overcurrent fault protections are 
active and working. 
Final Phase Correction with Index Pulse 
To make the final phase correction, move the Turbo PMAC motor to the index pulse and force the value 
obtained during the fine phasing test into the phase position register.  Before doing this, the 
position/velocity servo loop must be reasonably tuned; the tuning for this loop is the same as for any other 
PMAC motor. 
Usually the move to the index pulse will be the homing search move, where the trigger for the home 
position includes the leading edge of the index pulse; typically the first index pulse inside the home flag 
pulse.  I-variables I7mn2 and I7mn3 control the home trigger.  Typically the preliminary phasing will 
permit a reasonable move all the way to the home position.  It is also possible to perform a preliminary 
homing search to the first index pulse, correct the phase, and then do the real homing search. 
Once arriving at a known position in the commutation cycle, use the SETPHASE command to force a 
predetermined value into the phase position register.  When the SETPHASE command is executed, the 
value in motor parameter Ixx75 is copied into the phase position register immediately.  The SETPHASE 
command can be used as an on-line command, in a motion program, or in a PLC program. 
A sample motion program segment that performs the homing search and phase correction is: 
HOME1 
; Command homing search move 
WHILE (M140=0) WAIT 
; Loop until in position 
SETPHASE 
; Force value into phase position register