Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Executing Individual Motor Moves
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ENDWHILE
WHILE (M333=0)
WHILE (M333=0)
;Waits for home motion to complete
ENDWHILE
ENDIF
I323=-10
I323=-10
; Home speed 10 cts/msec negative direction
I326=0 ; No home offset
I7232=3 ; Capture on rising flag and rising index
I7233=0 ; Use Home3 as flag
CMD"#3HM"
I7232=3 ; Capture on rising flag and rising index
I7233=0 ; Use Home3 as flag
CMD"#3HM"
; Do actual homing move
WHILE (M345=1)
; Waits for home search to start
ENDWHILE
WHILE (M333=0)
WHILE (M333=0)
; Waits for home motion to complete
ENDWHILE
DIS PLC12
DIS PLC12
; Disables PLC once home is found
CLOSE
; End of program
Storing the Home Position
Turbo PMAC automatically stores the encoder position that was captured during the latest homing search
move for the motor. This value is kept in the Motor Encoder Home Capture register [Y:$CE (Motor 1),
Y:$14E (Motor 2), etc., suggested M-variable Mxx73], which is set to zero on power-up/reset for motors
without absolute power-on position. If the position reference is obtained by reading an absolute sensor
(Ixx10>0) such as from a resolver, this register holds the negative of the absolute position read. In either
case, it contains the difference between the encoder-counter zero position (power-on position) and the
motor zero (home) position, scaled in counts.
Turbo PMAC automatically stores the encoder position that was captured during the latest homing search
move for the motor. This value is kept in the Motor Encoder Home Capture register [Y:$CE (Motor 1),
Y:$14E (Motor 2), etc., suggested M-variable Mxx73], which is set to zero on power-up/reset for motors
without absolute power-on position. If the position reference is obtained by reading an absolute sensor
(Ixx10>0) such as from a resolver, this register holds the negative of the absolute position read. In either
case, it contains the difference between the encoder-counter zero position (power-on position) and the
motor zero (home) position, scaled in counts.
There are two main uses for this register. First, it provides a reference for using the encoder position-
capture and position-compare registers. These registers are referenced to the encoder zero position, which
is the power-up position, not the home (motor zero) position. This register holds the difference between
the two positions. This value should be subtracted from encoder position (usually from position capture)
to get motor position, or added to motor position to get encoder position (usually for position compare).
capture and position-compare registers. These registers are referenced to the encoder zero position, which
is the power-up position, not the home (motor zero) position. This register holds the difference between
the two positions. This value should be subtracted from encoder position (usually from position capture)
to get motor position, or added to motor position to get encoder position (usually for position compare).
Example: To move an axis until a trigger is found, then convert the captured encoder position to a motor
position, you can use the following M-variable definitions:
position, you can use the following M-variable definitions:
M103->X:$078003,24,S
; Servo IC 0 Channel 1 position-capture register
M117->X:$078000,17
; Servo IC 0 Channel 1 position-capture flag
M125->Y:$0000CE,24,S
; Motor 1 encoder position offset register
Now you can use a motion program segment like the following:
INC
; Incremental moves
TM10 TA10
; Move segment time 10 msec
WHILE (M117=0)
; While no trigger to capture position
X0.2
; Command next move segment
ENDWHILE
P103=M103-M125
P103=M103-M125
; Read captured position; subtract offset to
; get motor position at trigger
The second use for this register is to determine whether the encoder counter has lost any counts. This can
be done by performing a second homing search move after an operation, and comparing the contents of
the register after the second homing search move to the contents after the first homing search move.
be done by performing a second homing search move after an operation, and comparing the contents of
the register after the second homing search move to the contents after the first homing search move.
Jog-Until-Trigger Moves
The jog-until-trigger function permits a jog move to be interrupted by a trigger and terminated by a move
relative to the position at the time of the trigger. It is similar to a homing search move, except that the
motor zero position is not altered, and there is a specific destination in the absence of a trigger.
relative to the position at the time of the trigger. It is similar to a homing search move, except that the
motor zero position is not altered, and there is a specific destination in the absence of a trigger.