Yaskawa SMC–4000 - Manual (Page 276)

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SMC–4000 User Manual
Independent Axis Positioning
In this mode, motion between the specified axes is independent, and each axis follows its own profile. The
user specifies the desired
absolute position (PA) or relative position (PR) , slew speed (SP) , acceleration
ramp (AC) , and deceleration ramp (DC) , for each axis. On begin (BG) , the SMC–4000 profiler generates
the corresponding trapezoidal or triangular velocity profile and position trajectory. The controller
determines a new command position along the trajectory every sample period until the specified profile is
complete. Motion is complete when the last position command is calculated by the SMC–4000 profiler.
*Note The motor motion may not be complete when the profile has been completed, however, the
next motion command may be specified.
The BG (Begin) command can be issued for all axes either simultaneously or independently. X or Y axis
specifiers are required to select the axes for motion. When no axes are specified, this causes motion to
begin on all axes.
The SP (Speed) and AC (Acceleration) commands can be changed at any time during motion, however,
the DC (Deceleration) and PR (Position Relative) / PA (Position Absolute) commands cannot be changed
until motion is complete. Remember, motion is complete ( AM (After Motion) ) when the profiler is
finished, not when the actual motor is in position. The ST (Stop) command can be issued at any time to
decelerate the motor to a stop before it reaches its final position.
An IP (Increment Position) command may be specified during motion as long as the additional move is in
the same direction. Here, the user specifies the desired position increment, n. The new target is equal to
the old target plus the increment, n. Upon receiving the IP command, a revised profile will be generated
for motion towards the new end position. The IP command does not require a begin. Note: If the motor
is not moving, the IP command is equivalent to the
PR (Position Relative) and BG (Begin) command
combination.
Command Summary - Independent Axis
The lower case specifiers (x,y) represent position values for each axis. The SMC–4000 also allows use of
single axis specifiers such as PRY=2000.
Command Description
PR x,y Specifies relative distance
PA x,y Specifies absolute position
SP x,y Specifies slew speed
AC x,y Specifies acceleration rate
DC x,y Specifies deceleration rate
BG XY Starts motion
ST XY Stops motion before end of move
IP x,y Changes position target
IT x,y Time constant for independent motion smoothing
AM XY Trippoint for profiler complete
MC XY Trippoint for "in position"