Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Executing Individual Motor Moves
219
EXECUTING INDIVIDUAL MOTOR MOVES
Once the motor is defined and basically working with reasonable gains, command some basic moves for
the motor. Jogging commands make simple moves for the motor, independent of other motors, without
writing a motion program. Use these moves for development, diagnostics, and debugging, but they may
also be used in an actual application.
the motor. Jogging commands make simple moves for the motor, independent of other motors, without
writing a motion program. Use these moves for development, diagnostics, and debugging, but they may
also be used in an actual application.
Another type of simple motor move is the homing search move. This is basically a jog-until-trigger type
of move, where Turbo PMAC commands the motor to move until it sees a pre-defined trigger. It then
brings the motor to a stop and returns to the trigger position (possibly with an offset), and sets the motor
position to zero.
of move, where Turbo PMAC commands the motor to move until it sees a pre-defined trigger. It then
brings the motor to a stop and returns to the trigger position (possibly with an offset), and sets the motor
position to zero.
A homing search move should be performed when it is not known where home position is. If there is an
incremental position sensor, and it is not known the location on power-up; therefore, typically the homing
search move is the first move done in this type of system. However, if the home position known, but just
wish to return to that position, there is no need to do a homing search move; simply command a move to
the zero position (e.g. J=0 or X0)
The trajectories for jogging and homing moves are the same as for rapid-mode program moves.
However, these moves are specified directly to the motor, specified by number, rather than the axis,
specified by letter. The moves are described in unscaled units (all based on counts and milliseconds).
incremental position sensor, and it is not known the location on power-up; therefore, typically the homing
search move is the first move done in this type of system. However, if the home position known, but just
wish to return to that position, there is no need to do a homing search move; simply command a move to
the zero position (e.g. J=0 or X0)
The trajectories for jogging and homing moves are the same as for rapid-mode program moves.
However, these moves are specified directly to the motor, specified by number, rather than the axis,
specified by letter. The moves are described in unscaled units (all based on counts and milliseconds).
Jogging Move Control
The velocity and acceleration for jogging moves is controlled by I-variables for the motor jogged. The
destination is controlled by jog commands. These are described below.
destination is controlled by jog commands. These are described below.
Jog Acceleration
Variable Ixx20 for Motor xx specifies the acceleration time for jogging, homing, and programmed
RAPID-mode moves, in milliseconds. Ixx21 specifies the time in each half of the S-curve acceleration
profile for these moves, also in milliseconds. If Ixx20 is less than two times Ixx21, the acceleration time
used will be twice Ixx21.
RAPID-mode moves, in milliseconds. Ixx21 specifies the time in each half of the S-curve acceleration
profile for these moves, also in milliseconds. If Ixx20 is less than two times Ixx21, the acceleration time
used will be twice Ixx21.
The acceleration rate limit for jog/home/RAPID moves is set by Ixx19 (in counts/msec
2
). If Ixx20 and
Ixx21 are so small that Ixx19 would be exceeded, the acceleration time is extended so that Ixx19 is not
exceeded. To specify the acceleration by rate instead of time, set the acceleration time parameters small
enough that the limiting acceleration rate parameter is always used.
exceeded. To specify the acceleration by rate instead of time, set the acceleration time parameters small
enough that the limiting acceleration rate parameter is always used.
Note:
To specify the acceleration by rate, do not set both acceleration time parameters
Ixx20 and Ixx21 to zero. This will cause a division-by-zero error in the move
calculations that could cause erratic movement. The minimum acceleration time
setting should be Ixx20=1 and Ixx21=0.
Ixx20 and Ixx21 to zero. This will cause a division-by-zero error in the move
calculations that could cause erratic movement. The minimum acceleration time
setting should be Ixx20=1 and Ixx21=0.
Jog Speed
Jogging speed is specified by Ixx22, which is a magnitude of the velocity, in counts per millisecond.
Direction is specified by the jog command itself.
Direction is specified by the jog command itself.