Rockwell Automation 1398-PDM-xxx IQ Master Version 3.2.4 for IA-2000 and IQ-5000 Positioning Drive Modules, IQ-55 - Manual (Page 178)

156 Motion • Stick Moves
Publication 1398-PM601A-EN-P — October 2000
TUTORIAL
Incremental (MOVD) Motion
Incremental motion is defined as a move of some distance from the current position. Move four revolu-
tions from the current position is an example of an incremental move (MOVD=4).
MOVD is the instruction in IQ Basic to create incremental moves. The simplified syntax for this
instruction is:
MOVD = distance
This instruction causes the motor to move distance from the current position. The sign (+/-) of distance
will determine which direction the motor will go. If the sign is positive the motor will spin in the posi-
tive direction. The positive direction is defined in the Parameter menu, System dialog box.
Absolute (MOVP) Motion
Absolute motion is defined as a move to some fixed position from the current position. The fixed posi-
tion is defined as a position relative to a fixed zero point. The zero point for a system is established dur-
ing a homing cycle, typically performed immediately after power-up.
During a homing cycle, the motor will make incremental moves while checking for a physical input,
index mark, or both. Once the input(s) is detected, the ULTRA Plus or IQ knows where the motor is rel-
ative to the machine and establishes a zero point. See Appendix A for more details.
MOVP is the instruction in IQ Basic to create absolute moves. The simplified syntax for this instruction
is:
MOVP = position
This instruction causes the motor to move to position from the current position. The direction the motor
moves is determined by the current position relative to the commanded position. If the command posi-
tion is greater than the current position, the motor will go in the positive direction. If it is less, it will go
in the negative direction.
Stick Moves
In addition to the simple trapezoidal or triangular velocity profiles that can be generated using the
MOVD and MOVP instructions, complex profiles can be generated using stick moves. A stick move
represents one portion of a complete move. A complete move is constructed out of two or more sticks,
starting and ending at zero velocity.
D, V Segments (Sticks)
Sticks are created using a sequence of DV and/or DIF instructions. The simplified syntax for the DV
instruction is:
D = distance, V = velocity
Distance is the length of the stick move. Velocity is the final velocity for the stick move. The starting
velocity is either zero or the final velocity of the previous stick. The final stick in a complete move must
have a velocity of zero.