Omron SYSMAC CJ Series, Operation Manual

Page: 16 / 371

Motion control concepts Section 1-3
4
1-3 Motion control concepts
The CJ1W-MCH72 offers these types of positioning control operations:
1 Point-to-Point (PTP) control
2 Continuous Path (CP) control
3 Electronic Gearing (EG) control.
This section introduces some of the commands and parameters used in the
BASIC programming of the motion control application.
Coordinate system
Positioning operations performed by the CJ1W-MCH72 are based on an axis
coordinate system. The CJ1W-MCH72 converts the position data from either
the connected Servo Driver or the connected encoder into an internal absolute
coordinate system.
The engineering unit that specifies the distances of travelling can be freely
defined for each axis separately. The conversion is performed through the use
of the unit conversion factor, which is defined by the
UNITS axis parameter.
The origin point of the coordinate system can be determined using the
DEFPOS command. This command re-defines the current position to zero or
any other value.
A move is defined in either absolute or relative terms. An absolute move takes
the axis (A) to a specific predefined position with respect to the origin point. A
relative move takes the axis from the current position to a position that is
defined relative to this current position. The figure shows an example of
relative (command
MOVE ) and absolute (command MOVEABS ) linear moves.
1-3-1 PTP control
In point-to-point positioning, each axis is moved independently of the other
axis. The CJ1W-MCH72 supports the following operations:
• Relative move
• Absolute move
• Continuous move forward
• Continuous move reverse.
0
50 100
A
MOVE(30)
MOVE(50)
MOVEABS(50)
MOVE(60)
MOVEABS(30)