Omron SYSMAC CJ Operation Manual page 36

Motion sequence and axes
Note
1-8-1 Profile generator
1-8-2 Position loop
1-8-3 Axis sequence
24
All non allocated axes are set as a virtual axis. The value for the parameter
ATYPE is 0.
Every axis has the general structure as shown in the illustration above .
The motion sequence which will be executed at the beginning of each servo
period will contain the following elements:
1 Transfer any moves from BASIC process buffers to motion buffers (see
section 1-9).
2 Read digital inputs.
3 Load moves. (See note.)
4 Calculate speed profile. (See note.)
5 Calculate axis positions. (See note.)
6 Execute position servo. For axis 0 this also includes the Servo Driver
communications. (See note.)
7 Update outputs.
Each of these items will be performed for each axis in turn before moving on to the next
item.
Basic Program
.........
.........
MOVE(1000)
.........
.........
The profile generator is the algorithm that calculates the demanded position
for each axis. The calculation is made every motion sequence.
The profile is generated according to the motion instructions from the BASIC
programs.
The position loop is the algorithm that makes sure that there is a minimal
deviation between the measured position (MPOS) and the demand position
(DPOS) of the same axis.
• The motion controller applies motion commands to an axis array that is
defined with the BASE command. If the motion command concerns one
axis, it is applied to the first axis in the BASE array. If the motion command
concerns more than one axis, and makes an orthogonal move, the axes
are taken from the array in the order defined by the BASE command. For
Profile generator
Demand Position
Section 1-8