Omron SYSMAC CJ Series, Operation Manual

Page: 14 / 371

System philosophy Section 1-2
2
1-2 System philosophy
The system philosophy is centred around the relationship between:
• System architecture
• Cycle time
• Program control and multi-tasking
• Motion sequence and axes
• Motion buffers
A clear understanding of the relationship between these concepts is
necessary to obtain the best results for the Trajexia system.
1-2-1 Glossary
1-2-1-1 Motion sequence
The Motion Sequence is responsible for controlling the position of the axes.
1-2-1-2 Servo period
Defines the frequency at which the Motion Sequence is executed. The servo
period must be set according to the configuration of the physical axes. The
available settings are 0.5 ms, 1 ms, 2 ms or 4 ms.
1-2-1-3 Cycle time
Is the time needed to execute one complete cycle of operations in the CJ1W-
MCH72. The cycle time is divided in 4 time slices of equal time length, called
"CPU Tasks". The cycle time is 1ms if
SERVO_PERIOD = 0.5 ms or
SERVO_PERIOD = 1 ms, 2 ms if the SERVO_PERIOD = 2 ms and 4 ms if the
SERVO_PERIOD = 4 ms
AXIS TYPE
AXIS TYPE
AXIS CONTROL LOOP
Position
Loop
Position
Loop
Buffer &
profile
gererator
Buffer &
profile
gererator
Servo Driver
MOTOR
Position
Loop
Position
Loop
Speed Loop
Speed Loop
Torque
Loop
Torque
Loop
ENC
ENC
Program Buffer
BASIC PROGRAMS
Process 1
Process 2
Process 3
…
Process 14
Comms
CJ1W-MCH72
AXIS TYPE
ML
I/O
BUILT-IN TJ1-PLC interface
All other
Servo
Drivers