System Philosophy; Introduction - Omron TJ2-MC64 Hardware Reference Manual

System philosophy

2 System philosophy
2.1

Introduction

The system philosophy is centred around the relationship between:
• System architecture
• Cycle timeDrive
• 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.
2.1.1 Glossary
Motion sequence
The Motion Sequence is responsible for controlling the position of the axes.
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 0.25ms, 0.5ms, 1ms or 2ms.
Cycle time
Is the time needed to execute one complete cycle of operations in the TJ2-
MC64. The cycle time is divided in 4 time slices of equal time length, called
"CPU slots". The cycle time is 1ms if SERVO_PERIOD=0.25ms, 0.5ms or
1ms and 2ms if the SERVO_PERIOD=2ms.
CPU slots
The operations executed in each CPU slot are:
CPU slot Operation
First CPU slot BASIC and/or PLC execution
Motion Network update (if SERVO_PERIOD=0.25ms)
HARDWARE REFERENCE MANUAL
MOTION SEQUENCE
TJ2-MC64
Buffer &
Buffer &
Position Position
Program Buffer profile
profile
Loop Loop
gererator
gererator
-
TJ1 ML__
PLC TASKS
BASIC PROGRAMS
Process 0
Process 1
Process 2
...
Process 21
Comms
-
TJ1 FL02
MC I/O
Ethernet
-
TJ1 PRT/DRT/CORT
FINS
Ethernet Profibus
DeviceNET
CANopen
Built-in Via TJ1-ML__
fig. 1
AXIS TYPE AXIS TYPE AXIS TYPE
Servo Driver
Position
Position
Loop
Loop
MOTOR
Speed Loop
Speed Loop
Torque Torque
Loop
Loop
Servo Driver
Speed Loop
Torque
Loop
ENC
All other
Servo
Drivers
ENC
MOTOR
7