System philosophy
HARDWARE REFERENCE MANUAL
31
Revi
si
on 3.0
2.5
Cycle time
fig. 17
All processes in the Trajexia system are based on the cycle time.
The cycle time is divided into four CPU tasks:
•
250
μ
s time intervals for a
SERVO_PERIOD
of 0.5 and 1.0ms
•
500
μ
s time intervals for a
SERVO_PERIOD
of 2.0ms
The processes that can be carried out in each time interval
depends on the
SERVO_PERIOD
that is set.
fig. 18
The operations executed in each CPU task are:
2.5.1
Servo period
The
SERVO_PERIOD
can be set at 0.5, 1 or 2ms. The processes
that take place within the cycle time depend on the setting of the
SERVO_PERIOD
parameter. The
SERVO_PERIOD
parameter is a
Trajexia parameter that must be set according to the system
configuration.
The factory setting is 1ms (
SERVO_PERIOD=1000
). A change is
set only after a restart of the TJ1-MC__.
Cycle time = 1ms
250
μ
s
1
2
3
4
Cycle time = 2 ms
500
μ
s
1
2
3
4
CPU task
Operation
First CPU task
Motion Sequence
Low priority process
Second CPU task
High priority process
Third CPU task
1
Motion Sequence (only if SERVO_PERIOD=0.5ms)
LED Update.
High priority process
Fourth CPU task
External Communications
1
Note
The Motion sequence execution depends on setting of
the
SERVO_PERIOD
parameter.
I51E-EN-03.book Seite 31 Donnerstag, 28. Juni 2007 1:05 13