Instruction manual

8. OUTPUT MODULES
8 − 58
Stroke amount
Stroke lower limit
Current value within 1 cam shaft revolution = 0
Feed current value when
M3214+20n is ON
(bottom dead center)
0
Nc
−
1
1 cycle
• After the system is started and cam's bottom dead center alignment is
completed, YnE must be switched ON the first time REAL to VIRTUAL
mode switching occurs.
Once the bottom dead center setting has been designated, it is not
necessary to switch M3214+20n ON when subsequent REAL to
VIRTUAL mode switching occurs.
(The bottom dead center position is stored in the backup memory.)
2) When the cam reference position setting signal (M3214+20n) is OFF
• When the following condition exists, operation is continued with the
stroke lower limit value and current value in 1 cam shaft revolution from
the previous VIRTUAL mode operation adopted.
(Final servo command value in previous VIRTUAL mode operation) −
(current servo current value) ≤ (in-position)
• When the following condition exists, operation is continued with the
stroke lower limit value from the previous VIRTUAL mode operation
being adopted, and the current value in 1 cam shaft revolution
calculated based on the current feed current value.
[Current value in 1 cam shaft revolution calculation]
The stroke ratio (y) is first calculated as follows:
(Feed current value) = (stroke) × (stroke ratio) × (stroke lower limit value)
The cam table for the designated cam No. is then searched (from the
beginning of a cycle), and the current value in 1 cam shaft revolution which
corresponds to the relevant point is calculated.
Because the search for the current value in 1 cam shaft revolution is always
conducted from the beginning of a cycle, beware of cases where the same
stroke ratio appears more than once in the cycle.
(Make the necessary position adjustment when switching from the REAL to
VIRTUAL mode occurs.)
Nc
−
1
Stroke amount
Stroke lower limit
value
1 cycle (1 cam shaft revolution)
32767
y
A
B
In the figure at left, there are 2 relevant
points (A and B) for the calculated stoke
ratio "y", but only point "A" is recognized.
Stoke
ratio