IAI America ACON-CY - Manual (Page 84)

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5. Operation Using I/O Signals
5.3.8 Examples of Tact Time Reduction Combining Zone Outputs and 3 Stop Points
This section explains how the tact time is reduced differently between an application with two stop points only,
and an application with three stop points where zone output signals are also used.
z 2 Stop Points
Assume that Machine M has completed processing. If there are two stop points, the vertical axis rises from the
condition shown above, and thereafter the carry-in side cannot move toward the front end unless it is
confirmed that the carry-out side is at the rear end.
Machine M stands by during the sequence of “Carry-out side drops
o Carry-out side rises o Carry-out side
moves backward o Carry-out side is confirmed to be at the rear end o Carry-in side moves forward o
Carry-in side is confirmed to be at the front end o Carry-in side drops o Carry-in side rises.”
Because there are only two stop points, the up/down heights must also be aligned between the actuators.
z 3 Stop Points Combined with Zone Output Signals
If there are three stop points, the carry-in side can move to the intermediate point regardless of the condition of
the carry-out side. Also, a desired passing point can be set using a zone output signal. In the above example,
when the Zone I signal turns ON while the carry-out side is rising, Machine M becomes operable and the
carry-out side can move backward. When the Zone II signal turns ON, the carry-in side can move forward. As
both actuators can move independently, the tact time can be reduced.
Because there are three stop points, there is no need to align the up/down heights between the actuators and
a desired layout can be implemented.
Control is also simple. When the carry-out side is inside the contact range (the Zone II signal is OFF), the
carry-in side is moved to the intermediate point if currently at the top end with the chucks closed. If the Zone II
signal turns ON during the aforementioned movement, the command is switched to one that moves the
carry-in side toward the front end. Since the carry-in side moves all the way to the front end, the tact time can
be further reduced.
[Carry-out actuator] [Carry-in actuator]
Rear end Front end Front end Rear end
Machine M
[Carry-out actuator]
Rear end Front end Front end Rear end
Machine M
[Carry-in actuator]
Zone II
Intermediate
point
Intermediate
point
Zone I