Mitsubishi MELSEC-F FX-TRN-BEG-E, Руководство пользователя

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FX-TRN-BEG-E A: Let’s Learn the FX Series PLC! 1
B-5
1.1.3 Points of Learning and Control Specifications
1) What is sequence control?
"Sequence control"
This is not a familiar term generally but sequence control happens around us every day. You
probably have seen or touched objects under sequence control.
In a dictionary*, the word "sequence" is explained as follows:
a)succession
b)connected line of events, ideas, etc.
c)the order in which they occur
d)three or more next to each other in value
* Oxford Advanced Learner’s Dictionary of Current English" (Oxford University Press)
Based on the above, we can see that the word "sequence" indicates "succession" and "the
order in which they occur".
The meaning of the term "sequence control" is derived from the word "sequence", and
indicates the control of operations in accordance with the predetermined order. The word
"control" indicates "means by which a machine, etc. is operated or regulated".
Let’s take a look at a familiar example and see how the PLC is used.
In the picture below, a door is opened and closed.
The person follows the necessary procedure and manipulates the door to allow a car to
pass through.
Opening and closing of the door (manual)
The car approaches
the door.
The person opens
the door.
The car passes
through the opening.
The person closes
the door.
Operation sequence