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MN05013005E
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Inside EZD
EZD Program cycle
In conventional control systems, a relay or contactor control
processes all the rungs in parallel. The speed with which a
contactor switches is thus dependent on the components
used, and ranges from 15 to 40 ms for relay pick-up and drop-
out.
With EZD the circuit diagram is processed with a
microprocessor that simulates the contacts and relays of the
circuit concerned and thus processes all switching operations
considerably faster. Depending on its size, the EZD circuit
diagram is processed cyclically every 0.1 to 40 ms.
During this time, EZD passes through six segments in
succession.
How EZD evaluates the circuit diagram:
In the first four segments EZD evaluates the contact fields in
succession. EZD checks whether contacts are switched in
parallel or in series and saves the switching states of all
contact fields.
In the fifth segment, EZD assigns the new switching states to
all the coils in one pass.
Rung
Segment
1
2
3
4
5
6
1
2
3
4
..
I 12---j------------------------Ä Q 08
I 01----I 04----HW01Q1--T 06Q1-Ä T 01EN
I 02----I 03-------------------R Q 02
T 01---u-----------------------Ä Q 01
P 01---k
