Emerson PaCSystems VersaMax Series, Руководство пользователя

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User Manual Chapter 10
GFK-1503F Jan 2020
Instruction Set Reference 155
Normally Open Contact -| |-
A normally open contact acts as a switch that passes power flow if the associated reference
is ON (1).
Normally Closed Contact -|/|-
A normally closed contact acts as a switch that passes power flow if the associated reference
is OFF (0).
Example
The example shows a rung with 10 elements having nicknames from E1 to E10. Coil E10 is
ON when reference E1, E2, E5, E6, and E9 are ON and references E3, E4, E7, and E8 are OFF.
Figure 141
Continuation Coils and Contacts
Continuation coils and continuation contacts are used to continue relay ladder rung logic
beyond the last column. The state of the last executed continuation coil is the flow state
used on the next executed continuation contact. If the flow of logic does not execute a
continuation coil before it executes a continuation contact, the state of the contact is no
flow. There can be only one continuation coil and contact per rung; the continuation contact
must be in column 1, and the continuation coil must be in the last column.
10.7.2 Relay Functions Coils
Coils are used to control discrete references. Conditional logic must be used to control the
flow of power to a coil. Coils cause action directly; they do not pass power flow to the right.
If additional logic in the program should be executed as a result of the coil condition, an
internal reference for the coil, or a continuation coil/contact combination may be used. Coils
are always located at the rightmost position of a line of logic:
Figure 142