Relay Functions; Relay Functions Normally-Open, Normally-Closed, Continuation Contacts - GE VersaMax PLC User Manual

10.7 Relay Functions

174 GFK-1503E
For public disclosure
• Normally Open Contact –| |–
• Normally Closed Contact –|/|–
• Normally Open Coil –( )–
• Retentive SET Coil –(SM)–
• Retentive RESET Coil –(RM)–
• Negated Retentive Coil –(/M)–
• Negated Coil –(/)–
• Retentive Coil –(M)–
• SET Coil –(S)–
• RESET Coil –(R)–
• Positive Transition Coil –(↑)–
• Negative Transition Coil –(↓)–
• Vertical Link vert |
• Horizontal Link horz –
• Continuation Coil –––<+>
• Continuation Contact <+>–––
Each relay contact and coil has one input and one output. Together, they provide logic
flow through the contact or coil.
Input→ ——| |—— ← Output
10.7.1 Relay Functions Normally-open,
Normally-closed, Continuation Contacts
A contact is used to monitor the state of a reference. Whether the contact passes power
flow depends on the state or status of the reference being monitored and on the contact
type. A reference is ON if its state is 1; it is OFF if its state is 0.
Type of Contact
Normally Open
Normally Closed
Continuation Contact
10.7.1.1 Normally Open Contact -| |-
A normally open contact acts as a switch that passes power flow if the associated
reference is ON (1).
10.7.1.2 Normally Closed Contact -|/|-
A normally closed contact acts as a switch that passes power flow if the associated
reference is OFF (0).
10.7.1.3 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.
Display Contact Passes Power to Right:
-| |-
When reference is ON.
-|/|-
When reference is OFF.
<+>— If the preceding continuation coil is set ON.
VersaMax PLC User Manual