GE 90-30/20/Micro Normally Open Contact | | , Normally Closed Contact |/| , Coil ( ) , Negated Coil (/)

4-4Series 90-30/20/Micro Programmable Controllers Reference Manual – September 1998 GFK-0467K
4
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 following 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.
|
| E1 E2 E3 E4 E5 E6 E7 E8 E9 E10
|——| |—————| |—————|/|—————|/|—————| |—————| |—————|/|—————|/|—————| |—————( )—
|
Coil —( )—
A coil sets a discrete reference ON while it receives power flow. It is non-retentive; therefore, it
cannot be used with system status references (%SA, %SB, %SC, or %G).
Example:
In the following example, coil E3 is ON when reference E1 is ON and reference E2 is OFF.
|
| E1 E2 E3
|——| |—————|/|—————————————————————————————————————————————————————————————( )—
|
Negated Coil —(/)—
A negated coil sets a discrete reference ON when it does not receive power flow. It is not retentive;
therefore, it cannot be used with system status references (%SA, %SB, %SC, or %G).
Example:
In the following example, coil E3 is ON when reference E1 is OFF.
|
| E1 E2
|——| |—————————————————————————————————————————————————————————————————————(/)—
|
| E2 E3
|——| |—————————————————————————————————————————————————————————————————————( )—
|