Siemens LOGO! Manual page 65

Unused inputs
The circuit program automatically assigns the unused connectors a status that ensures
proper functioning of the relevant block. If you like, you can label unused connectors with an
'x' identifier.
In our example we shall use only two inputs of the OR block and two inputs of the AND
block; the relevant unused third and fourth inputs are identified at the connector with an 'x'.
Now connect the I/O to LOGO! .
Wiring
Connect the switches S1 to S3 to the screw terminals of your LOGO! :
● S1 to connector I1 of LOGO!
● S2 to connector I2 of LOGO!
● S3 to connector I3 of LOGO!
The output of the AND block controls the relay at output Q1. The load E1 is connected to
output Q1.
Wiring example
The following figure shows you the wiring, based on a 230 V AC version of LOGO!.
LOGO!
Manual, 10/2017, A5E01248535-AA
Programming LOGO!
3.4 From circuit diagram to LOGO! program
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