PNP output — what that means for your PLC input card
The E3F-23C4P1 carries a PNP (sourcing) output. That means when the sensor detects its target, it switches the positive side of the DC supply to the output line — the load (PLC input, relay coil) connects between the output and the 0 VDC common. If your input card is configured for NPN (sinking) inputs, this sensor won't pull the input low; you'd need an NPN variant or an interposing relay.