Sensing range and output type
The Omron E3F2-7B4 is a through-beam photoelectric sensor with a 7 m sensing range and a PNP output — the emitter and receiver are separate housings, so the 7 m is the maximum separation between them in clean air. PNP sourcing output means the load connects between the output and the common (0 V) — standard for PLC input modules that sink current.