① Output status: normally open and normally closed. When no object is detected, the load connected by the normally open photoelectric switch does not work due to the cut-off of the output transistor inside the photoelectric switch. When an object is detected, the transistor is turned on and the load is powered on.

② Output forms: NPN two-wire, NPN three wire, NPN four wire, PNP two-wire, PNP three wire, PNP four wire, AC two-wire, AC five wire (with relay), DC NPN / PNP / normally open / normally closed multifunction and other common output forms.

③ Response frequency: the number of allowable photoelectric switch action cycles within the specified time interval of 1s.

④ Detection distance: refers to the spatial distance from the measured reference position (sensing surface of photoelectric switch) to the detection surface when the detection body moves in a certain way and the switch acts. The rated operating distance refers to the nominal value of the operating distance of the proximity switch.

⑤ Detection method: according to the different ways in which the light emitted by the transmitter is folded back to the receiver when the photoelectric switch detects objects, it can be divided into diffuse reflection type, mirror reflection type, opposite reflection type, etc.

⑥ Return difference distance: the absolute value between action distance and reset distance.

⑦ Surface reflectance: the light emitted by the diffuse reflective photoelectric switch can be reflected back to the receiver of the diffuse reflective switch only after passing through the surface of the detected object, so the detection distance and the surface reflectance of the detected object will determine the intensity of the light received by the receiver. The light intensity reflected from the rough surface must be less than that reflected from the smooth surface, and the surface of the detected object must be perpendicular to the light emitted by the photoelectric switch.