歐姆龍OMRON光電傳感器E3S-RS30E42 General-purposeMiniatureSensorsShortresponsetime:3ms.EasyadjustmentofsensitivityandopticalaxiswithSTABILITYandLIGHTindicators.Wire-selectableoperationmode.Mutualinterferenceprotectivecircuiteliminatescrosstalk(reflectivesensoronly).