The SRI8000-4A0B-E coupler is a field-type IO-Link master module with the Modbus-TCP\S7-TCP bus protocols and 4 IO-Link interfaces, with 4 channels of Class A/Class B configurable; maximum 8 DI channels, PNP type, and maximum 4 DO channels, NPN/PNP configurable (DI, DO, and IO-Link protocols cannot be multiplexed on the same interface), 24 VDC power supply, auto-negotiation mechanism, auto-crossover function, and plastic housing.