SIMATIC S7-300. DIGITAL INPUT SM 321. OPTICALLY ISOLATED. 32 DI. 120V AC. 1 X 40 PIN
SIMATIC S7-300. DIGITAL INPUT SM 321. OPTICALLY ISOLATED 16 DI. 120/230V AC. 1 X 20 PIN
SIMATIC S7-300. DIGITAL INPUT SM 321. OPTICALLY ISOLATED 16DI. 24 V DC. SOURCE INPUT. 1 X 20 PIN
SIMATIC S7-300. DIGITAL INPUT SM 321. OPTICALLY ISOLATED. 16 DI. DC 48-125V. 1 X 20 PIN