Siemens 6ES7321-7RD00-0AB0 SIMATIC S7, DIGITAL INPUT SM 321, OPTICALLY ISOLATED, 4 DI, 24V DC (Siemens 6ES73217RD000AB0)
Siemens 6ES7322-5RD00-0AB0 SIMATIC S7, DIGITAOUTPUTL SM 322, OPTICALLY ISOLATED, 4 DO (Siemens 6ES73225RD000AB0)
Siemens 6ES7322-5SD00-0AB0 SIMATIC S7, DIGITAOUTPUTL SM 322, OPTICALLY ISOLATED, 4 DO (Siemens 6ES73225SD000AB0)