SM323 EXTEND MODULE (6ES73231BL000AA0) SIMATIC S7-300, DIGITAL MODULE SM 323, OPTICALLY ISOLATED, 16 DI AND 16 DO, 24V DC, 0.5A, AGGREGATE CURRENT 4A, 1X40 PIN AND SIMATIC S7-300, FRONT CONNECTOR (6ES73921CM000AA0) FOR SIGNAL MODULES FASTCONNECT, (INSUL. PIERC. CLAMPS), 40-PIN