SM321 dig_in 32x24VDC Part No: AUTW 321-1BL00 . 6ES7 321-1BL00 alternative SM321, DI 32x24VDC potential isolated. pin-compatible front connector with Siemens 6ES7 321-1BLx. More info Don't forget a 32pnt front connector! (Search Tags) S7300, S7-300, 300V, 6es7321, 6es7-321