Siemens 6ES7326-1BK00-0AB0 Digital Input Module — Legacy Replacement. Siemens 6ES7326-1BK00-0AB0 is the exact manufacturer order number for a digital input module in the SIMATIC S7-300 portfolio. Siemens describes this exact reference as: SIMATIC S7, DIGITAL INPUT SM 326, 24 DI; DC 24V, 40 PIN, FAILSAFE DIGITAL INPUTS FOR SIMATIC S7F SYSTEMS, WITH DIAGNOST. INTERRUPT. The verified manufacturer lifecycle record is PM500:Discontinued Product or end of PLM & Support.