Siemens 6ES7231-5PB50-0XB0 Analog Input Module. Siemens 6ES7231-5PB50-0XB0 is the exact manufacturer order number for a analog input module in the SIMATIC S7-1200 portfolio. Siemens describes this exact reference as: SIMATIC S7-1200 G2, SB 1231 RTD, AI 2x RTD, Pt100 and Pt1000. The verified manufacturer lifecycle record is PM300: Active Product.