8 thermocouple inputs on a 45 mm slice
The Siemens 6ES7231-5QF30-0XB0 is a spare-part SM 1231 TC analog input module for the S7-1200 system, providing eight thermocouple inputs on a 45 mm wide DIN-rail slice. It accepts types J, K, T, E, R, S, N, and C, plus TXK/XK(L), with a ±80 mV voltage range — covering the common process and high-temperature thermocouple families in a single module. Rated supply is 24 V DC, typical power loss 1.5 W, and the module carries CE and FM approvals for industrial control panels.
Thermocouple types and diagnostic depth
The module supports thermocouple types J, K, T, E, R, S, N, and C, with a parameterizable cold-junction compensation accuracy of ±1.5 °C. Diagnostic alarm and wire-break detection are built in, and the diagnostics function can be read out over the backplane — useful for fault isolation on a line without pulling the module. The measurement principle is integrating, and the input range is ±80 mV, which covers the full output span of standard thermocouples at process temperatures.
DIN-rail footprint and ambient range
Dimensions are 45 mm wide, 100 mm high, and 75 mm deep — it occupies one S7-1200 slot width and mounts directly on the DIN rail alongside the CPU and other signal modules. Atmospheric pressure range is 795 hPa to 1080 hPa, covering altitudes up to about 2000 m without derating.