Siemens 6ES7231-5QA30-0XB0 SIMATIC S7-1200 SB 1231 TC 1 AI Thermocouple Module

The Siemens 6ES7231-5QA30-0XB0 is a SIMATIC S7-1200 SB 1231 TC signal board with one thermocouple input for Type J or K sensors, resolving temperature at up to 15 bit plus sign. It mounts on the CPU front, reads ±80 mV directly in voltage mode, and reports wire-break diagnostics at ±0.1% accuracy at 25°C over the total measurement range.

Certifications & Standards

• CE mark
• CSA approval
• UL approval
• cULus
• FM approval
• RCM
• KC approval
• Marine approval

Selection Notes

Choose the SB 1231 TC when a station needs exactly one extra thermocouple channel on a compact 1212C or 1214C CPU rather than a full SM 1231 TC module; it occupies the CPU's signal-board slot instead of a rack position. The module accepts Type J or Type K thermocouples directly and flags open-circuit sensor wiring through its diagnostics function, which matters on temperature loops where a broken junction would otherwise read as a frozen or drifting value rather than a fault. Its ±0.1% accuracy at 25°C, widening to ±0.2% up to 55°C, is adequate for process monitoring but should be checked against the application's control tolerance before specifying it for closed-loop temperature control.

Applications

Single-point temperature monitoring on ovens, extruders, or dryers built around the S7-1200, or a spare thermocouple channel added to a machine that already uses its onboard analog inputs for other signals.