Siemens 6ES7431-7KF10-0AB0 SIMATIC S7-400 SM 431 8AI Resistance/PT100 16-Bit PLC I/O Module

The Siemens 6ES7431-7KF10-0AB0 is a SIMATIC S7-400 SM 431 analog input module with 8 isolated resistance/PT100/NI100 channels at 16-bit resolution and a 20 ms conversion time. It supports Pt100, Pt200, Pt500, Pt1000, Ni100, and Ni1000 resistance thermometers with three- or four-wire connection and parameterizable diagnostic and limit-value alarms.

Technical Specifications

Selection Notes

Use the four-wire connection over three-wire when lead resistance must be fully compensated for the tightest accuracy; the module holds +/-0.2 degrees C basic error at 25 degrees C but that widens to +/-1 degrees C operational error across the full temperature range, so budget accordingly for close-tolerance process loops. All six RTD types (Pt100 through Ni1000) are parameterizable per channel independently, so mixed sensor types can share one module rather than requiring separate cards per RTD class.

Applications

Fits precision temperature monitoring on rack-based S7-400 systems using RTD sensors: motor winding temperature, furnace and oven zone control, and process temperature loops where 16-bit resolution and multi-RTD-type support reduce the number of module types needed on one rack.