6ES7231-5PF32-0XB0

Product information

The 6ES7231-5PF32-0XB0 is a Siemens SIMATIC S7-1200 analog input module: SM 1231, AI 8×16 bit RTD. It provides 8 resistance-thermometer inputs for direct temperature measurement, with 15-bit-plus-sign resolution, integrated wire-break diagnostics and a maximum destruction limit of ±35 V at the inputs.

Rather than converting an analog transmitter signal, this module reads the resistance element itself, which removes a conversion stage between sensor and controller. It supports the common industrial resistance sensors — Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100 and LG-Ni1000 — as well as direct resistance measurement in the 0–150, 0–300 and 0–600 Ω ranges, and can display values in °C or °F.

Technical specifications

Manufacturer / family	Siemens · SIMATIC S7-1200
Product type	SM 1231, AI 8×16 bit RTD
Number of analog inputs	8, resistance thermometer
Supported sensors	Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100, LG-Ni1000
Direct resistance ranges	0–150 Ω, 0–300 Ω, 0–600 Ω
Resolution with overrange	15 bit + sign
Measurement principle	Integrating
Unit selection	°C or °F, adjustable
Permissible input voltage (destruction limit)	±35 V
Supply voltage	24 V DC
Current consumption	40 mA typical from 24 V DC; 80 mA from backplane bus
Power loss	1.5 W typical
Diagnostics	Wire-break, supply-voltage monitoring, diagnostic alarm
Interference voltage suppression	85 dB at 50 / 60 / 400 Hz
Degree of protection	IP20
Approvals	CE, UL, cULus, CSA, FM, RCM, KC

Specifications as published in Siemens product data for this article number. Verify against the nameplate of the unit offered to you.

Mounting and configuration

The module mounts on the S7-1200 rail alongside the CPU and is configured in the hardware configuration of the engineering project. Sensor types and ranges are selected by DIP switch settings on the module and by the device configuration, so the switch positions and the project settings must agree. Changing the sensor type on an installed module is therefore not a purely software operation.

Typical applications

• Multi-point temperature acquisition in ovens, furnaces, dryers, chillers and heat-treatment equipment
• Machine monitoring where several RTD sensors must be read by a single controller
• Process skids needing a compact, diagnostics-enabled temperature front end
• Direct resistance measurement tasks in the 150 Ω, 300 Ω or 600 Ω ranges

Application examples describe typical uses of this product type. Suitability for your own installation must be confirmed against your engineering documentation.

Related references

• 6ES7231-5PD32-0XB0 — SM 1231 RTD with 4 analog inputs, same sensor support
• 6ES7214-1AG40-0XB0 — CPU 1214C DC/DC/DC
• 6ES7215-1HG40-0XB0 — CPU 1215C DC/DC/Relay

Before you order

To confirm a specific unit, please provide the complete ordering code, the required revision, a nameplate photograph, the quantity required and the delivery destination. Availability, condition, quantity, lead time and commercial terms are confirmed individually after inquiry.

Frequently asked questions

Is this an analog input module for voltage and current signals?
No. The AI 8×16 bit RTD version is intended for resistance thermometers and direct resistance measurement. For voltage or current signals a different SM 1231 variant is required.

Which temperature sensors are supported?
Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100 and LG-Ni1000, plus 0–150 / 0–300 / 0–600 Ω resistance ranges.

What resolution does it provide?
15 bit plus sign with overrange, using an integrating measurement principle with 85 dB suppression at 50 / 60 / 400 Hz.

Does it detect a broken sensor lead?
Yes. Wire-break and supply-voltage monitoring are available as diagnostics with a diagnostic alarm.

Can it be used with a CPU 1214C?
Yes. It is a standard S7-1200 signal module and counts against the expansion limit of the CPU it is mounted with.

What is the price and lead time?
Confirmed individually against current availability for the specific revision and quantity.