SIMATIC S7‑200 22x CPU, 6ES7 231‑7PC22‑0XA0

Here’s a detailed overview of the Siemens 6ES7 231‑7PC22‑0XA0 (EM 231 analog input module):

? Module Overview

This is a spare-part analog input module (EM 231) designed exclusively for the SIMATIC S7‑200 22x CPUs. It handles 4 analog input channels specifically for resistance thermometer (RTD) sensors or plain resistance measurements, with high precision (15‑bit + sign)

⚙️ Supported Sensor Types

• RTD (Resistance Thermometers):
  Supports Pt100, Pt200, Pt500, Pt1000, Pt10000, Ni100, Ni120, Ni1000, and Cu10
• Input resistance: 10 MΩ (across all sensor types)
• Plain Resistance:
  Ranges of 0–150 Ω, 0–300 Ω, and 0–600 Ω supported

⏱️ Conversion & Accuracy

• Measurement principle: Sigma‑Delta converter
• Update time (all 4 channels):
  ~810 ms for standard RTDs; ~1400 ms when using Pt10000
• Resolution: Up to 16 bit including sign
• Precision: ±0.05 % repeatability; overall error limit ±0.1 %
• Noise suppression:
  85 dB at 50/60/400 Hz; 120 dB common‑mode interference suppression

? Electrical Specs

• Supply current:
  – From L+ (24 V): ≤ 60 mA
  – From backplane 5 V bus: ≤ 87 mA
• Power dissipation: ~1.8 W; only ~1 mW consumed by sensor itself
• Maximum input voltage: 30 V DC
• Sensor cable length: Up to 100 m shielded

? Connectivity & Diagnostics

• Terminal type: Push-in I/O terminals via S7‑200 backplane (no field wiring terminals)
• Diagnostics LEDs:
  – EXTF (red) for sensor error
  – SF (red) for group fault
• Electrical isolation: Each analog input channel is isolated up to 500 V AC from system power and other channels

?️ Physical & Lifecycle Info

• Weight: ≈ 177–210 g; Dimensions: 71.2 × 80 × 62 mm
• Lifecycle:
• Discontinued: Since 1 October 2024; still available as a spare-part, no direct replacement
• Compliance: RoHS, WEEE; contains lead and other REACH-registered substances

✅ Who It’s For

• Users with S7‑200 22x CPU systems needing precise RTD or resistance inputs.
• Suitable for industrial temperature measurement, small continuous control loops, or OEM applications requiring accurate ±0.1 % sensor data.
• Being a spare-part, ideal for maintenance, replacement, or extension of legacy S7‑200 installations.

? Quick Specs Summary