SIMATIC S7‑200 22x series CPU, 6ES7 235‑0KD22‑0XA8

Here’s a detailed overview of the Siemens 

6ES7 235‑0KD22‑0XA8 (EM 235 analog I/O module for S7‑200 CN):

? Module Overview

This is a spare-part analog I/O module (EM 235) designed exclusively for SIMATIC S7‑200 22x series CPUs. It provides 4 analog inputs plus 1 analog output, both configurable for voltage and current signals. It features a 12-bit (AI) and 11-bit (AO) converter and carries CE approval

⚙️ Inputs & Outputs

• Inputs (4): Differential channels supporting both voltage (ranges ±50 mV up to ±10 V) and current (0–20 mA) measurements
• Output (1): Programmable as voltage (±10 V) or current (0–20 mA), with minimum load impedance of 5 kΩ (voltage) and maximum 0.5 kΩ (current)

? Performance & Accuracy

• Resolution: AI up to 12 bits; AO up to 11 bits
• Conversion Time: <0.25 ms per channel
• Accuracy:
• Basic (25 °C): ±0.5% of full scale
• Full range: ±2%
• Suppression: 40 dB attenuation up to 60 Hz

? Electrical & Power Specs

• Power Dissipation: Approx. 2 W
• Supply Current:
• From 5 V backplane: max 30 mA
• From 24 V input: max 60 mA
• Limits:
• Max input voltage: 30 V DC
• Max input current: 32 mA

⚠️ Diagnostics & Isolation

• LED Indicator: Red EXTF light for external faults
• Isolation: No galvanic isolation between field and logic for both inputs and output

? Physical & Lifecycle

• Dimensions: 71.2 × 80 × 62 mm; Weight: ≈ 186 g
• Lifecycle: Discontinued since October 1, 2017; still available as a spare‑part
• Compliance: CE‑marked, RoHS/WEEE, contains REACH-listed lead (>0.1%)

✅ Best Use Cases

• Ideal for S7‑200 22x systems requiring mixed analog control—like process automation with both voltage and current sensors and actuators.
• Suitable for upgrades or maintenance of legacy installations, given its spare-part status.

? Quick Specifications