S7-200 Standard Expansion Modules

Expand your S7-200 compatible PLC system with digital I/O, analog I/O and temperature measurement modules. This page helps you quickly select the right module by signal type and application.

S7-200 Compatible Plug-in Expansion Machine Retrofit Friendly
Quick Selection Guide
Need more sensors & actuators?
Choose Digital I/O modules for push buttons, proximity sensors, solenoids and relays.
Need transmitter signals?
Choose Analog I/O for 0–10V / 4–20mA signals (pressure, flow, level).
Need temperature control?
Choose RTD (PT100) or Thermocouple (K-type) modules for heaters and ovens.
Tip: Share your PLC model + required DI/DO/AI/AO/Temp channels, we will recommend the best BOM.

Digital I/O Expansion Modules

Expand discrete inputs and outputs for sensors, push buttons, limit switches, solenoid valves, contactors and relays. Choose transistor output modules for high-speed switching, and relay output modules for general-purpose loads.

Resource Description 24V Power Supply Dimensions (L×W×H, mm) Order Number
EM221-I8 8 inputs × 24VDC Not required 46×80×62 6ES7 221-1BF22-0XA8
EM221-I16 16 inputs × 24VDC Not required 71.2×80×62 6ES7 221-1BH22-0XA8
EM221-I32 32 inputs × 24VDC Not required 137.3×80×62 6ES7 221-1BL22-0XA8
EM222-TQ8 8 outputs × 24VDC Not required 46×80×62 6ES7 222-1BF22-0XA8
EM222-RQ8 8 relay outputs Required 46×80×62 6ES7 222-1HF22-0XA8
EM222-TQ16 16 outputs × 24VDC Not required 71.2×80×62 6ES7 222-1BH22-0XA8
EM222-RQ16 16 relay outputs Required 71.2×80×62 6ES7 222-1HH22-0XA8
EM222-TQ32 32 outputs × 24VDC Not required 137.3×80×62 6ES7 222-1BL22-0XA8
EM222-RQ32 32 relay outputs Required 137.3×80×62 6ES7 222-1HL22-0XA8
EM223-I4TQ4 4 inputs × 24VDC, 4 outputs × 24VDC Not required 46×80×62 6ES7 223-1BF22-0XA8
EM223-I4RQ4 4 inputs × 24VDC, 4 relay outputs Required 46×80×62 6ES7 223-1HF22-0XA8
EM223-I8TQ8 8 inputs × 24VDC, 8 outputs × 24VDC Not required 71.2×80×62 6ES7 223-1BH22-0XA8
EM223-I8RQ8 8 inputs × 24VDC, 8 relay outputs Required 71.2×80×62 6ES7 223-1PH22-0XA8
EM223-I16TQ16 16 inputs × 24VDC, 16 outputs × 24VDC Not required 137.3×80×62 6ES7 223-1BL22-0XA8
EM223-I16RQ16 16 inputs × 24VDC, 16 relay outputs Required 137.3×80×62 6ES7 223-1PL22-0XA8
Selection Tips:
  • Relay output modules (RQ) are recommended for general loads; external 24V power supply is Required.
  • Transistor output modules (TQ) are suitable for high-speed switching; 24V power supply is typically Not required.
  • Need help? Send your required DI/DO channel count and load type, we will recommend the best module set.

Analog I/O Expansion Modules

Add analog input/output channels for industrial transmitters and control signals. Typical applications include pressure/flow/level transmitters, PID control, VFD speed reference, and valve positioning. All modules in this section use 24VDC power supply.

Resource Description Power Supply Dimensions (L×W×H, mm) Order Number
EM231-AI4 4 analog inputs 24VDC 71.2×80×62 6ES7 231-0HC22-0XA8
EM231-AI8 8 analog inputs (current type) 24VDC 71.2×80×62 6ES7 231-0HF22-0XA8
EM232-AQ2 2 analog outputs 24VDC 46×80×62 6ES7 232-0HB22-0XA8
EM232-AQ4 4 analog outputs 24VDC 71.2×80×62 6ES7 232-0HD22-0XA8
EM235-AI4AQ1 4 analog inputs, 1 analog output 24VDC 71.2×80×62 6ES7 235-0KD22-0XA8
Selection Tips:
  • Analog Inputs (AI) are used for transmitters such as pressure/flow/level (typically 4–20mA or 0–10V).
  • Analog Outputs (AQ) are used for control signals such as VFD reference, valve control, and PID outputs.
  • EM231-AI8 is current type (commonly used for 4–20mA applications).
  • Need help? Send your signal type (0–10V / 4–20mA) and channel count, we will recommend the best module.

Temperature Modules (RTD / Thermocouple)

Temperature measurement modules are designed for heating and thermal process applications. Choose RTD modules for higher accuracy and stability (commonly PT100), or Thermocouple modules for wider temperature ranges. All modules in this section use 24VDC power supply.

Resource Description Power Supply Dimensions (L×W×H, mm) Order Number
EM231-RTD4 RTD expansion module, 4 inputs 24VDC 71.2×80×62 6ES7 231-7PC22-0XA8
EM231-TC4 Thermocouple expansion module, 4 inputs 24VDC 71.2×80×62 6ES7 231-7PD22-0XA8
EM231-TC8 Thermocouple expansion module, 8 inputs 24VDC 71.2×80×62 6ES7 231-7PF22-0XA8
Selection Tips:
  • RTD (PT100) is recommended when you need higher accuracy and stable measurements in common industrial temperature ranges.
  • Thermocouple (TC) is recommended for wider temperature ranges and high-temperature applications.
  • Choose TC4 for standard small systems, or TC8 when you need more channels in one module.

How to Choose the Right Module

Step 1 — Identify Signals
List your required channels: DI / DO / AI / AO / Temp (RTD or TC).
Step 2 — Check Channel Count
Choose 4/8/16 channels based on cabinet space and wiring convenience.
Step 3 — Match Application
Relay vs transistor, voltage vs current, RTD vs thermocouple—choose by load type and environment.
Need a fast recommendation?
Send us your PLC model and the required DI/DO/AI/AO/Temp channels. We will propose a complete BOM (CPU + modules + wiring) for your project.