Siemens 6ES7231-7PB22-0XA8 RTD Analog Input Module | Replacement, Equivalent & Selection Guide
The Siemens 6ES7231-7PB22-0XA8 is a 2-channel RTD (Resistance Temperature Detector) analog input expansion module designed for the Siemens S7-200 PLC series. It supports PT100, PT1000, Ni100, Ni1000, and resistance-type sensors, making it a versatile solution for temperature measurement and process monitoring in industrial automation systems.
Technical Specifications
- Part Number: 6ES7231-7PB22-0XA8
- Series: Siemens SIMATIC S7-200
- Module Type: RTD Analog Input Expansion Module
- Number of Channels: 2 (differential)
- Sensor Types Supported: PT100, PT1000, Ni100, Ni1000, 10 kΩ NTC, Resistance (0–300 Ω / 0–3000 Ω)
- Resolution: 15-bit + sign
- Measurement Range: –200°C to +850°C (PT100); –60°C to +250°C (Ni100)
- Accuracy: ±0.1% full scale at 25°C
- Supply Voltage: 24 V DC (from CPU or external)
- Current Consumption: 60 mA (5 V DC bus); 40 mA (24 V DC)
- Isolation: 500 V AC (field side to logic)
- Dimensions (W×H×D): 46 × 80 × 62 mm
- Weight: Approx. 120 g
- Operating Temperature: 0°C to +55°C
- Storage Temperature: –40°C to +70°C
- Protection Rating: IP20
- Certifications: CE, UL, cUL, FM
Compatible Replacement & Equivalent Models
The following models are commonly evaluated as replacements or alternatives to the 6ES7231-7PB22-0XA8. Always verify electrical and software compatibility before substitution:
- 6ES7231-7PD22-0XA8 — 4-channel RTD input; same S7-200 platform, higher channel count
- 6ES7231-5PB22-0XA8 — 2-channel analog input (voltage/current); different sensor type, same form factor
- 6ES7231-5QA30-0XB0 — S7-1200 SM 1231 RTD module; requires S7-1200 CPU, not pin-compatible
- 6ES7231-5ND32-0XB0 — S7-1200 SM 1231 AI 4×16-bit; voltage/current only, no RTD
- Advantech ADAM-4015 — RS-485 RTD module; standalone, requires protocol conversion
- Wago 750-461 — 2-channel PT100 input; fieldbus-based, different backplane
Note: Cross-platform replacements require hardware re-wiring and program migration. Contact support@konmask.com for compatibility assessment.
Why Choose the Original Model
- Native S7-200 Integration: Plug-and-play expansion with STEP 7-Micro/WIN; no additional configuration drivers required.
- High Accuracy RTD Measurement: 15-bit resolution with ±0.1% accuracy ensures reliable temperature data for critical processes.
- Multi-Sensor Flexibility: Supports PT100, PT1000, Ni100, Ni1000, and resistance inputs from a single module.
- Proven Industrial Reliability: Siemens SIMATIC S7-200 platform has decades of field-proven performance in harsh environments.
- Compact Form Factor: 46 mm wide DIN-rail mount minimizes panel space.
- Genuine OEM Quality: Full Siemens warranty and lifecycle support.
Typical Applications
- HVAC temperature monitoring and control
- Industrial furnace and kiln temperature regulation
- Food & beverage process temperature measurement
- Pharmaceutical clean-room environmental monitoring
- Water treatment plant temperature sensing
- Plastic injection molding barrel temperature control
- Cold-chain logistics temperature logging
System Compatibility
- Compatible CPUs: S7-200 CPU 221, CPU 222, CPU 224, CPU 224XP, CPU 226
- Programming Software: STEP 7-Micro/WIN V4.0 SP9 or later
- Bus Connection: S7-200 I/O expansion bus (direct module-to-module connector)
- Max Modules per CPU: Up to 7 expansion modules (CPU-dependent)
- Not Compatible With: S7-300, S7-400, S7-1200, S7-1500 (different backplane and addressing)
Selection Guide
| Requirement | Recommended Model | Reason |
|---|---|---|
| 2-ch RTD, S7-200 | 6ES7231-7PB22-0XA8 ✓ | Exact match |
| 4-ch RTD, S7-200 | 6ES7231-7PD22-0XA8 | Higher channel count |
| 2-ch RTD, S7-1200 | 6ES7231-5QA30-0XB0 | S7-1200 platform |
| Voltage/Current AI, S7-200 | 6ES7231-5PB22-0XA8 | Standard analog input |
| Thermocouple input, S7-200 | 6ES7231-7PC22-0XA8 | TC-type sensor support |
Quality Assurance & Sourcing
- Source: Authorized distributor channels and verified surplus stock
- Inspection: Every unit inspected for label authenticity, firmware version, and physical condition before shipment
- Packaging: Original Siemens anti-static packaging preserved where available
- Traceability: Batch records and date codes documented on request
- Warranty: 12-month replacement warranty on all units shipped from Konmask.com
How to Order
- Confirm your S7-200 CPU model and available expansion slots
- Verify sensor type (PT100 / PT1000 / Ni100 / Ni1000 / Resistance)
- Add 6ES7231-7PB22-0XA8 to cart or contact us for bulk pricing
- Specify required quantity and delivery timeline
- Receive order confirmation with tracking within 24 hours
📧 support@konmask.com | 📞 +0086 19859288691
Replacement & Compatibility FAQ
Q: Can the 6ES7231-7PB22-0XA8 replace a 6ES7231-5PB22-0XA8?
A: No. The -7PB22 is an RTD input module; the -5PB22 accepts voltage/current signals. They are not interchangeable without sensor and wiring changes.
Q: Is this module compatible with S7-1200?
A: No. The S7-200 expansion bus is not compatible with S7-1200. For S7-1200, use the SM 1231 RTD module (6ES7231-5QA30-0XB0).
Q: Can I use PT1000 sensors with this module?
A: Yes. The 6ES7231-7PB22-0XA8 supports PT100, PT1000, Ni100, Ni1000, and resistance inputs, selectable via software configuration in STEP 7-Micro/WIN.
Q: What is the maximum cable length for RTD sensors?
A: Siemens recommends shielded 3-wire cable up to 100 m. For longer runs, use a transmitter to convert to 4–20 mA signal.
Q: Do you supply new or refurbished units?
A: Konmask.com supplies both new OEM stock and professionally tested refurbished units. Condition is clearly stated on each listing. All units carry a 12-month warranty.
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Contact: support@konmask.com | +0086 19859288691









