Honeywell XNXXSM1SS Smart Sensor – Modbus NO Detector

Product Overview

• Honeywell XNXXSM1SS – Smart Sensor for Nitric Oxide (NO)
• Output module with isolated RS485 for Modbus networks
• Installed in display module or by a qualified engineer
• Supports multi-drop network with up to 254 nodes

Technical Data

• Gas detected: NO (Nitrogen Monoxide)
• Default range: 100 ppm
• Lower detectable limit: 3 ppm
• Cal gas range: 30‑70% of full scale
• Default cal point: 50 ppm
• Response time (T50): <15 sec
• Response time (T90): <30 sec
• Accuracy: ±2 ppm
• Operating temperature: -20°C to 55°C (-4°F to 131°F)

Communication & Physical Layer

• Protocol: Modbus RTU
• Baud rate: 1200 to 19.2K
• Connections: RS485+, RS485-, Drain
• Isolated RS485 – robust against noise
• Max nodes: 254 XNX transmitters only

Expert Review

• “Fast, accurate NO detection for safety and process control.”
• “Isolated Modbus output simplifies integration with PLCs.”
• “Reliable even in harsh industrial environments.”
• “Easy to install and calibrate with minimal downtime.”

Manager’s Insight

• “Great value for continuous NO monitoring in plants.”
• “Recommended for emission control and worker safety.”
• “Supports long‑distance communication via RS485.”
• “Reduces wiring cost compared to analog systems.”

Applications & Compatible Devices

• Industrial exhaust stacks – emission compliance
• Chemical plants – leak detection
• Power generation – NOx monitoring
• Pharmaceutical labs – fume hood safety
• Environmental monitoring stations
• Works with any Modbus RTU master (PLC, DCS, SCADA)

Frequently Asked Questions

• Is the sensor pre‑calibrated?
  Yes, it is factory calibrated but field calibration is recommended.
• What is the cable length limit?
  Up to 1200 meters with shielded twisted‑pair cable.
• Can I use this with other gas sensors?
  No, this is specifically for Nitric Oxide (NO).
• Does it have a display?
  Only when installed in the display module (optional).
• Is the module hot‑swappable?
  No, power off before installation or removal.

Experience‑based Q&A

• Why is the reading unstable?
  Check wiring and grounding. Avoid nearby high‑voltage cables.
• How often to calibrate?
  Every 3‑6 months depending on application and environment.
• Can I change the range?
  No, the range is fixed at 100 ppm for this model.

Selection Guide

• Confirm your gas is Nitric Oxide (NO).
• Ensure your network supports Modbus RTU.
• Check temperature stays within -20°C to 55°C.
• Order a display module if local readout is needed.
• Consider spare sensors for critical applications.

Warranty, Shipping & Contact

• Warranty: 12 months from purchase date
• Dispatch: within 12‑24 hours
• Shipping: FedEx, UPS, DHL (tracked)
• Inquiries: sales@powergearx.com
• WhatsApp: +86 18030005825

Comparison with Similar Models

• Honeywell XNXXSM2SS (higher range, different gas)
• Honeywell XNXXAM1SS (analog output version)
• Honeywell XNXXFM1SS (Foundation Fieldbus option)

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