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Phone：+86 15383419322Description
The Foxboro RH927AH (manufacturer part number P0914XH27A) is a 32-channel digital input (DI) module designed for the Foxboro I/A Series® distributed control system (DCS), now part of Emerson Automation Solutions. As a high-density, redundant-capable I/O card, the RH927AH interfaces field discrete signals—such as valve feedback, pump status, alarm contacts, and limit switches—into the DCS for monitoring, interlocking, and sequence control in continuous process environments.
Engineered for reliability in mission-critical applications, the Foxboro RH927AH features group isolation, opto-coupled inputs, and software-configurable filtering (typically 5 ms) to suppress contact bounce and electrical noise. It mounts onto the FBM207B or compatible redundant I/O baseplates, enabling seamless failover between primary and secondary controllers without process interruption. The module includes front-panel LEDs for power, module status, and per-channel activity—accelerating troubleshooting during commissioning or maintenance outages.
Widely deployed in industries where safety and uptime are paramount—including power generation, oil refining, chemical processing, and water treatment—the RH927AH supports hot-swap replacement, allowing technicians to replace faulty units without shutting down the entire I/O rack or halting plant operations.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Model | RH927AH |
| Manufacturer Part Number | P0914XH27A |
| Manufacturer | Foxboro / Emerson |
| Product Type | 32-Channel Digital Input Module |
| Compatible Baseplate | FBM207B (Redundant I/O Carrier) |
| Input Voltage Range | 18–30 V DC (nominal 24 V DC) |
| Input Type | Sinking (current-sourcing field devices) |
| Isolation | Group isolated (per 8 channels) |
| Input Filter Time | 5 ms (default, software-selectable) |
| Max Input Current | ~4 mA per channel |
| Indication | Per-channel LED + module status LEDs |
| Operating Temperature | 0°C to +60°C |
| Mounting | Plug-in to FBM207B baseplate (DIN-rail mounted chassis) |
| Certifications | CE, UL, CSA, RoHS |
| Redundancy Support | Yes (dual-redundant backplane architecture) |
Main Features and Advantages
✅ High channel density: 32 inputs in a single-width module reduce cabinet space and cost per point—ideal for large-scale plants with thousands of discrete signals.
✅ Robust noise immunity: Opto-isolation and 5 ms filtering prevent false triggering from EMI, ground loops, or inductive spikes common near motors, solenoids, or VFDs.
✅ Seamless redundancy: When installed in an FBM207B redundant carrier, the RH927AH participates in Emerson’s fault-tolerant I/O architecture—ensuring continuous data flow even if one controller fails.
✅ Hot-swap capable: Technicians can replace the module during live operation without powering down the I/O chassis, minimizing production downtime during unscheduled failures.
✅ Integrated diagnostics: Front-panel LEDs show real-time channel activity and fault conditions, while the I/A Series engineering station displays detailed health data—including open-wire detection and voltage level monitoring.
Application Field
The Foxboro RH927AH is extensively used in:
- Power plants: Monitoring boiler flame detectors, turbine trip signals, and breaker statuses.
- Oil & gas: Reading ESD (Emergency Shutdown) valve positions, compressor running status, and fire/gas alarm contacts.
- Chemical & pharmaceutical: Tracking batch sequence steps, agitator on/off states, and interlock conditions.
- Water/wastewater: Detecting pump dry-run, tank high-level alarms, and screen differential pressure switches.
- Pulp & paper: Supervising web break sensors, roll stand positions, and drive-ready signals.
Related Products
- FBM207B: Redundant I/O baseplate/carrier for RH927AH
- RH927AL: Low-voltage variant (12 V DC input)
- RH928AH: 32-channel digital output module (companion to RH927AH)
- P0914XH27A: Official Emerson order code for RH927AH
- I/A Series Workstation: Engineering & operator interface for configuration
- FBM242: Analog input module for same I/O family
Installation and Maintenance
Installation Guidelines:
- Always power off the I/O chassis before initial insertion (hot-swap only applies to replacements).
- Ensure field wiring uses shielded, twisted-pair cables grounded at one end.
- Verify correct orientation—modules are keyed to prevent misinsertion into the FBM207B.
- Confirm DIP switch settings (if any) match system configuration.
Maintenance Best Practices:
- Periodically inspect for dust accumulation on connectors and LEDs.
- Use I/A Series diagnostics to monitor input health—look for intermittent signals or low voltage levels.
- If all LEDs are off but the system reports “module OK,” check field power supply integrity.
- Store spares in anti-static bags with humidity control to preserve CMOS components.
