Description
Product Introduction
The Foxboro FBM214 RH924WA is a high-density 32-channel analog input module designed for the Foxboro I/A Series and Foxboro Evo Distributed Control Systems (DCS). Operating within the Compact 200 Series subsystem, it serves as an advanced process data collector, converting 4-20 mA DC field signals into digital values for execution inside Foxboro Field Control Processors (FCPs).
In addition to traditional 4-20 mA analog signal conversion, the RH924WA acts as a digital bridge by supporting Highway Addressable Remote Transducer (HART) protocol pass-through. This allows asset management software to continuously extract secondary field variables, diagnostic status, and calibration parameters from smart transmitters without adding auxiliary field wiring. You can deploy the module in standalone configurations or as a redundant pair for uninterrupted loop monitoring.
Key Technical Specifications
| Parameter | Value |
| Module Part Number | FBM214 RH924WA / P0924WA |
| Input Channels | 32 group-isolated analog input channels |
| Signal Range | 0 to 20 mA DC or 4 to 20 mA DC |
| HART Compatibility | HART Protocol v5, v6, and v7 pass-through |
| Analog-to-Digital Resolution | 15 bits |
| Input Accuracy | ±0.03% of full scale range (at 25°C) |
| Update Rate | 100 ms total across all 32 channels |
| Power Dissipation | ~4.5 W maximum |
| Harsh Environment Rating | ISA S71.04 Class G3 (Severe) |
| Status LEDs | Module state (Red/Green), Channel status indicators |
| Mounting Format | Compact 200 Series Baseplate (Dual retention screws) |
Application Scenarios & The “Trench” Experience
When a critical temperature or transmitter loop drops offline in the middle of a complex reaction run, the DCS loses sight of the process. In high-density analog loops, a single failing I/O channel card can blind an operator to dozens of process variables simultaneously, forcing emergency manual overrides or costly unit shutdowns.
- Oil & Gas Distillation Towers – Temperature & Pressure Monitoring – Collecting 32 continuous 4-20 mA transmitter loops across multiple tower trays into a central FCP loop block.
- Chemical Processing Facilities – Smart Transmitter Asset Management – Extracting HART diagnostics and device health metrics directly into Field Device Manager (FDM) software.
- Pharmaceutical Batch Reactors – Mass Flow & Level Control – High-accuracy 15-bit resolution ensures tight tolerances during critical dosing phases.
- Water & Wastewater Infrastructure – Main Header Flow Measurement – Monitoring remote magnetic flow meters while simultaneously polling HART secondary totals over existing signal wiring.
Field Case Study: Emergency Swap at an Ethylene Cracker Unit
During a seasonal thunderstorm, a severe ground loop surge damaged an old analog input card at a Texas cracker facility, causing 24 transmitter loops on a quench tower to drift wildly. The operators lost visibility on differential pressures, triggering immediate process alarms. A pre-tested RH924WA replacement card was pulled from surplus inventory. Maintenance technicians executed a live hot-swap on the Compact 200 baseplate in less than 10 minutes. The new module auto-bound to the FCP, instantly restored all 32 analog loops, and allowed HART diagnostic software to re-interrogate field transmitters without halting unit operations.
RH924WA
RH924WA
Transparency SOP: Quality Assurance & Testing
We do not just ship boxes; we test them on actual Foxboro 200 Series baseplates with precision signal calibrators.
- Inbound Mechanical & Pin Integrity Audit: Comprehensive physical check of backplane connector pins, mounting hardware, top/bottom retention screws, and factory serial markings.
- Baseplate Communication POST: Insertion into an active Foxboro Compact 200 baseplate to verify power-on handshakes and backplane registration.
- Multi-Channel Precision Loop Calibration: Injecting precise 4.0 mA, 12.0 mA, and 20.0 mA reference signals across all 32 channels simultaneously to verify A/D conversion accuracy (±0.03% specification).
- HART Telemetry Pass-Through Test: Polling connected HART temperature and pressure transmitters through Foxboro Field Device Manager software to verify secondary variable readouts and HART modem response.
- Redundancy Failover Verification: Testing redundant pairing using a matching adapter to confirm bumpless transfer upon simulated primary card pull.
- Anti-Static & Moisture Packaging: Sealing the verified card in heavy-duty ESD-shielding bags with moisture-absorbing desiccant prior to dispatch.
The Veteran’s Tech Trap Guide (Crucial Value-Add)
- ⚠️ Verify Transmitter Power Sources (2-Wire vs. 4-Wire): The RH924WA measures current loops, but your Terminal Assembly (TA) determines whether field transmitter loop power is supplied by the system or an external power supply. Hooking up a self-powered 4-wire transmitter to a 2-wire powered TA position will damage the input stage.
- ❗ Check HART Master Enable Settings in FCP Software: If you install the RH924WA and notice analog values reading fine but HART data is missing, check your control processor software configuration (
FBMBOUND). HART polling must be explicitly enabled in the block parameters; otherwise, the module operates in standard 4-20 mA mode only. - ⚠️ Keep Cable Shields Grounded at One End Only: When running high-density 32-channel analog wiring over long field runs, always ground cable shields at the Terminal Assembly ground bar only. Floating or double-grounded shields introduce ground loops that destroy 15-bit analog conversion accuracy.
- ❗ Confirm Redundant Slot Positioning: When deploying the in a redundant pair, always seat the modules in adjacent baseplate slots starting on an odd slot number (e.g., Slots 1 and 2). Misaligned placement prevents the redundant adapter from making proper backplane cross-connections.
Frequently Asked Questions (FAQ for Conversion)
Q: Is the FBM214 hot-swappable on a live system?
A: Yes. You can remove and replace this module on a powered 200 Series baseplate without shutting down the rack or interrupting adjacent running I/O modules.
Q: What is the difference between P0924WA and ?
A: They are identical in form, fit, and function. “P0924WA” is the primary legacy Foxboro part number, while “” designates the lead-free, RoHS-compliant version. They drop in as 1-to-1 replacements for each other.
Q: Can this module read standard 4-20 mA loops without HART devices attached?
A: Absolutely. The functions as a standard, high-precision 32-channel 4-20 mA analog input card even if non-HART analog transmitters are connected to the channels.
Q: What condition are these units sold in?
A: We stock both Factory Sealed New Surplus and fully bench-tested Clean Refurbished modules. Every unit undergoes multi-point precision calibration testing before shipping.
Q: What warranty is provided with the module?
A: All modules include a full 12-month replacement warranty starting from the date of purchase.
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