Description
Product Introduction & Engineering Value
The FBM214b P0927AH provides eight independently isolated 4-20 mA input channels, each equipped with its own FSK modem for HART communication. Every channel is galvanically isolated from the others, from ground, and from module logic.
It accepts any combination of conventional analog transmitters and HART devices (versions 5, 6, or 7) without external multiplexers. Individual loop power supplies are built in, so each transmitter can be powered from the module or from an external source. The card mounts on a standard 200 Series baseplate and communicates with the FCP over the redundant 2 Mbps Module Fieldbus.
Technical Specifications
| Parameter | Value |
|---|---|
| Channels | 8, individually (channel) isolated |
| Input Signal | 4-20 mA analog or HART FSK on 4-20 mA |
| HART Versions Supported | 5, 6, or 7 |
| Isolation | Channel-to-channel, channel-to-ground, channel-to-logic (600 V ac, 1 min) |
| Accuracy (includes nonlinearity) | ±0.03% of full scale |
| Temperature Coefficient | 50 ppm/°C |
| Resolution | 15 bits |
| Update Rate | 100 ms |
| Sense Resistor | 61.5 Ω nominal |
| Compliance Voltage (internal power) | 18.5 V dc minimum at 20.5 mA |
| Power Supply | 24 V dc +5% / –10% (redundant) |
| Power Consumption | 7 W maximum |
| Operating Temperature | –20 to +70 °C (–4 to +158 °F) |
| Module Weight | Approx. 284 g (10 oz) |
Field Application & The “Trench” Experience
During a planned outage at a Gulf Coast ethylene plant, six aging group-isolated HART cards were replaced with FBM214b P0927AH modules. The existing field wiring and Termination Assemblies stayed in place. After the swap, each channel retained its original 4-20 mA process value while the control system began receiving secondary variables and device status that had previously required a handheld communicator at the transmitter. No re-ranging or cable changes were needed; the only configuration step was enabling the HART ECB blocks.
Typical niche uses:
- Individually isolated pressure and differential-pressure transmitters on a multi-stage compressor train where ground potential differences exist between measurement points
- Mixed analog-only and HART density probes on a polymer reactor feed system
- Critical level transmitters on a high-purity chemical storage tank that require both continuous 4-20 mA and occasional diagnostic polling without shared isolation groups
Transparency SOP: QA & Testing
Every P0927AH unit is powered on a dual 24 V supply and verified for Fieldbus communication. Each of the eight channels is then driven with a calibrated 4-20 mA source while HART commands 0 and 3 are exchanged with a reference device. Isolation resistance is measured channel-to-channel and channel-to-logic. The module is then subjected to a temperature soak while analog accuracy and HART message integrity are continuously monitored. Only units that pass the full sequence ship.
FBM214b P0927AH
FBM214b P0927AH
The Veteran’s Tech Trap Guide
⚠️ Do not assume the Termination Assembly is the same as the older FBM214. The channel-isolated FBM214b uses a different TA family (commonly P0924JH). Installing the wrong assembly can leave channels without power or create improper return paths.
PRO TIP: When using external loop power on more than one channel, a Cable Balun module is required. Without it, HART signals can cross-talk between channels even though the analog isolation is intact.
⚠️ HART burst mode is not supported. If a field device is left in burst mode it will saturate the channel’s modem and prevent normal polled communication. Always confirm the device is set to polled (master/slave) mode before bringing the loop online.
Dynamic FAQ
Q: What is the main difference between FBM214 and FBM214b P0927AH? A: The original FBM214 is group-isolated. The FBM214b P0927AH provides full individual channel isolation and independent loop power supplies for each of the eight channels.
Q: Can I mix pure 4-20 mA transmitters and HART devices on the same P0927AH module? A: Yes. Any combination is supported on a per-channel basis.
Q: Does the module support HART version 7 devices? A: Yes. It is compatible with HART instruments compliant to versions 5, 6, or 7.
Q: Is field calibration required after installation? A: No. The module leaves the factory calibrated. No field adjustment is possible or necessary.
Q: Are New Surplus units original Schneider Electric / Foxboro product? A: Yes. Each unit is original OEM material that has completed the full analog accuracy and HART communication test sequence described above.
Q: What warranty applies? A: 12-month warranty against defects in materials and workmanship from the date of shipment for both New Surplus and fully tested refurbished units.
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