Description
Foxboro FBM215 RH922VU — Product Page
Product Overview
The Foxboro FBM215 RH922VU is an eight-channel HART communication output module designed for Foxboro distributed control systems. It provides isolated 4–20 mA outputs for process-control applications while supporting bidirectional digital communication with compatible HART field devices. This combination allows a control system to regulate a field instrument through its analog signal and access supported digital information without requiring a separate communications path for every device. Typical applications include control-valve positioners, smart actuators, and other instruments that accept a 4–20 mA command.
Each channel is electrically isolated from the other output channels, ground, and module logic. This design helps limit the propagation of electrical disturbances between field loops, although it does not replace appropriate grounding, shielding, surge protection, or field wiring practices. The Foxboro FBM215 RH922VU supports standard analog devices as well as HART-compatible devices, allowing different device types to coexist across the eight channels. Its dedicated HART modem on each output supports HART versions 5, 6, and 7, with point-to-point, master/slave, asynchronous half-duplex communication at 1200 baud. The published communication rate is two messages per second, and HART burst mode is not supported.
From a maintenance and procurement perspective, the Foxboro FBM215 RH922VU should be evaluated as part of the complete DCS I/O installation, not as an isolated plug-in component. Output accuracy is specified at ±0.05% of span, resolution is 13 bits, and the maximum output load is 750 Ω. Actual loop performance still depends on the connected device, cable resistance, loop burden, and control-system configuration. The module communicates with its associated Fieldbus Communication Module or Control Processor over the redundant 2 Mbps module fieldbus.
Before replacement, verify the existing module identity, baseplate, termination assembly, termination cable, channel assignments, and HART configuration. The standard FBM215 termination assembly listed in the current product specification is RH926SP. Confirm the installed hardware arrangement before purchasing, especially in legacy systems or installations converted from earlier I/O generations.
Product Introduction — Practical Field Focus
When a control valve fails to follow its commanded position, the fault may involve the output module, loop wiring, field-device configuration, or actuator itself. The Foxboro FBM215 RH922VU provides eight isolated 4–20 mA output channels and HART communication support, giving maintenance teams both analog control capability and access to supported smart-device information.
For a replacement project, check the full module part number and installed termination hardware before removing the existing unit. After installation, validate commanded current, loop response, output loading, HART communication, and configured failure behavior under an approved commissioning procedure.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Module designation | |
| Part number | RH922VU |
| Previous designation | P0922VU |
| Manufacturer | Foxboro / Schneider Electric |
| Module function | HART communication analog output |
| Number of channels | 8 |
| Channel isolation | Galvanic isolation between channels, ground, and module logic |
| Analog output range | 4–20 mA |
| HART signal | FSK signal superimposed on the analog output |
| HART versions | 5, 6, and 7 |
| HART communication | Point-to-point, master/slave, asynchronous, half-duplex |
| HART baud rate | 1200 baud |
| HART message rate | 2 messages per second |
| HART burst mode | Not supported |
| Analog output accuracy | ±0.05% of span, 4–20 mA |
| Output resolution | 13 bits |
| Maximum output load | 750 Ω |
| Maximum output change rate | 20 mA in 60 ms |
| Fieldbus interface | Redundant 2 Mbps module fieldbus |
| Input power | 24 VDC, +5% tolerance per specification |
| Maximum power consumption | 7 W |
| Maximum heat dissipation | 5 W |
| Operating temperature | -20°C to +70°C |
| Storage temperature | -40°C to +70°C |
| Relative humidity | 5–95%, noncondensing |
| Operating altitude | -300 to +3,000 m |
| Vibration rating | 0.75 g from 5 to 500 Hz |
| Module dimensions | 102 mm H × 45 mm W × 104 mm D |
| Height including mounting lugs | 114 mm |
| Approximate module weight | 284 g |
| Mounting | Modular baseplate on DIN rail or rack arrangement |
| Standard termination assembly | RH926SP |
| Maximum termination cable length | 30 m |
| Cable connection | 37-pin D-sub at baseplate; 25-pin D-sub at termination assembly |
Specifications reflect Schneider Electric’s published product documentation. Confirm the applicable hardware revision and system configuration before using these values for engineering design.
FBM215 RH922VU
Related Products
The following Foxboro modules may be relevant when maintaining or expanding an existing DCS installation. They are not automatically interchangeable with the .
- FBM214b RH927AH — Eight-channel HART analog input module for acquiring signals from compatible field transmitters.
- FBM216b RH927AJ — Redundant-ready HART analog input module for applications requiring input redundancy.
- FBM218 RH922VW — Redundant-ready HART analog output module for output applications designed around its supported redundancy arrangement.
- FBM237 — Redundant 0–20 mA output module for analog control applications where HART communication is not the primary requirement.
- FBM244 RH927AK — Mixed HART I/O module providing four analog inputs and four analog outputs.
- FBM221 — Analog output module for standard current-output applications; verify the exact model and configuration before considering it as an alternative.
- RH926SP — Compression-type termination assembly specified for the standard configuration.
- P0922VU — Earlier part-number designation associated with the module.
Frequently Asked Questions
Q1. What is the primary function of the Foxboro ?
It provides eight electrically isolated 4–20 mA analog output channels and supports HART digital communication with compatible field devices. It is used to send control commands to instruments such as valve positioners and supported smart actuators.
Q2. Does the support HART communication?
Yes. The module supports HART versions 5, 6, and 7. Communication is point-to-point, master/slave, asynchronous, half-duplex at 1200 baud. The specified message rate is two messages per second, and burst mode is not supported.
Q3. Can the be replaced while the system is operating?
The product specification describes removal and replacement without disconnecting field termination, power, or communications cabling. That does not, by itself, establish that live removal is safe or permitted for every installed system. Confirm the approved hot-swap procedure, process risk, control strategy, and maintenance authorization before removal.
Q4. Is interchangeable with FBM218 RH922VW?
Do not assume so. The provides eight isolated HART output channels, while the FBM218 is designed for redundant-ready HART output applications. Their redundancy arrangements, termination hardware, and system configuration requirements differ. Confirm the exact application and supported hardware before selecting a substitute.
Q5. Which termination assembly is used with the ?
The current standard 200 Series specification lists RH926SP, a compression-type termination assembly. Verify the installed baseplate and wiring arrangement, particularly in legacy or converted installations, before ordering the module and accessories.
Q6. What should be checked if the analog output works but HART communication fails?
Check the HART device revision and address, loop resistance and capacitance, cable routing, grounding and shielding, device configuration, and DCS communication setup. Also confirm that the field device supports the required HART functions and that the installation does not rely on burst mode.
Q7. What should procurement verify before buying a replacement ?
Confirm the complete part number and label, hardware condition, termination assembly, cable type and length, module revision, and compatibility with the installed Foxboro DCS configuration. For used or refurbished stock, request actual photographs, test scope, test results, warranty terms, and confirmation of the supplied accessories. Do not treat a seller’s generic “tested” statement as proof of full channel or HART functionality.
Q8. Does a new require field calibration?
The published specification states that calibration of the module and termination assembly is not required. Site acceptance testing is still advisable: verify representative output-current points, connected-loop behavior, channel configuration, alarms, and HART communication where used.
