Description
Foxboro FBM238 RH927AF Product Page
Product Overview
The Foxboro FBM238 RH927AF is a 200 Series discrete I/O module used in compatible Foxboro I/A Series and Foxboro DCS installations. It combines 24 digital input channels with eight digital output channels, providing 32 discrete signal points in one module. The input channels monitor field states such as switch positions, relay contacts, and equipment status. The output channels switch compatible external-source loads for control functions such as relay actuation, equipment sequencing, and discrete process interlocks.
A key feature of the FBM238 is its ability to support different field-signal arrangements through compatible termination assemblies. Depending on the termination hardware, inputs can be configured for DC voltage monitoring or contact sensing, while the output circuits use an external field supply. The FBM238 family supports signal interfaces for different nominal field voltages through the appropriate termination assemblies and adapters. The selected termination assembly determines important details such as input conditioning, isolation, output switching limits, and field-wiring connections. Input filtering is configurable, allowing the application to suppress brief transitions or contact bounce where appropriate.
For plant engineers, the Foxboro FBM238 RH927AF is a maintenance component for installations where a combination of discrete status inputs and output commands must remain integrated with the existing DCS logic. It communicates with the associated Foxboro fieldbus communication module or controller over the module fieldbus. Before replacing a unit, confirm the installed termination assembly, the actual field voltage, input sensing method, external output supply, and channel map. Do not assume every FBM238 installation uses the same electrical arrangement: a module fitted to a voltage-monitor termination assembly may have different field connections from one configured for contact sensing. Verify the installed wiring and application records before energizing the replacement.
Product Introduction — Field Maintenance Focus
A discrete I/O replacement can fail operationally even when the module fits the baseplate. The field voltage, termination assembly, and channel assignment must all match the application. The Foxboro RH927AF provides 24 digital inputs and eight digital outputs for compatible DCS installations, making it suitable for equipment-status monitoring and discrete command signals.
Before commissioning, confirm the termination assembly type, external output supply, and input-filter settings. Test the input points and output loads individually, paying particular attention to field voltage and the termination assembly’s aggregate current limits.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Model | |
| Part number | RH927AF |
| Previous part number | P0927AF |
| Manufacturer | Foxboro / Schneider Electric |
| Product type | Discrete digital I/O module |
| Digital inputs | 24 |
| Digital outputs | 8 |
| Total channels | 32 |
| Input isolation | Group isolated; exact field isolation depends on termination hardware |
| Input signal types | Contact sensing or voltage monitoring, depending on termination assembly |
| DC voltage-monitor input | Supported with the appropriate termination assembly |
| Input ON-state, 30 VDC configuration | 15–30 VDC |
| Input OFF-state, 30 VDC configuration | 0–5 VDC |
| Maximum ON-state input current | 2.3 mA at 30 VDC |
| Module supply | 24 VDC, +5% / −10% |
| Maximum module consumption | 2.65 W at 24 VDC |
| Output source | External field supply |
| Output switching | Supported for compatible DC or AC field arrangements through specified termination assemblies |
| Input filtering | No filtering, 4, 8, 16, or 32 ms |
| Communication | Module fieldbus to associated FCM or FCP |
| Operating temperature | −20°C to +70°C |
| Storage temperature | −40°C to +70°C |
| Relative humidity | 5–95%, non-condensing |
| Mounting | Compatible FBM baseplate or approved conversion mounting structure |
| Dimensions | Approximately 102 × 45 × 104 mm; 114 mm high including mounting lugs |
| Weight | Approximately 284 g |
| Termination cable length | Up to 30 m, subject to cable type and installation |
Important specification note: Output voltage and current limits depend on the selected termination assembly. Do not use a single generic output rating for all configurations. Confirm the termination assembly’s datasheet and wiring diagram before connecting field loads.
FBM238 RH927AF
Related Products
- FBM239 RH927AG: A related 32-channel discrete I/O module with a different channel arrangement—16 inputs and 16 outputs—rather than the ‘s 24-input/8-output configuration.
- FBM207 RH914TD: A 16-channel digital input voltage-monitor module for applications requiring inputs only.
- FBM241b RH914WK: A discrete I/O variant with voltage-monitor inputs and internal-source outputs.
- FBM241c RH914WM: A related discrete I/O variant using contact-sense inputs and external-source outputs.
- FBM242 RH916TA: A digital output module for applications needing a different output-focused arrangement.
- FBM244 RH927AK: A four-input/four-output analog I/O module with HART support; it handles analog signals rather than the ‘s discrete points.
- RH924HT: A termination assembly option documented for particular expansion applications; verify the exact wiring arrangement before use.
- FCP280: A Foxboro control processor used in compatible DCS architectures; it performs controller functions and is not a direct I/O-module substitute.
These models serve different signal or system roles. Confirm the required point count, electrical interface, termination assembly, and controller compatibility before selecting an alternative.
Frequently Asked Questions
Q1. What is the Foxboro RH927AF used for?
It provides 24 discrete input channels and eight discrete output channels for compatible Foxboro DCS applications. The inputs monitor field conditions, while the outputs switch compatible field loads.
Q2. Is the a 32-channel digital input module?
No. Its 32 channels consist of 24 digital inputs and eight digital outputs. If the application requires more output channels or a different input/output ratio, check the installed point map before selecting a replacement.
Q3. Can the accept different field voltages?
The family supports multiple field-signal voltage arrangements through compatible termination assemblies and adapters. The module part number alone does not determine the complete field-voltage capability. Verify the exact termination assembly and its electrical ratings.
Q4. Can I hot-swap the ?
Do not assume online replacement is safe in every configuration. The operational impact depends on the installed DCS architecture, redundancy, output behavior, and process conditions. Follow the approved maintenance procedure and establish the safe state of affected equipment before removing the module.
Q5. Does supersede P0927AF?
Schneider Electric’s specification identifies as superseding P0927AF. Before ordering, compare the actual module label and verify compatibility with the installed baseplate, termination assembly, and system revision.
Q6. Why does the termination assembly matter?
The termination assembly provides the field interface and may determine signal conditioning, isolation, voltage compatibility, and output switching characteristics. A replacement module paired with the wrong termination hardware can cause incorrect readings or prevent field loads from operating as expected.
Q7. What should be checked if a digital input does not change state?
Check the field voltage or contact state, wiring polarity, source resistance, termination assembly, and configured filtering interval. Confirm the signal at the termination point before concluding that the itself has failed.
Q8. What should procurement verify for a refurbished ?
Request a clear label photograph showing , confirm the module’s condition and revision, and ask for functional-test evidence covering the input and output channels. Also verify warranty terms, connector condition, and compatibility with the installed termination assembly. A module-only quote should not be assumed to include the required field termination hardware.
