Description

Configured for analog signal generation and redundant HART data processing in Foxboro I/A Series DCS platforms, the Invensys FBM218 P0922VW (FBM218 communication output module) provides direct physical/electrical execution. The hardware operates across eight channel-isolated outputs to convert internal controller commands into 4 to 20 mA analog currents while supporting concurrent HART digital communication. Communicating with associated FCM or FCP modules via a redundant 2 Mbps HDLC fieldbus, a paired module assembly functions in a Master and Tracker configuration to ensure continuous output loop execution.

Hardware Specifications

Process Control & Channel Isolation Dynamics

The Invensys FBM218 P0922VW provides channel-to-channel galvanic isolation across all eight output loops to protect digital backplane electronics against field ground loops and voltage transients. Supporting 4-20 mA HART loop protocol standards across versions 5, 6, and 7, the module drives output currents up to a maximum load impedance of 750 Ohms per channel with a 13-bit resolution. The unit executes a maximum slew rate of 20 mA in 60 ms and maintains an analog output accuracy of +/-0.05 % of span, preventing control degradation in fast-acting valve positioning circuits.

Frequently Asked Questions

Q: How does module redundancy operate between paired FBM218 P0922VW units?

A: Two FBM218 P0922VW modules install on a baseplate with field outputs wired to a single shared termination assembly; one module executes as the active Master while the second module functions as the active Tracker over the redundant 2 Mbps HDLC fieldbus.

Q: What power supply parameters are required for operating the FBM218 P0922VW?

A: The module requires a nominal 24 V DC power supply operating within a tolerance range of +5 % to -10 %.

Q: What versions of the HART protocol are compatible with the FBM218 P0922VW output channels?

A: The module natively supports HART field instruments compliant with HART Protocol Versions 5, 6, and 7.

Field Installation Guidelines

Mount the Invensys FBM218 P0922VW directly onto a compatible Foxboro I/A Series modular baseplate. Before slot insertion, inspect the backplane connectors for mechanical alignment and clean away any dust or environmental contaminants. Slide the module along the baseplate card guide tracks and apply firm, even pressure until the locking mechanism fully seats into the backplane.

Connect all field output cabling via the designated termination assembly using twisted shielded pair conductors. Connect the cable shields to a single grounding bus bar at the panel entry point to eliminate circulating ground currents. Keep low-voltage signal wiring segregated from high-voltage AC lines to prevent inductive noise interference on the 4 to 20 mA output loops. Tighten all field wiring terminals to standard manufacturer torque values to ensure secure physical contact under vibration.