The Compact FBM214b HART Communication Input Interface Module features eight individually isolated 4 to 20 mA analog input channels. It supports a mix of standard 4 to 20 mA and HART devices, making it part of the Compact 200 Series I/O subsystem. This module can also act as a HART communications field device host for Foxboro™ DCS, enabling the request and receipt of two digital messages per second from the field device. However, it does not support the burst communication mode, with commands implemented through the Foxboro DCS Field Device Expert for HART.

The FBM214b provides isolated power supplies for field devices on all eight channels. Optionally, external power supplies can be used for input channels, but when a common external power supply serves two or more channels, a Cable Balun module is required to prevent HART communication channel crosstalk.

Features

• Eight analog input channels, accepting:
  • Standard 4 to 20 mA analog sensor signals
  • Digital HART Frequency Shift Keying (FSK) signals superimposed on 4 to 20 mA analog input signals
• Dedicated FSK modem for each input channel for bi-directional digital communications with HART field devices.
• Analog to digital conversion for each 4 to 20 mA input signal from HART devices.
• Support for HART universal commands required to interface with the Foxboro DCS database.
• Per-channel galvanic isolation of all eight input channels from each other, ground, and module logic.
• Compact and rugged design suitable for Class G3 (harsh) environments.
• High accuracy achieved through sigma-delta analog-to-digital conversions for each channel.
• Termination Assembly (TA) for local or remote field wiring connection to the FBM214b.
• TA for per-channel internal and/or external loop-powered transmitters.

Compact Design

The Compact FBM214b features a narrower design compared to standard Foxboro DCS 200 Series Fieldbus Modules (FBMs). It boasts a rugged acrylonitrile butadiene styrene (ABS) exterior for circuit protection. Specifically designed enclosures for mounting FBMs offer varying levels of environmental protection, including harsh environments per ISA Standard S71.04.

High Accuracy

For precision, the module incorporates a Sigma-Delta analog-to-digital converter, providing new analog input values for each channel every 100 milliseconds.

Visual Indicators

Front-mounted light-emitting diodes (LEDs) offer visual indications of the module’s operational status and communication activity on the channels.

Easy Removal/Replacement

The module mounts on a Compact 200 Series baseplate, either DIN rail or horizontally rack-mounted, with connectors for redundant Fieldbus, independent dc power, and termination cables. The module can be removed or replaced without disturbing field device termination, power, or communication cabling.

Fieldbus Communication

A Fieldbus Communication Module or Control Processor interfaces with the redundant 2 Mbps module Fieldbus used by FBMs. The Compact FBM214b module accepts communication from either path (A or B) of the redundant 2 Mbps fieldbus, ensuring continued communication over the active path if one path fails or is switched off at the system level. In cases where an external power supply is common to two or more loops, a Cable Balun Module is necessary to maintain communication signal line balance.

For more information, please refer to the PDF:  Foxboro-FBM214B