FOXBORO FBM201

Description

Overview
The Compact FBM201 Analog Input Interface Module contains eight analog input
channels, each channel accepting a 2-wire, 0 to 20 mA dc input from an analog
sensor. It is part of the Compact 200 Series I/O subsystem described in Compact 200
Series I/O Subsystem Overview (PSS 41H-2COV).
The modules perform the signal conversion required to interface the electrical input
signals from the field sensors to the FCP.
The FBM201 is electrically compatible with standard HARTsignals.
Features
• 8 channels for input of analog 0 to 20 mA dc sensor signals
• Each analog input channel is galvanically isolated from other channels and
ground
• Compact, rugged design suitable for enclosure in Class G3 (harsh) environments
• Execution of an analog input application program that provides conversion time
and configurable options for integration time and Rate of Change Limits
• High accuracy achieved by sigma-delta data conversions for each channel
• Termination Assemblies (TAs) for locally or remotely connecting field wiring to the
Compact FBM201 module
• Termination Assemblies for per channel internally and/or externally loop powered
transmitters
Compact Design
The Compact FBM201’s design is narrower than the standard 200 Series Fieldbus
Modules (FBMs). It has a rugged Acrylonitrile Butadiene Styrene (ABS) exterior for
physical protection of the circuits. Enclosures specially designed for mounting the
FBMs provide various levels of environmental protection, up to harsh environments
per ISA Standard S71.04.
High Accuracy
For high accuracy, the modules incorporate sigma-delta data conversion on a perchannel basis, which can provide a new analog input reading every 25 ms, and a
configurable integration period to remove any process noise and power-line frequency
noise.
Each time period, the FBM converts each analog input to a digital value, averages
these values over the time period, and provides the averaged value to the controller.
Easy Removal/Replacement
The module mounts on a Compact 200 Series baseplate. Two screws on the FBM
attach the module to the baseplate.
The module can be removed/replaced without removing field device termination
cabling, power, or communication cabling.
Visual Indicators
Red and green light-emitting diodes (LEDs) incorporated into the front of the module
provide visual status indications of the FBM operational status.
Modular Baseplate Mounting
The modules mount on a DIN rail mounted modular baseplate, which accommodates
up to 16 compact FBMs. The baseplate is either DIN rail mounted or rack mounted,
and includes signal connectors for redundant fieldbus, redundant independent dc
power, and termination cables.
Fieldbus Communication
A Fieldbus Communication Module or a Control Processor interfaces the redundant 2
Mbps module Fieldbus used by the FBMs. The FBM201 modules accept
communication from either path (A or B) of the redundant 2 Mbps fieldbus. If one path
is unsuccessful or is switched at the system level, the module continues
communication over the active path.
Termination Assemblies
Field I/O signals connect to the FBM subsystem via DIN rail mounted TAs. The TAs
used with the Compact FBM201 modules are described in Termination Assemblies
and Cables, page 10.