FOXBORO FBM215 HART® Communication Output Module

FOXBORO FBM215 HART® Communication Output Module

DESCRIPTION

The HART Communication Output Module (FBM215) contains eight channel-isolated outputs. The FBM215 supports any mix of standard 4 to 20 mA devices and HART devices (the signals are electrically compatible). The FBM215 can serve as a HARTcommunications field device host, enabling Foxboro™ DCS to request and receive two digital messages per second from the field device. The message pass-through capability can be used to support HART universal, common practice, and device-specific commands, but it cannot support the burst communication mode. These commands are implemented using the Foxboro DCS Field Device Expert for HART. For details, see Field Device Expert for HART Devices Control and I/O (PSS 41S-10FDMHRT)

Features

• 8 channel-isolated output channels, each providing one of the following outputs: 

◦ Standard 4 to 20 mA analog output signal ◦ Digital HART Frequency Shift Keying (FSK) signal superimposed on a 4 to 20 mA analog output signal 

• FSK modem dedicated to each output channel for bi-directional digital communications with a HART field device 

• Galvanic isolation of all output channels from each other, and from ground and module logic 

• Support for HART universal commands necessary to interface the field device with the Foxboro DCS database 

• Rugged design suitable for enclosure in Class G3 (harsh) environments 

• Termination Assemblies (TAs) for locally or remotely connecting field wiring to the FBM215

Standard Design

The FBM215 has a rugged extruded aluminum exterior for physical protection of the circuits. Enclosures specially designed for mounting the Foxboro DCS Fieldbus Modules (FBMs) provide various levels of environmental protection, up to harsh environments per ISA Standard S71.04.

Visual Indicators

Light-emitting diodes (LEDs) incorporated into the front of the module provide visual indication of the module’s operational status, and communication activity of the channels.

Functional Specifications

Field Device Channels

• Supported HART Instrument Types: HART instruments compliant to Version 5, 6, or 7 of the HARTspecifications may be used 

• Interface: 8 isolated output channels 

• Communications to the Device: Point-to-point, master/slave, asynchronous, half-duplex, at 1200 baud 

• Error Checking: Parity on each byte, and one CRC check byte on each message 

• Speed: 2 messages per second 

• Fastest Allowed ECB Block Period: 100 msec - However, we recommend that you see the Sizing Guidelines and Excel Workbook appropriate for your Control Processor to determine the optimal loading for a 100 msec Block Processing Cycle (BPC). 

• Maximum Distance (FBM215 to Field Device): Meets HART FSK physical layer specification HCF_SPEC-54, Revision 8.1 [up to 3030 m (10000 ft)]

• Current Outputs: 

◦ Analog Accuracy (Includes Linearity): ±0.05% of span (between 4 mA and 20 mA) 

◦ Output Load: 750 Ω maximum 

◦ Maximum Rate of Change: 20 mA in 60 milliseconds 

◦ Resolution: 13 bits 

• Loop Power Supply Protection: Each channel is channel-to-channel galvanically isolated, current limited, and voltage regulated. All analog outputs are limited by their design to about 25 mA. If the output FETshorts, the output current could increase up to 100 mA. In normal operation the FBM outputs a constant current into a 0 to 750 Ω load.

Power Requirements

• Input Voltage Range (Redundant): 24 V dc +5% 

• Consumption: 7 W (maximum) 

• Heat Dissipation: 5 W (maximum)

Temperature

• Module: -20 to +70°C (-4 to +158°F) 

• Termination Assembly — PA (Polyamide): -20 to +70°C (-4 to +158°F)

Relative Humidity：5 to 95% (noncondensing)

Altitude：-300 to +3,000 m (-1,000 to +10,000 ft)

Vibration：7.5 m/s2 (0.75 g) from 5 to 500 Hz