FOXBORO FBM230 Serial Communication Module

Technical Specifications:

• Number of Ports: 2 independent serial ports
• Port A: RS-232 (DB-9 connector)
• Port B: RS-232 or RS-485 (configurable via DIP switches)
• Baud Rate: 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 bps
• Data Bits: 7 or 8
• Parity: None, Even, Odd
• Stop Bits: 1 or 2
• Protocol Support: Modbus RTU, Modbus ASCII, DF1 Master/Slave
• Max Cable Length (RS-485): 1200 meters at 9600 bps
• Max Cable Length (RS-232): 15 meters at 19200 bps

Functional Features:

• Simultaneous dual-port communication with independent configuration
• Modbus master and slave operation on each port
• DF1 protocol support for Allen-Bradley device communication
• Auto-baud detection capability
• Built-in 15kV ESD protection on all serial ports
• Optical isolation on RS-485 port (500V isolation)
• Diagnostic LEDs for TX, RX, and fault status per port

Performance Parameters:

• Isolation Voltage (RS-485): 500V RMS between port and backplane
• Isolation Voltage (RS-232): 250V RMS between port and backplane
• MTBF: Greater than 150,000 hours
• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to 85°C (-40°F to 185°F)
• Relative Humidity: 5% to 95% non-condensing

Material Composition:

• Chassis: Galvanized steel with epoxy powder coating
• PCB: FR-4 glass epoxy, conformal coated
• Connectors: DB-9, gold-plated contacts
• Isolation Barriers: Opto-isolators with silicone encapsulation

Structural Features:

• Form Factor: Standard I/A Series module, single-width
• Mounting: DIN rail or chassis mounting via backplane connector
• Dimensions (W x H x D): 25.4mm x 160mm x 120mm (approximate)
• Weight: Approximately 0.35 kg (0.77 lb)

Working Principle:
The FBM230 uses UART (Universal Asynchronous Receiver/Transmitter) chips with opto-isolation barriers for RS-485 communication. Data is received from the serial port, buffered in on-board FIFO memory, and transferred to the I/A Series backplane via the system bus interface. The module operates as a protocol translator, converting between serial data frames and I/A Series internal data format.

Advantages & Highlights:

• Dual independent ports allow simultaneous communication with two different devices
• Wide baud rate range supports both legacy and modern serial devices
• Optical isolation provides excellent noise immunity in industrial environments
• DF1 protocol support enables direct integration with Allen-Bradley PLCs

Applicable Industries:

• Oil and Gas
• Chemical Processing
• Power Generation
• Water Treatment
• Manufacturing (batch and continuous)

Installation Requirements:

• Mount in a location free from electromagnetic interference (EMI) sources
• Use shielded twisted-pair cable for RS-485 connections
• Terminate RS-485 bus with 120Ω resistor at both ends
• Ensure proper ground reference for RS-232 connections
• Configure DIP switches before powering up

Usage Precautions:

• Do not exceed 115200 bps on RS-232 ports
• Do not mix RS-232 and RS-485 devices on the same bus without proper conversion
• Verify baud rate, parity, and stop bit settings match the connected device
• Use surge protectors for outdoor or lightning-prone installations