Honeywell FX-USI-0002

Technical Specifications

• Host Bus Interface: Honeywell FX internal backplane expansion bus direct plug-in connection
• External Serial Communication Port: Isolated RS485 two-wire serial terminal port
• Supported Serial Protocols: Modbus RTU Master, Modbus RTU Slave, Honeywell proprietary Fieldbus serial protocol
• Isolation Voltage Rating: 2500 V DC galvanic isolation between PLC backplane and external serial port
• Maximum Serial Communication Baud Rate: 115200 bps configurable
• Operating Supply Power: Derived directly from FX PLC base unit backplane bus (no external power required)
• Module Power Consumption: 1.2 W maximum draw from controller backplane
• Ambient Operating Temperature Range: 0 °C to +55 °C
• Module Form Factor: Standard FX series vertical stackable expansion module footprint
• Storage Temperature Range: -20 °C to +70 °C

Functional Features

1. Full galvanic electrical isolation eliminates ground loop communication bus fault risks
2. User-selectable Modbus master or slave communication operation mode
3. Onboard communication fault diagnostic register accessible via FX PLC program logic
4. Plug-in stackable backplane mounting without auxiliary wiring between controller CPU and module
5. Front panel LED diagnostic indicators: Module Power OK, Serial Bus Activity, Communication Fault
6. Parameter configuration accessible via Honeywell FX programming software suite

Material Composition

• Module Housing: UL94-V0 flame retardant reinforced polycarbonate plastic
• Internal Communication PCB: FR4 multi-layer isolated printed circuit board
• RS485 Transceiver Chip: Industrial isolated differential serial driver IC
• Backplane Connector Pins: Gold-plated phosphor bronze corrosion resistant contacts
• Terminal Block Insulator: High-temperature PBT plastic terminal assembly

Structural Characteristics

• Vertical stackable modular design compatible with all FX series CPU base units
• Single edge backplane male connector for direct insertion into controller expansion slot
• Front panel dedicated LED diagnostic status indicators for on-site troubleshooting
• Side-mounted screw terminal block for field RS485 serial bus wiring connection
• Interlocking plastic side latches to secure stacked expansion module assembly

Working Principle

Advantage Highlights

1. Backplane powered design eliminates external DC power supply hardware for communication expansion
2. 2500 V isolation rating prevents transient voltage surge damage to PLC CPU core unit
3. Native dual Modbus master/slave operation supports mixed third-party field device networks
4. Stackable modular architecture allows multiple FX-USI-0002 modules installed per single FX controller
5. Integrated diagnostic fault registers enable automated communication failure detection in control program logic

Applicable Industries

Installation Requirements

1. Power down entire FX PLC base unit before inserting or removing FX-USI-0002 expansion module
2. Align backplane connector edge fully with controller expansion slot and seat module until side latches engage
3. Torque RS485 serial bus terminal block screws to 0.7 N·m; use shielded twisted pair serial cable wiring
4. Maintain minimum 10 mm vertical clearance between stacked expansion modules for heat dissipation
5. Connect serial bus cable shield single-point grounded at control cabinet earth bus terminal

Usage Precautions

1. Never insert or remove module while FX controller base unit is energized; permanent backplane circuit damage occurs
2. Do not connect serial bus cables carrying voltage exceeding 24 V DC to RS485 terminal block
3. Configure communication baud rate and protocol matching all connected remote Modbus field instruments
4. Replace module immediately if communication fault LED remains continuously illuminated with verified intact serial wiring