Description

Allen‑Bradley 1757‑FFLDC4 Foundation Fieldbus H1 Linking Device

Technical Specifications

• Product Model: 1757‑FFLDC4
• Brand: Allen‑Bradley (Rockwell Automation)
• Warranty: One Year
• Input Voltage: 24 V DC external power supply, 18‑30 V DC range
• Operating Temperature: 0 °C ~ +60 °C
• Storage Temperature: ‑40 °C ~ +85 °C
• Response Time: Fieldbus H1 segment update cycle ≤100 ms
• Protection Class: IP20 ControlLogix rack‑mount module
• Accuracy Class: Fieldbus communication linking‑device grade
• Output Frequency: Not applicable
• Rated Current: Max 1.1 A @24 V DC
• Fieldbus Interface: 4 independent Foundation Fieldbus H1 segments, 31.25 kbps baud rate, IEC‑61158‑2 standard
• LAS Function: Link Active Scheduler for each H1 bus segment
• Backplane: ControlLogix 1756 backplane interface
• Software Support: RSFieldbus configuration tool; Logix function‑block data mapping
• Diagnostics: Segment communication fault, module hardware self‑test, multi‑channel status LED indicators
• Certifications: FF registered, cULus, CE, ATEX / IECEx Div2 approval
• Humidity: 5‑95 % RH, non‑condensing
• Weight: 1.25 kg
• Dimensions: 175 × 120 × 85 mm
• 

Product Overview

1757‑FFLDC4 is a 4‑channel Foundation Fieldbus H1 linking device for Rockwell ControlLogix PLC platform. It bridges Foundation Fieldbus H1 field instruments and ControlLogix controller backplane, enabling data exchange between smart field devices and Logix control logic. Each H1 segment runs independent LAS scheduling, supporting multi‑host communication and function‑block execution. RSFieldbus software handles field‑bus device configuration, parameter assignment and diagnostic monitoring. OEM production discontinued; supplied as refurbished / new‑old‑stock spare‑parts for process‑plant DCS‑PLC integration‑system maintenance projects.

Application Notes

‑ Install on standard ControlLogix rack chassis; external 24 V DC power supply is mandatory. ‑ Follow Foundation Fieldbus H1 wiring rules for segment length, spur‑length and terminator installation. ‑ Verify firmware compatibility between linking‑device and ControlLogix controller before spare‑part replacement. ‑ Not hot‑swappable; isolate 24 V DC power before module removal. ‑ Typical deployment: refineries, chemical‑plants, pulp‑and‑paper mills for Foundation‑Fieldbus‑PLC integration spare‑part stocking.