ALLEN-BRADLEY 1747-SN PLC Remote I/O Scanner Module 1747SN

Description:

The Allen‑Bradley 1747‑SN PLC remote I/O scanner module is used in industrial control systems to manage communication between a PLC and distributed I/O networks. Commonly installed in legacy SLC 500 and PLC‑5 systems to scan remote I/O racks, allowing distributed sensors and actuators to interface with the central controller. Maintenance teams and system integrators use this module for network expansion, system upgrades, and replacement of failed communication modules.

Applications:

The Allen Bradley 1747‑SN scanner module is widely used in factory automation environments that require distributed I/O networking with centralized control. It is commonly found in assembly lines, conveyor systems, packaging machinery, and process automation where remote I/O racks enable flexible machine layouts, reduced cabling, and improved control architecture for distributed sensors and actuators.

Technical Specifications:

• Model: 1747‑SN
• Function: Remote I/O scanner interface for SLC 500/PLC‑5 systems
• Protocol support: DH‑485 remote I/O communications
• Backplane interface: 1747 rack mounting
• Supported I/O racks: 1794 FLEX I/O (with scanner support)
• Communication speed: Up to 115.2 kbaud (DH‑485)
• Indicators: Status LEDs for run, error, and communication
• Mounting: DIN rail or panel via PLC rack
• Compatibility: Allen‑Bradley SLC 500, PLC‑5 with appropriate firmware
• Designed for: Remote I/O scanning and distributed network communication
• Power: Supplied via PLC backplane

Common Replacements:

• Allen‑Bradley 1785‑DN2 (Data Highway Plus interface)
• Allen‑Bradley 1794‑SCNR2 (FLEX I/O scanner)
• Alternative Ethernet‑based remote I/O module (EtherNet/IP)