Allen-Bradley 1747-BSN SLC 500 Backup Scanner Hot Standby Module

Product Overview

The Allen-Bradley 1747-BSN is a Backup Scanner Module that provides hot-standby redundancy for SLC 500 systems (5/02 and higher). It supports backup of Remote I/O (RIO) or Data Highway Plus (DH+) networks and includes a high-speed serial link for data synchronization between primary and secondary processors.

Key Specs

• Function: Hot-standby / backup scanner
• Supported networks: RIO or DH+ (switchable)
• Additional channel: RS-232/485 switchover for operator interfaces
• Link: High-Speed Serial Link (HSSL) for primary-to-secondary data transfer
• Compatible processors: SLC 5/02 and later
• Max logical racks: Up to 4 on the RIO link
• System: One module in primary chassis + complementary module in secondary chassis

Why Choose This

• Enables processor and network redundancy
• Seamless switchover on primary failure
• Supports both RIO and DH+ backup
• High-speed data synchronization between systems

Common Questions

• What does it backup? RIO or DH+ networks plus processor control.
• How many modules? Complementary pair (primary + secondary).
• Processors? SLC 5/02 or higher.

Mounting Steps

1. Install one 1747-BSN in the primary chassis and one in the secondary chassis.
2. Connect the High-Speed Serial Link between the two modules.
3. Configure switches for baud rate, address and network type (RIO/DH+).
4. Connect RIO or DH+ media and optional operator interface cable.
5. Power up both systems and verify primary/secondary status and failover.

Buying Advice

• Required in pairs for a complete backup system.
• Confirm switch settings match the network speed and addressing.
• Essential for high-availability SLC 500 Remote I/O or DH+ applications.