Serial Link Selector 621-9928R Honeywell Redundant SLS

Product Overview

Honeywell 621-9928R is a Serial Link Selector (SLS) module used in redundant Logic Manager configurations. It switches shared serial communication devices between primary and secondary processors under control of the Redundancy Control Module.

Technical Specs

• Type: Serial Link Selector (SLS)
• Configuration: Double-wide module
• Slots: B and C of one I/O card file per serial system
• Control: Driven by Redundancy Control Module (RCM)
• Connectors: Front-panel 12-position terminals (A, B, Out)
• Indication: LEDs show active processor (A or B)

Key Features

• Automatic switching of serial devices to the active processor
• Supports redundant Logic Manager architectures
• Front-panel status LEDs for quick diagnostics
• Detachable screw terminals for easy wiring

FAQ

• Purpose? Switch serial links in redundant systems.
• Controlled by? Redundancy Control Module.
• Width? Double-wide module.

Installation Guide

1. Install in slots B and C of the designated I/O card file.
2. Connect serial cables from processors A and B to the A and B terminals.
3. Wire the shared serial device to the Out terminal.
4. Connect the switch-select signals from the RCM.
5. Power up and verify the active-processor LED.

Selection Tips

• Required for redundant serial I/O or terminal sharing.
• Use one SLS per serial system in a redundant pair.
• Keep as a spare for high-availability Logic Manager setups.