Allen-Bradley 1734-IB8S Safety Input Module

 

 

Product Overview

The 1734-IB8S is an 8-channel safety digital input module from the Allen-Bradley POINT Guard I/O system.

It is designed for industrial safety circuits, used to monitor devices such as:

• Emergency stop buttons (E-Stop)
• Safety gates and interlocks
• Light curtains (OSSD signals)
• Safety switches and guards

Key Specifications (confirmed)

• Brand: Allen-Bradley (Rockwell Automation)
• Series: POINT Guard I/O (1734)
• Model: 1734-IB8S
• Type: Safety digital input module
• Inputs: 8 channels
• Input Type: Current sinking (24 VDC safety inputs)
• Input Voltage Range: 11–30 VDC
• Safety Level: Up to SIL 3 / PL e (system dependent)
• Reaction time: ~16 ms class
• Test outputs: 4 pulse test channels (for fault detection)
• Function: dual-channel / single-channel safety input modes

What Makes It a “Safety” Module

Unlike a normal digital input module:

• It continuously tests wiring integrity using pulse signals
• It can detect:
  • short circuits
  • cross-wiring
  • open circuits
  • channel mismatch faults

If a fault occurs:

• The system forces the input to a safe OFF state immediately

Working Principle

The module works with safety devices like this:

1) Standard safety input (E-Stop)

• 2 channels (redundant contacts)
• Module checks both channels match

2) OSSD devices (light curtain)

• Device sends switching pulse signals
• Module verifies signal integrity

3) Internal diagnostics

• Pulse test outputs monitor external wiring
• Any abnormal condition → safety fault

Key Features

• 8 safety-rated inputs in one module
• Supports dual-channel safety architecture
• Built-in pulse testing for wiring diagnostics
• Detects cross faults and short circuits
• Compatible with GuardLogix / safety PLC systems
• Designed for Category 3 / 4 safety systems

Advantages

• High safety integrity (SIL3 / PL e capable system use)
• Advanced wiring fault detection (reduces hidden failures)
• Supports modern safety devices (OSSD light curtains)
• Strong diagnostics (helps maintenance quickly locate faults)
• Modular POINT I/O system (easy expansion)

Applications

• Emergency stop circuits
• Machine guarding systems
• Safety door interlocks
• Light curtain monitoring
• Industrial robotic safety zones
• Conveyor safety systems