1746-IB8 | Allen-Bradley SLC 500 8-Point Digital DC Input Module

Overview

The Allen-Bradley 1746-IB8 is a digital DC input module designed for SLC 500 series controllers. It provides 8 isolated input channels capable of handling 24V sinking signals, enabling fast and accurate digital signal acquisition for process and machine control applications. Its compact design and low backplane current draw make it suitable for dense I/O configurations in industrial environments.

Key Features

• 8 DC sinking input channels

• Compatible with 24V DC signals (operating range 10–30V DC)

• Points per common: 8

• Fast response with maximum signal delay of 8 ms for both on and off states

• Low off-state voltage of 5 V DC and off-state current ≤1 mA

• Nominal input current: 8 mA at 24V DC

• Low power consumption: 50 mA from 5V DC backplane, 0 mA from 24V DC

• Compact form factor compatible with standard SLC 500 racks

Technical Specifications

• Manufacturer: Allen-Bradley

• Product Line: SLC 500 Series

• Part Number: 1746-IB8

• Module Type: Digital DC Input Module

• Number of Inputs: 8

• Voltage Category: 24V DC (sinking)

• Operating Voltage: 10–30V DC

• Backplane Current: 5V DC: 0.050 A, 24V DC: 0.0 A

• Maximum Signal Delay: On = 8 ms, Off = 8 ms

• Maximum Off-State Voltage: 5.0 V DC

• Maximum Off-State Current: 1 mA

• Nominal Input Current: 8 mA @ 24V DC

Application Scenarios

The 1746-IB8 module is ideal for:

• Machine automation requiring digital signal monitoring

• SLC 500 systems with moderate input channel requirements

• Interfacing with sensors, switches, and low-voltage control devices

• Applications where fast 8 ms response time ensures timely process control

FAQs

Q: Can this module handle voltages outside 24V DC?
A: The module operates reliably within 10–30V DC for sinking inputs.

Q: How fast does the module respond to input changes?
A: Both on and off signal transitions have a maximum delay of 8 ms.

Q: Is the module compatible with other SLC 500 digital input modules?
A: Yes, it integrates seamlessly with SLC 500 racks alongside other digital I/O modules.