OVERVIEW

Official designation: Allen-Bradley 1791-24BR (Block I/O, Mixed Input/Output Module)

Role/Application: This module provides 24 sinking DC inputs and 8 relay outputs for distributed control, supporting 10 to 30V DC operation in Remote I/O industrial systems.

KEY SPECS SUMMARY

Power: 19.2 to 30V DC external, 14.5 Watts dissipation

Interfaces / Ports: Remote I/O link, two terminal strips

Indicators: Twenty-four Input LEDs, Eight Output LEDs, Status LEDs

Operating Temp: 0 degrees C to plus 60 degrees C

Platform / Compatibility: PLC-2, PLC-3, PLC-5, and SLC family processors

Limit: Output contact rating is 1 Ampere at 120V AC/30V DC

Lifecycle: Discontinued/Obsolete

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the minimum off-state current for the 24 DC inputs on the 1791-24BR module?

A: The input off-state current is specified to be a minimum of 1.5 mA.

Wiring & Installation:

Q: What are the primary dimensions of the 1791-24BR module in inches?

A: The overall dimensions are approximately 6.95 inches wide by 4.35 inches high by 3.85 inches deep.

Troubleshooting & Compatibility:

Q: What is the isolation rating between the power supply and the I/O groups on the 1791-24BR?

A: The module provides 500V AC isolation for power supply to RIO, I/O group-to-group, and I/O group-to-logic.

Replacement & Upgrades:

Q: Does the 1791-24BR require a termination resistor, and if so, for which communication setup?

A: A termination resistor (150 Ohm) is required if the module is the last device on the Remote I/O communication link.