OVERVIEW

Official designation: Allen-Bradley 1791-8BC (Block I/O, Combination Discrete Input/Output Module)

Role/Application: This 16-point module provides 8 discrete 24V DC inputs and 8 discrete 24V DC outputs for distributed control applications over the Remote I/O network.

KEY SPECS SUMMARY

Power: 19.2 to 30V DC external, 300 mA current draw

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

Indicators: Individual channel LED indicators, OK LED

Operating Temp: 0 degrees C to plus 60 degrees C

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

Limit: Output current varies by mounting: Vertical 1A at 30 degrees C, Horizontal 500 mA at 30 degrees C

Lifecycle: Discontinued/Obsolete

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the maximum input current for the 1791-8BC DC discrete inputs?

A: Maximum input current is 11.0 mA at 30V DC.

Wiring & Installation:

Q: What is the recommended mounting position for the 1791-8BC to maximize output current?

A: Vertical mounting is recommended for maximum output current rating.

Troubleshooting & Compatibility:

Q: What is the voltage isolation rating between the power supply and the RIO link on the module?

A: Isolation between the power supply and the RIO is rated at 500V AC.

Replacement & Upgrades:

Q: When was the Allen-Bradley 1791-8BC combination I/O module officially discontinued?

A: The 1791-8BC was officially discontinued by the manufacturer on June 30, 2015.