PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1791-24B8 is a Block I/O 1791 I/O module designed for distributed automation. This device provides 24 DC inputs alongside 8 DC outputs within a single enclosure. The 24 inputs are arranged into three groups of eight points. The block operates on an external supply voltage between 19.2 and 30 Volts DC. It requires an external operating current of 300 milliamps.
This module handles signal conversion in industrial environments between 0 and 60 degrees Celsius. Operating relative humidity ranges from 5 to 95 percent non-condensing. The hardware produces a maximum power dissipation of 17.1 Watts. Maximum thermal dissipation equals 58.1 BTU per hour. It mounts in horizontal or vertical cabinet orientations to suit specific control enclosures.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| Category | PLCs |
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| External Power | 19.2 to 30 Volts DC |
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| Input Off-state Current | 1.5mA min. |
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| Input Off-state Voltage | 5 Volts DC max. |
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| Input On-state Current | 11mA at 30 Volts max. |
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| Input On-state Voltage Range | 10 to 30 Volts DC |
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| Inputs per Block | 24 |
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| Output Voltage Range | 10 to 30 Volts DC |
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| Outputs per Block | 8 |
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| Product Lifecycle Status* | Discontinued/Obsolete |
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| UPC | 612598124794 |
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| Voltage | 24 Volts DC |
|---|
| Weight | 2.00 lbs (0.91 kg) |
|---|
TECHNICAL INFORMATION
Features
- Integrated architecture housing 24 digital inputs and 8 digital outputs in one block.
- Input grouping configured in three distinct sections of eight points each.
- Selectable input filter delays with fast and slow response options.
- Internal protection on the external DC power supply connections.
- Orientation-dependent output current ratings for vertical and horizontal installations.
TECHNICAL INFORMATION
Applications
- Distributed digital field device monitoring and actuation in PLC networks.
- High-density discrete sensor interfacing in automated production machinery.
- Industrial control enclosures requiring combined input and output points.
TECHNICAL INFORMATION
Connections / Interfaces
- Three groups of eight discrete DC input terminals.
- Eight discrete DC output load connection terminals.
- External 24 Volt DC power supply terminals.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the module in a clean industrial enclosure free of airborne contaminants.
- Derate output current based on horizontal or vertical installation orientation.
- Maintain ambient operating temperatures between 0 and 60 degrees Celsius.
TECHNICAL INFORMATION
Configuration Guidelines
- Configure input filter delays for fast or slow operation based on signal noise.
- Verify external supply voltage remains within the 19.2 to 30 Volt DC limit.
TECHNICAL INFORMATION
Compatibility
- Compatible with Allen-Bradley Block I/O 1791 architecture systems.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- The 1791-24B8 module is classified as discontinued and obsolete by the manufacturer.
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSCompatible with Allen-Bradley Block I/O 1791 architecture systems.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What is the channel configuration of the Allen-Bradley 1791-24B8?
The module includes 24 DC inputs arranged in three groups of eight, plus eight DC outputs.
What external power does the 1791-24B8 require?
The block requires an external supply voltage between 19.2 and 30 Volts DC at 300 milliamps.
How does mounting orientation affect the output current rating?
Vertical mounting supports 500 milliamps to 1 Amp between 30 and 60 degrees Celsius. Horizontal mounting supports 250 to 500 milliamps.
What is the lifecycle status of the 1791-24B8?
The 1791-24B8 is discontinued and obsolete. It remains available through surplus and legacy automation inventory channels.
