PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1791-32A0 is a discrete input I/O module in the Block I/O 1791 family. This standalone remote station provides thirty-two AC input channels arranged in four isolated groups of eight channels each. It connects directly to Remote I/O networks to transfer field data to host programmable controllers. The unit operates on an external supply voltage of 85 to 132 Volts AC at 47 to 63 Hertz. Each input channel accommodates a nominal operating voltage of 120 Volts AC.
The module integrates internal signal conditioning circuitry and logic processing in a compact housing. Internal isolation provides 1250 Volts AC group-to-group and group-to-logic protection. Power supply to communication port isolation is rated at 500 Volts AC. Maximum module power dissipation is 13.62 Watts with thermal dissipation reaching 46.44 BTU per hour. Field connections attach to removable terminal strips mounted on the left and right sides of the housing.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
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| Category | PLCs |
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| UPC | 612598124800 |
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| Weight | 2.31 lbs (1.05 kg) |
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| Module Type | Discrete Input module |
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| No. of Inputs | Thirty-Two (32) Inputs |
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| No. of groups | Four (4) input groups |
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| No. of channels per group | Eight (8) |
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| Nominal input current | 11 mA |
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| Input voltage | 120VAC |
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| ON state voltage range | 79-132VAC, 47-63 Hz. |
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| Supported communication protocol | Remote I/O (RIO) |
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| External supply voltage | 85-132VAC, 47-63 HZ |
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| External supply current | 150 mA |
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| Power dissipation | 13.62 Watts |
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| Thermal Dissipation | 46.44 BTU / hr |
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| Voltage | 120V ac |
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| Inputs per Block | 32 |
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| Input On-state Voltage Range | 79-132V ac |
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| Input On-state Current | 12.3mA @ 132V max. |
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| Input Off-state Voltage | 35V max. |
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| Input Off-state Current | 2.3mA min. |
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| Outputs per Block | 0 |
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| External Power | 85-132V ac |
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| Product Lifecycle Status* | Discontinued/Obsolete |
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TECHNICAL INFORMATION
Features
- Provides thirty-two discrete AC inputs arranged in four isolated groups of eight channels.
- Integrates an onboard Remote I/O communication interface for distributed network architectures.
- Features an on-state operating range of 79 to 132 Volts AC at 47 to 63 Hertz.
- Includes removable terminal blocks on both sides for direct field wiring access.
- Incorporates status indicators for real-time monitoring of communication and individual channel states.
- Provides dual switch assemblies for configuring rack number, starting group, and communication rate.
TECHNICAL INFORMATION
Applications
- Remote digital sensing in Allen-Bradley PLC-5, PLC-3, and SLC 5/02 control architectures.
- Distributed digital input data collection across Remote I/O serial communication links.
- Control panel installations requiring compact DIN rail or panel-mounted discrete AC inputs.
TECHNICAL INFORMATION
Connections / Interfaces
- Removable terminal blocks provide connections for thirty-two discrete AC inputs, external power, and Remote I/O wiring.
- A single Remote I/O communication port supports distributed network connections.
- Accepts 14 AWG stranded copper field wiring with maximum insulation thickness of 3/64 inch.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the unit securely onto a standard DIN rail or flat panel surface inside an industrial enclosure.
- Maintain ambient operating temperatures between 0 and 60 degrees Celsius with non-condensing relative humidity below 95 percent.
- Verify external supply voltage is within 85 to 132 Volts AC before applying power.
- Configure module DIP switches for network baud rate and starting rack assignment prior to final power-up.
TECHNICAL INFORMATION
Configuration Guidelines
- Set the dual switch assemblies to configure starting I/O group, I/O rack number, and communication baud rate.
- Assign last chassis and last state parameters in accordance with the host PLC Remote I/O scanner configuration.
TECHNICAL INFORMATION
Compatibility
- Compatible with Allen-Bradley PLC-2, PLC-3, PLC-5/250, and PLC-5 programmable controllers.
- Compatible with SLC 5/02 modular controllers using standard Remote I/O scanner interfaces.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- The 1791-32A0 Block I/O module is categorized by the manufacturer as discontinued and obsolete.
- Existing installations can be serviced using verified surplus or refurbished units to maintain running control lines.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSCompatible with Allen-Bradley PLC-2, PLC-3, PLC-5/250, and PLC-5 programmable controllers. Compatible with SLC 5/02 modular controllers using standard Remote I/O scanner interfaces.
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 primary function of the Allen-Bradley 1791-32A0 module?
The 1791-32A0 is a standalone 32-point AC discrete input station communicating over Remote I/O networks.
What are the input voltage and current specifications for each channel?
Each channel operates at 120VAC nominal, with an on-state voltage range of 79 to 132VAC and 12.3mA maximum current.
How is the 1791-32A0 configured on a Remote I/O network?
Two onboard switch assemblies configure the starting I/O group, rack number, last chassis status, and communication rate.
What is the market reference pricing for the 1791-32A0?
Observed market reference prices range from $748.44 to $5,562.00 depending on condition. These figures are indicative market reference pricing only and are not a final quotation.
