Product Overview
The 1791-24BR is a mixed I/O module from the Allen-Bradley 1791 Block I/O series. It combines 24 DC inputs with 8 relay outputs for flexible control. This module operates on 10-30V DC and supports remote I/O applications. Its compact design includes self-contained power and signal conditioning. The module mounts vertically on a DIN rail for space-saving installation.
Key Technical Specifications
- Brand: Allen-Bradley / Rockwell Automation
- Model: 1791-24BR
- Series: 1791 Block I/O
- Inputs: 24 DC (3 groups of 8)
- Input Voltage Range: 10-30V DC (on-state), 5V DC max (off-state)
- Input Current: 2.5 mA @ 10V min, 11 mA @ 30V max
- Outputs: 8 relay outputs, 20-132V AC @ 1A resistive
- External Power: 19.2-30V DC @ 300 mA
- Power Dissipation: 14.5 W max; thermal 49.4 BTU/hr
- Isolation: 500V AC (power to remote I/O, group-to-group, logic)
- Temperature: 0-60°C operating, -40-85°C storage
- Humidity: 5-95% non-condensing
- Dimensions: 6.95 x 4.35 x 3.85 inches
- Weight: 2.38 lbs (1.08 kg)
Compatibility & Installation
- Compatible with PLC-2, PLC-3, PLC-5/250, PLC-5 family, and SLC 5/02 modular controllers.
- DIN rail mounting (vertical orientation recommended).
- Terminal strips on left/right sides for remote I/O link, I/O connections, and power.
- Two switch assemblies for rack number, communication rate, I/O group, last state, and chassis configuration.
Oiltech Controls’s Insight
- This module excels in legacy PLC systems where mixed I/O is required.
- Relay outputs handle AC loads up to 132V, suitable for motor starters and solenoids.
- Status LEDs simplify troubleshooting of communication and I/O states.
- Compact size reduces panel space, ideal for retrofit projects.
Typical Applications
- Remote I/O for PLC-5 and SLC 500 systems.
- Mixed discrete control in packaging and material handling.
- Relay output for AC valve actuators and alarm systems.
- Legacy system upgrades with minimal wiring changes.
Professional FAQ
Q1: Can this module replace a 1791-16BC in an existing PLC-5 rack?
A: Yes, but check I/O count and voltage compatibility. The 1791-24BR offers more inputs and relay outputs, so verify your program’s addressing.
Q2: What is the maximum switching frequency for the relay outputs?
A: The relays are rated for general-purpose AC loads. For high-frequency switching, consider solid-state outputs.
Q3: How do I set the starting I/O group on this module?
A: Use the two DIP switch assemblies. Refer to the manual for binary settings; common configurations are group 0, 1, or 2.
Q4: Is external power required for the inputs?
A: Yes, the module needs 19.2-30V DC external power for input circuits and logic.
Q5: What is the typical lifespan of the relay contacts?
A: Rated for 100,000 operations at full load; derate for inductive loads. Use external suppression for longer life.
Why Buy From Oiltech Controls?
- 15+ years supplying industrial automation spares globally.
- Worldwide shipping via FedEx, UPS, DHL.
- Every unit tested for functionality before dispatch.
- 12-month warranty against defects.
- Support for obsolete systems with expert technical verification.
- Refurbished options with new-component reliability.
Shipping & Warranty
- Dispatch: 24-28 hours after order confirmation.
- Carriers: FedEx, UPS, DHL – global express.
- Warranty: 12 months from invoice date.
For inquiries: info@oiltechcontrols.com or +86 158 8020 0923
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