1791-32B0 Allen-Bradley 32-Point DC Input Block IO Module

Product Overview – 1791-32B0 Block IO

1791-32B0 is a 32-channel DC input module from Allen‑Bradley. It belongs to the 1791 Block I/O series. This module operates at 24V DC nominal (10‑30V range). It provides 32 inputs arranged as 4 isolated groups (8 per group). The design supports DIN‑rail mounting for compact cabinets.

Core Technical Data

• Brand: Allen‑Bradley / Rockwell Automation
• Model: 1791‑32B0
• Series: 1791 Block I/O
• Inputs: 32 points (sinking/sourcing)
• On‑state voltage: 10‑30V DC (24V nom)
• On‑state current: 2.5mA @10V to 11mA @30V
• Off‑state voltage: 5V DC max
• Off‑state current: 1.5mA min
• Input impedance: 3.4 kΩ max
• External power: 19.2‑30V DC, 300mA
• Isolation: 500V AC (power to I/O, group‑to‑group)
• Power dissipation: 16.3W max
• Thermal dissipation: 55.6 BTU/hr
• Dimensions: 6.95 x 4.35 x 3.85 in
• Weight: 1.81 lbs (0.82 kg)

Installation & Wiring Essentials

• Mount on 35mm DIN rail (standard clip).
• Use Belden 9463 for remote I/O link.
• I/O wiring: 14 AWG stranded, 3/64″ insulation.
• Terminal strips on left/right for inputs and power.
• Set rack number and baud rate via DIP switches.
• Observe polarity for external power (19.2‑30V DC).

Debug, Maintenance & Diagnostics

• Status LEDs for each input and communication.
• Monitor I/O state via LED indicators.
• Check off‑state leakage to avoid false triggers.
• No calibration required; plug‑and‑play.
• Use last‑state or reset switch for fault recovery.

Compatibility & Target Systems

• PLC‑2, PLC‑3, PLC‑5/250, PLC‑5 controllers.
• SLC 5/02 modular controllers.
• Works with 1771 series output modules (check leakage).
• Compatible with 100‑A45 contactors, Type F/P/PH relays.
• Use with DC sinking/sourcing devices in on‑state region.

Certifications & Compliance

• UL Listed (File E199301).
• CE Marked for EMC.
• RoHS Compliant.
• Remote I/O conformance tested.

Package Contents

• 1 x 1791‑32B0 Block I/O module.
• Removable terminal strips (left & right).
• DIN‑rail mounting clip (attached).
• Quick start guide (English).
• No cables or power supply included.

Warranty, Shipping & Delivery

• 12‑month warranty against defects.
• Ship within 24‑28 hours via FedEx, UPS, or DHL.
• Tracking number provided after dispatch.

Oiltech Controls’s Insight

• This 1791‑32B0 is a workhorse for discrete input monitoring.
• Ideal for retrofit or expansion of legacy PLC systems.
• We recommend checking off‑state current of connected outputs.
• Use shielded cable for noisy environments.
• Test group‑to‑group isolation if mixing voltages.

Oiltech Controls Review

• “Reliable 32‑point input block with clear LED status.”
• “Easy DIN‑rail mount and screw terminals.”
• “Works seamlessly with our PLC‑5 upgrade.”
• “Good thermal performance at 16.3W.”
• “Fast shipping and well‑packed.”

Expert FAQ & Selection Guide

Q1: Can I use this module with 1771 output modules?
Yes, if the output’s off‑state leakage is below 1.5mA and its on‑state drop keeps voltage above 10V DC at the input.

Q2: What happens if input voltage exceeds 30V?
Permanent damage may occur. Always keep within 10‑30V DC range.

Q3: How do I set the I/O rack number?
Use the two DIP switch assemblies on the module. Refer to the manual for binary settings.

Q4: Which controllers are directly compatible?
PLC‑2, PLC‑3, PLC‑5/250, PLC‑5, and SLC 5/02. For other brands, use remote I/O adapter.

Q5: What is the recommended wire type?
Belden 9463 for remote I/O link; 14 AWG stranded with 3/64″ insulation for field wiring.

Why Buy From Oiltech Controls?

• Decade‑plus expertise in industrial automation spares.
• Worldwide shipping with live tracking.
• Tested surplus and refurbished units available.
• Full 12‑month warranty on every purchase.
• Every module verified technically before dispatch.
• Specialist support for obsolete control systems.

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