Allen‑Bradley 1790D-T32BV0 Universal Input Module

Allen‑Bradley 1790D-T32BV0 32 Universal Input Base Module

Product Introduction

The 1790D-T32BV0 from Allen‑Bradley delivers 32 digital input channels in a compact DeviceNet base module. Each input accepts both sinking and sourcing wiring configurations. This non‑polarity design simplifies field wiring and reduces installation errors.

Furthermore, this module operates at 24V dc nominal with a wide voltage range of 9.6V dc (minimum on‑state) to 28.8V dc (maximum). The on‑state current reaches up to 8 mA per channel at 28.8V dc. Meanwhile, the off‑state voltage threshold is 5.0V dc maximum, ensuring clear signal discrimination.

Therefore, the 1790D-T32BV0 suits applications with many digital field devices. For instance, you can connect limit switches, proximity sensors, or pushbutton panels. Additionally, the 32 green status LEDs provide immediate visual feedback for each channel.

Technical Specifications (Input Characteristics)

• Inputs per module: 32 points, sinking or sourcing (non‑polarity)

• On‑state voltage range: 9.6V dc min, 24V dc nom, 28.8V dc max

• Off‑state voltage (max): 5.0V dc

• On‑state current (max): 8 mA per channel at 28.8V dc

• Input impedance (nominal): 4.8 KΩ (key parameter)

• Indicators: 32 green input status LEDs (one per channel)

• Common type: 16 points / 4COM (non‑polarity)

The non‑polarity common design means you do not need to worry about sinking vs. sourcing compatibility. Simply connect your field device across the input terminal and any common terminal within the same group. This feature saves engineering time and reduces spare parts inventory.

General & Power Specifications

• DeviceNet supply voltage: 24V dc nominal (range 11‑28.8V dc)

• DeviceNet power dissipation: 1.2W max at 28.8V dc

• Isolation:

  • I/O to logic: photocoupler isolation, 1250V ac rms (key parameter)

  • DeviceNet to logic: non‑isolated

  • DeviceNet power: non‑isolated

• Wiring terminal block: M3.0 screw type, torque 7 lb‑in max (use copper or copper‑clad aluminum conductors)

The photocoupler isolation protects the logic side from field wiring transients. However, note that the DeviceNet communication and power circuits share a common reference. Therefore, you must ensure proper grounding practices in your control panel.

Mechanical & Environmental Information

The 1790D-T32BV0 mounts on a standard DIN rail or panel. It operates reliably from 0°C to 55°C ambient temperature. Storage range extends from -40°C to 85°C. Humidity tolerance is 5‑95% non‑condensing.

Additionally, this base module does not require external cooling under normal conditions. The low power dissipation of 1.2W keeps heat generation minimal. Because the input impedance is 4.8KΩ, you can connect most 24V dc sensors without additional current limiting resistors.

Installation Guidelines

First, disconnect both DeviceNet power and any external field supply. Next, mount the 1790D-T32BV0 on a DIN rail or use panel mounting screws.

For wiring, use copper conductors sized 0.5‑1.5 mm² (20‑16 AWG). Tighten each M3 screw to 7 lb‑in maximum. The terminal block is clearly marked with input numbers and common groups.

Each common group supports up to 16 inputs (4COM total for 32 points). Because the commons are non‑polarity, you can connect either the positive or negative side of your 24V dc supply to any common terminal. Then connect the sensor output to the corresponding input terminal.

Finally, connect the DeviceNet cable to the module's pass‑through connectors. Apply power and verify the green LEDs light correctly when inputs are activated.

Packaging List (Per Unit)

• 1790D-T32BV0 32 Universal Input Base Module – 1 pc

• Terminal block (pre‑attached) – 1 pc

• Quick start guide (printed) – 1 pc

• Dust cover – 1 pc

Note: No certificates or warranty documents are included in the package.

Shipping & Delivery

We ship worldwide via FedEx, UPS, or DHL. All modules are packed in anti‑static and anti‑shock materials. Tracking number will be provided within 24 hours after dispatch.

Frequently Asked Questions (FAQ)

1. Can I mix sinking and sourcing sensors on the same 1790D-T32BV0 module?
Yes. The non‑polarity input design accepts both types without any configuration changes. Simply connect the sensor output to the input terminal, and the common to either positive or negative supply rail.

2. What happens if I apply 30V dc to an input?
The absolute maximum rating is 28.8V dc. Exceeding this may damage the input circuit. Always stay within the specified 9.6‑28.8V dc range.

3. How many inputs share one common terminal?
Each common group serves 16 inputs. The 1790D-T32BV0 has 4 commons for 32 total points. This grouping allows flexible power distribution across different voltage zones.

4. Is the 1790D-T32BV0 compatible with older 1790 series bases?
Yes, it shares the same mechanical footprint and DeviceNet interface. However, always check the input count and common arrangement to match your existing wiring layout.

5. Why do my input LEDs stay on even when no sensor is connected?
This indicates a wiring issue or a floating input. Verify that each unused input is either left open (reads off) or pulled to the off state below 5V dc. A loose common wire can also cause false on readings.