Allen-Bradley 1790D-8BV8B 8 Input 8 Output Module 24V

Allen-Bradley 1790D-8BV8B 16-Point I/O Module

Product Introduction

The Allen-Bradley 1790D-8BV8B belongs to the CompactBlock LDX family. This module serves as a base or expansion unit. It gives you 8 universal input points. You also get 8 sourcing output points. The module operates on a 24V DC nominal supply. Inputs accept both sinking and sourcing field devices. Outputs provide 0.5A per channel maximum. Additionally, the 1790D-8BV8B supports DeviceNet communication. Photocoupler isolation protects the logic side from field noise.

Key Input Specifications for 1790D-8BV8B

The 1790D-8BV8B offers 8 nonisolated input points. Each point works as sinking or sourcing. The on-state voltage ranges from 9.6V DC minimum to 28.8V DC maximum. Nominal voltage is 24V DC. On-state current reaches 8 mA maximum per point at 28.8V DC. Off-state voltage stays at 5V DC maximum. Input impedance is 4.8 kOhms nominal. Eight green status indicators show input activity. The common type is 8 points sharing 8COM. This configuration has no polarity requirement.

Key Output Specifications for 1790D-8BV8B

This module provides 8 nonisolated sourcing outputs. The on-state voltage ranges from 10V DC minimum to 28.8V DC maximum. Nominal voltage is 24V DC. Maximum voltage drop is 0.5V DC. Minimum on-state current per channel is 1 mA. Off-state leakage stays below 0.5 mA. Output signal delay is 0.5 ms maximum for off-to-on. On-to-off delay reaches 1.0 ms maximum. Eight green status indicators show output status. Each output handles 0.5A maximum. The common rating is 4.0A maximum per 8COM.

General Specifications and Power Requirements

The 1790D-8BV8B draws its logic power from DeviceNet. The nominal supply voltage is 24V DC. Operating range goes from 11V to 28.8V DC. Maximum power dissipation is 1.2W at 28.8V DC. Field power also requires 24V DC nominal. Its range covers 10V to 28.8V DC. Field power dissipation is 6 mA per point at 28.8V DC.

For isolation, the module uses photocouplers. Isolation exists between I/O and logic. The isolation voltage rating is 1250V AC rms. However, DeviceNet to logic is nonisolated. DeviceNet power is also nonisolated. Keep this in mind when designing your system. Wiring connects through a 37-pin D-shell connector.

Mechanical and Environmental Ratings

The 1790D-8BV8B has a compact footprint. It mounts directly on a DIN rail. Operating temperature ranges from 0°C to 55°C. Storage temperature goes from -40°C to 85°C. Relative humidity stays between 5% and 95% non-condensing. Vibration resistance is 5g from 10 to 500Hz. Shock resistance is 30g for 11 milliseconds. The enclosure has an open type rating. You must install it inside a control cabinet.

Installation and Wiring Guidelines

Mount the 1790D-8BV8B on a standard 35mm DIN rail. Ensure proper orientation with terminals facing outward. Use a 37-pin D-shell cable for field wiring. We recommend pre-assembled cables from Rockwell. Strip wires to 6mm length for terminal blocks. Tighten screws to 0.5 Nm torque. Connect 24V DC field power to the designated terminals. Ground the DeviceNet cable shield at one point only. Do not run high voltage wires near the module. Maintain at least 50mm separation from power cables.

The module automatically detects input type. You do not need jumpers for sinking or sourcing configuration. Outputs are sourcing only. Therefore, your loads must connect between output and DC common.

Packaging List

• Allen-Bradley 1790D-8BV8B CompactBlock LDX module (1 unit)

• Built-in DeviceNet communication interface

• 37-pin D-shell female connector (attached to module)

• DIN rail mounting clip (pre-installed)

• Quick start installation sheet

*Note: DeviceNet cables, 37-pin D-shell mating connectors, and power supplies are sold separately.*

Shipping Information

We ship all I/O modules within 24 hours. Your 1790D-8BV8B will travel via FedEx, UPS, or DHL. Each package includes foam padding for shock protection. Tracking information is sent to your email address. Delivery typically takes 3-7 business days worldwide.

Frequently Asked Questions (FAQ)

1. Can the 1790D-8BV8B accept both AC and DC inputs?
No. This module accepts only 24V DC inputs. The input range is 9.6V to 28.8V DC. AC signals will damage the module.

2. What is the maximum current per common on the 1790D-8BV8B outputs?
Each output handles 0.5A maximum. The total per common (8COM) is 4.0A maximum. Exceeding this will damage the internal PCB traces.

3. Does the 1790D-8BV8B require external DeviceNet power?
Yes. The module draws its logic power from the DeviceNet network. You must provide 24V DC DeviceNet power to the bus. Field power for outputs is separate.

4. How do I connect field devices to the 1790D-8BV8B?
You need a mating 37-pin D-shell connector (sold separately). Rockwell offers pre-made cables or bare connectors. Wire your sensors and actuators to that connector.

5. Is the 1790D-8BV8B compatible with other DeviceNet masters?
Yes. This module follows standard DeviceNet protocol. It works with any Class 2 DeviceNet scanner. Examples include 1756-DNB or 1769-SDN.