Product Overview

The 1790D-N0C2 is a 2-channel analog current output module from Allen-Bradley, designed for precise control in industrial automation systems. This compact module integrates seamlessly with DeviceNet networks, offering reliable 0…20 mA output signals for actuators, valves, and other field devices. Its nonisolated, single-ended design ensures straightforward installation and cost-effective performance in demanding environments.

Technical Specifications Analysis

The 1790D-N0C2 delivers two channels of analog current output with a range of 0…20 mA. It features 12-bit resolution, providing 1/4096 max scale steps and a fine 4.88 µA/bit granularity. Conversion time is 2 ms per channel, enabling responsive control loops. Overall accuracy is 0.2% full scale across 0…55 °C, and no calibration is required. The module accepts DeviceNet power at 24V dc nominal (11…28.8V dc range) with a maximum dissipation of 1.2 W. Field power requires 24V dc nominal (21.6…26.4V dc) and dissipates up to 1.5 W. Isolation between I/O and logic is provided via photocoupler, tested at 1250V ac rms for 60 s. The module uses a 37-pin D-shell connector and includes two red/green I/O status indicators.

Application Scenarios & Usage Methods

In process control, the 1790D-N0C2 drives proportional valves or variable frequency drives requiring 0…20 mA signals. For example, connect the module to a flow control valve to regulate chemical dosing in a petrochemical plant. In manufacturing, use it to command servo drives or positioners in assembly lines. The 2 ms conversion time supports fast updates, while the 600 Ω maximum external load resistance ensures compatibility with most actuators. Always verify field power polarity and load resistance before commissioning.

Installation Guide & Packing List

Mount the 1790D-N0C2 on a DIN rail in a clean, dry enclosure. Connect DeviceNet power via the bus connector and field power through the terminal block. Wire analog outputs to the 37-pin D-shell connector using shielded cable to reduce noise. Ensure the total external load does not exceed 600 Ω. The package includes the analog base module and a 37-pin D-shell connector. Expansion modules (up to two discrete modules) are sold separately.

Purchasing Advice

When selecting the 1790D-N0C2, confirm your system requires 0…20 mA output and DeviceNet communication. This module suits applications needing high accuracy (0.2%) and fast conversion (2 ms). For reliable supply, choose PetroPartsOnline, a trusted distributor of industrial automation and oil/gas parts. Verify compatibility with your existing Allen-Bradley system before ordering.

Repair & Maintenance Tips

Periodically inspect the 37-pin connector for corrosion or loose wires. Keep the module free of dust and moisture; use compressed air for cleaning. Store in a static-safe environment between 0…55 °C. No calibration is needed, but verify output accuracy annually with a precision meter. Replace the module if status indicators show persistent faults.

Frequently Asked Questions (FAQs)

Q: What is the output range of the 1790D-N0C2?

A: The module provides 0…20 mA analog current output per channel.

Q: What is the resolution of this module?

A: It has 12-bit resolution, equivalent to 1/4096 max scale steps or 4.88 µA per bit.

Q: Does the 1790D-N0C2 require calibration?

A: No, calibration is not required. The module maintains 0.2% full scale accuracy over 0…55 °C.

Q: What is the maximum load resistance for the output?

A: The allowable external output load resistance is 600 Ω maximum.

Q: How many expansion modules can I add?

A: This analog base module can accommodate a maximum of two discrete expansion modules.