Allen-Bradley 1790D-N0C2 2-Channel Analog Current Output Module
Product Introduction
The 1790D-N0C2 from Allen‑Bradley is a reliable analog output solution for industrial automation. This module provides two single‑ended, nonisolated current outputs. It operates within a 0…20 mA range and uses 12‑bit resolution. Each bit equals 4.88 µA, giving you fine control over your analog signals.
Additionally, the device supports binary data conversion from 0000 to 0fff (max scale). Its conversion time reaches only 2ms per channel, ensuring fast system response. Overall accuracy stays within 0.2% full scale at 0…55 °C. You will not need any field calibration, which simplifies maintenance.
Technical Specifications
The 1790D-N0C2 works with an allowable external load resistance up to 600 Ω maximum. Insulation resistance between insulated circuits is 20 mΩ minimum at 250V dc. The module uses photocoupler isolation between I/O and logic, with a type test of 1250V ac rms for 60 seconds.
For power requirements, the DeviceNet supply accepts 11…28.8V dc (24V dc nominal) and draws up to 1.2 W at 28.8V dc. The field power supply needs 21.6…26.4V dc (24V dc nominal, +10%) and consumes 1.5 W max at 26.4V dc. Two red/green I/O status indicators help you monitor operation easily.
Mechanical and Environmental Data
This base module connects via a 37‑pin D‑shell connector. It can host up to two discrete expansion modules. The operating temperature range suits 0…55°C. Because it is nonisolated between DeviceNet and logic as well as field power, proper grounding is important.
Installation Guidelines
First, mount the 1790D-N0C2 securely in a suitable enclosure. Then connect the DeviceNet cable to the network connector. Next, wire your field devices to the 37‑pin D‑shell following the pinout diagram. Ensure the load resistance does not exceed 600 Ω per channel. Finally, apply field power (24V dc nominal) and DeviceNet power separately.
Meanwhile, do not exceed the maximum voltage ranges. Use shielded cables where possible to reduce noise. The module requires no calibration after installation, which saves time.
Packaging List
1 x 1790D-N0C2 Analog Current Output Module
1 x 37‑pin D‑shell connector (mating)
Quick start guide (printed)
Note: Certificates and warranty are not included in the package.
Shipping Methods
We ship worldwide via FedEx, UPS, or DHL.
Frequently Asked Questions (FAQ)
1. Does the 1790D-N0C2 need external calibration?
No. The module requires no calibration at all. Its accuracy remains within 0.2% full scale over 0…55°C.
2. Can I add expansion modules to this analog base?
Yes. This base module supports up to two discrete expansion modules. Use them to increase your I/O count.
3. What happens if the load resistance exceeds 600 Ω?
The output current may drop or become unstable. Always keep the external load resistance at or below 600 Ω per channel.
4. Is the 1790D-N0C2 isolated from the DeviceNet network?
No. DeviceNet to logic is nonisolated. Also, field power is nonisolated. However, I/O to logic uses photocoupler isolation.
5. What resolution does the 1790D-N0C2 provide?
It provides 12‑bit resolution. That equals 1/4096 of scale, or 4.88 µA per bit. Binary data ranges from 0000 to 0fff.
