1791-NDV Allen-Bradley Analog Block I/O Module
Product Introduction
The Allen-Bradley 1791-NDV module delivers precise analog control for industrial applications. You get 4 analog inputs and 2 voltage outputs in a single block. This device requires a 24V DC power supply drawing only 600 mA.
Furthermore, it communicates smoothly with PLC-2, PLC-3, PLC-5/250, PLC-5, and SLC5/02 controllers. Many technicians prefer the 1791-NDV for its voltage output capability. For instance, you can use it to drive actuators or analog valves directly. Therefore, this module reduces the need for extra signal converters.
Technical Specifications
The 1791-NDV offers excellent input accuracy. Input resolution reaches 14 bits full scale. The update rate per channel is 108 ms. Input impedance measures 10 megaohms for voltage and 250 ohms for current. Absolute input accuracy stays at 0.1% at 25°C, while linearity reaches 0.05% at 25°C.
Meanwhile, the two voltage outputs provide a clean signal. Output impedance is less than 1 ohm. Short circuit protection is indefinite. The output follows the input signal reliably.
Power dissipation maxes at 11.52 W. Thermal dissipation reaches 39.28 BTU/hr. The input bandwidth is fixed at 5 Hz. Overvoltage protection handles up to 140V AC on both inputs and outputs.
Additionally, pay attention to the 249-ohm input current shunt. It is rated at 0.25 Watts. Never exceed this rating to avoid damage.
Environmental and Mechanical Data
The 1791-NDV module measures 6.95 x 2.7 x 3.85 inches (H x W x D). It weighs 1.19 lbs.
Operating temperature ranges from 0 to 60°C. Storage temperature spans -40 to 85°C. Relative humidity tolerance is 5 to 95% non-condensing. Therefore, this module suits most factory environments.
Installation Guidelines
First, disconnect all power before handling the 1791-NDV. Next, mount the block on a DIN rail or panel using the built-in clips. Then, connect the 19.2 to 30V DC supply to the power terminals. After that, wire analog inputs using twisted shielded cables. Finally, connect voltage outputs to your load devices.
Moreover, always verify environmental conditions before startup. Ensure temperature stays within 0 to 60°C. Keep humidity below 95% non-condensing. These steps guarantee reliable long-term operation.
Packaging List
Allen-Bradley 1791-NDV Analog Block I/O Module – 1 unit
Terminal block (pre-attached)
Quick reference wiring guide
Shipping via FedEx, UPS, or DHL.
Frequently Asked Questions (FAQ)
1. Which controllers work with the 1791-NDV?
The 1791-NDV is compatible with PLC-2, PLC-3, PLC-5/250, PLC-5, and SLC5/02 controllers.
2. What is the difference between 1791-NDC and 1791-NDV?
The 1791-NDC provides current outputs (0-20 mA), while the 1791-NDV delivers voltage outputs with less than 1 ohm impedance.
3. Can I exceed the 0.25W rating on the current shunt?
No. The 249-ohm shunt on the 1791-NDV is rated at 0.25W maximum. Exceeding this may permanently damage the module.
4. How fast does the 1791-NDV update outputs?
Each input channel updates every 108 ms. Outputs respond immediately to the corresponding input signals.
5. What happens if the temperature exceeds 60°C?
Operation above 60°C may cause accuracy drift or component failure. Always keep the 1791-NDV within its specified 0 to 60°C ambient range.
