Allen-Bradley 1746-NI16V SLC 500 Analog Input Module

1746-NI16V 16-Channel Voltage Input Module

Product Introduction

The Allen-Bradley 1746-NI16V is a high-density Analog Input Module designed for the SLC 500 programmable controller system. It accepts analog voltage signals from field devices such as transducers, sensors, and signal conditioners. This module features 16 input channels, each configurable for ±10V dc, 0 to 10V dc, 0 to 5V dc, or 1 to 5V dc. Therefore, it delivers precise measurement capabilities for process variables like pressure, temperature, flow, and position in industrial control applications.

Technical Specifications

The 1746-NI16V module offers exceptional flexibility with its 16 analog voltage input channels. Each channel supports four voltage ranges: ±10V dc, 0 to 10V dc, 0 to 5V dc, and 1 to 5V dc. The module provides 16-bit resolution, ensuring accurate and reliable signal conversion. Its conversion type is Sigma-Delta, which delivers high precision and excellent noise rejection. The input resolution is 312 mV.

The module draws a backplane current of 125 mA at 5 Volts DC and 75 mA at 24 Volts DC. Total backplane power consumption is 2.425 Watts maximum (0.625 Watts at 5V DC and 1.8 Watts at 24V DC). The thermal dissipation is 2.43 Watts. The input impedance is 20 kΩ, while the common mode voltage range is ±10.25 Volts relative to the analog common terminal. Furthermore, the module provides 500V AC isolation for 1 second, which enhances system safety and noise immunity.

For signal filtering, the 1746-NI16V includes a low-pass digital filter with programmable frequencies. You can select from 6 Hz, 10 Hz, 20 Hz, 40 Hz, 60 Hz, 80 Hz, 100 Hz, or 250 Hz. The bandwidth ranges from 6 to 250 Hertz, and the step response varies from 9 to 630 milliseconds depending on the selected filter frequency. The gain drift is 15 ppm/degree Celsius, and the input offset drift is 90 mV/degree Celsius.

Data Format and Configuration

The Allen-Bradley 1746-NI16V offers multiple user-selectable data formats to suit different control strategies. You can configure the module for Engineering Units, Scaled for PID, Proportional Counts with a -32,768 to +32,767 range, or Proportional Counts with a User-Defined Range (Class 3 only). This flexibility allows you to integrate the module seamlessly with various programming environments.

Additionally, the module communicates with the SLC 500 processor through a parallel rear-facing interface. It receives all necessary power from the SLC 500 power supply via the backplane.

Mechanical & Environmental Parameters

The 1746-NI16V performs reliably in a wide range of industrial environments. Its operating temperature range extends from -25 to +60 °C (-13 to +140 °F), while the storage temperature range is between -40 and +85 °C (-40 to +185 °F). The module operates effectively in conditions with 5 to 95% relative humidity without condensation.

This single-slot module fits into any SLC 500 chassis slot except Slot 0, which is reserved for the processor. The front panel includes 5 green status indicators: one for the module status and one for each group of 4 channels. These LEDs provide visual confirmation of module health and channel operation.

Installation and Wiring Guide

Installing the 1746-NI16V is a straightforward process. First, disconnect power from the SLC 500 chassis completely. Next, insert the module into any available slot except Slot 0. Slide it firmly into place until it seats fully against the backplane connector. Remember to disconnect power before removing or inserting this module, as electrical arcing can occur when a power source is connected.

For wiring, the module uses a 25-pin D-shell connector (AIFM connector). We recommend using Belden #8761 cable or an equivalent shielded cable for optimal signal integrity. The module has a replaceable terminal block with part number 1746-RT25G. You can also use pre-wired cables manufactured by Allen-Bradley in various lengths (0.5, 1.0, 2.5, and 5.0 meters). These cables pair with terminal blocks such as the 1492-AIFM8-3 and 1492-AIFM16-F-3. When using these pre-wired systems, manual wiring errors decrease significantly because the system provides proper color coding and easy-to-manage terminal block assemblies.

Applications

Voltage inputs like those on the Allen-Bradley 1746-NI16V interface with process variables to measure their magnitude. This module is primarily useful for monitoring applications or as a feedback signal for closed-loop control systems. By implementing control methods like the Proportional-Integral-Derivative (PID) algorithm, you can achieve manual or automatic control. Without this feedback signal, automatic control cannot function fully.

Certifications

The 1746-NI16V holds several important agency certifications. It is UL listed, C-UL approved, and CE compliant for all applicable directives. Additionally, the module is approved for use in Class I Division 2 Hazardous Environments, making it suitable for installations in potentially explosive atmospheres.

Packaging List

Your shipment of the Allen-Bradley 1746-NI16V will include the following item:

• (1) Allen-Bradley 1746-NI16V SLC 500 Analog Input Module

The module ships in protective anti-static packaging to ensure it arrives in perfect condition. A 25-pin D-shell connector and wiring tools are necessary for installation, but these items are not included with the module.

All orders ship promptly via FedEx, UPS, or DHL to guarantee fast and dependable delivery.

Frequently Asked Questions (FAQ)

1. What input signal types does the 1746-NI16V support?
The Allen-Bradley 1746-NI16V supports four voltage ranges: ±10V dc, 0 to 10V dc, 0 to 5V dc, and 1 to 5V dc. You can configure each channel individually for the appropriate signal type.

2. Can I install this module in Slot 0 of the SLC 500 chassis?
No, you cannot. The 1746-NI16V fits into any I/O module slot except Slot 0. The processor must occupy Slot 0 in the main chassis, so this module cannot go there.

3. What is the purpose of the programmable input filter?
The programmable filter reduces noise from the analog signal. You can select a filter frequency from 6 Hz to 250 Hz. A lower frequency provides more noise rejection but results in a slower step response. Choose the setting based on your specific application requirements.

4. What cable should I use for wiring the 1746-NI16V?
We recommend using Belden #8761 shielded cable or an equivalent shielded instrument cable. Shielded cable helps minimize electrical noise and ensures accurate signal transmission. You can also use pre-wired Allen-Bradley cables with terminal blocks like the 1492-AIFM8-3 for simplified installation.

5. Is the 1746-NI16V approved for use in hazardous locations?
Yes, it is. The Allen-Bradley 1746-NI16V is approved for use in Class I Division 2 Hazardous Environments. This certification makes it suitable for installations in areas where flammable gases or vapors may be present under abnormal conditions.