Product Overview

The Allen-Bradley 1746-NI16I is an analog input module. It belongs to the SLC 500 product family. This module features sixteen (16) inputs configurable for multiple current ranges.

Supported input types include 0 to 20 mA, 4 to 20 mA, ±20 mA, and 0 to 1 mA. Furthermore, the module offers 16-bit resolution and a Sigma-Delta conversion type. Therefore, it suits high-precision analog measurement applications.

General Specifications

The 1746-NI16I offers high-density analog input capability for SLC 500 systems.

• Manufacturer: Rockwell Automation.

• Brand: Allen-Bradley.

• Series: SLC 500.

• Part Number/Catalog No.: 1746-NI16I.

• Module Type: Analog Input Module.

• Number of Inputs: Sixteen (16).

• Chassis Location: Any I/O module slot except slot 0.

• UPC: 10611320228196.

Electrical Specifications

The 1746-NI16I accepts multiple current signal types.

• Electrical Signal Types: 0 to 20 mA, 4 to 20 mA, ±20 mA, and 0 to 1 mA.

• Input Impedance: 249 Ω.

• Maximum Voltage Input: ±8 Volts (between analog common and any input terminal).

• Maximum Current Input: ±30 mA.

• Common Mode Voltage Range: ±10.25 Volts (relative to analog common terminal).

• Isolation: 500V AC for 1 second.

• Conversion Type: Sigma-Delta.

• Resolution: 16-bit.

Backplane Power Consumption

The 1746-NI16I draws moderate power from both backplane voltages.

• Backplane Current (5 Volts): 125 milliamps.

• Backplane Current (24 Volts DC): 75 milliamps.

• Backplane Power Consumption: 2.425 Watts maximum.

  • 0.625 Watts at 5 Volts DC.

  • 1.8 Watts at 24 Volts DC.

• Thermal Dissipation: 2.43 Watts.

Input Filtering

The 1746-NI16I includes programmable low-pass digital filters.

• Filter Type: Low-pass digital filter.

• Programmable Filter Frequencies: 6 Hz, 10 Hz, 20 Hz, 40 Hz, 60 Hz, 80 Hz, 100 Hz, 250 Hz.

• Bandwidth: 6-250 Hertz.

• Step Response: 9 to 630 milliseconds (depending on filter selection).

Therefore, the module can be optimized for noise rejection or fast response as required.

Data Formats

The 1746-NI16I supports multiple user-selectable data formats.

• Engineering Units.

• Scaled for PID.

• Proportional Counts (-32,768 to +32,767 range).

• Proportional Counts with User-Defined Range (Class 3 only).

Consequently, the module integrates easily with different control system requirements.

Open Circuit Detection

The 1746-NI16I features the capability of detecting an open circuit on any input channel. For this reason, the module can alert the PLC to wiring failures or sensor faults.

LED Indicators

The 1746-NI16I provides clear visual status indication.

• Number of LEDs: 5 green status indicators.

• Group Indicators: One LED for each group of 4 channels (4 LEDs total).

• Module Status: One LED for overall module status.

Hence, operators can quickly identify module health and channel activity.

Connector and Wiring

The 1746-NI16I uses a standard connector for field wiring.

• Connector Type: 25-pin D-shell (AIFM connector).

• Recommended Cable: Belden #8761 or equivalent.

• Maximum Wire Size: 14 AWG.

• Wires per Terminal: Up to 2 wires.

• Note: Use recommended wiring practices to avoid cluttering and difficulty closing the module door.

Environmental Specifications

The 1746-NI16I withstands a wide range of industrial conditions.

• Operating Temperature: -25 to 60°C (-13 to 140°F).

• Non-operating (Storage) Temperature: -40 to 85°C (-40 to 185°F).

• Relative Humidity: 5% to 95% (non-condensing).

Installation Guidelines

Install the 1746-NI16I in any I/O module slot of an SLC 500 chassis except slot 0. First, ensure the chassis power supply can provide the required 125 mA at 5V and 75 mA at 24V. Then, insert the module into the slot.

When installing the module, it is not necessary to remove the terminal blocks. However, if the terminal block is removed, use the label located next to it to identify the location and type of module.

Wire analog inputs using recommended Belden #8761 or equivalent cable. Terminate up to two 14 AWG wires per terminal. Configure each input channel for the desired current range (0-20mA, 4-20mA, ±20mA, or 0-1mA).

Select the appropriate filter frequency from 6 Hz to 250 Hz. Choose the desired data format (Engineering Units, Scaled for PID, or Proportional Counts). The module will detect open-circuit conditions on input channels.

Typical Applications

The 1746-NI16I suits various analog input monitoring applications.

• Process variable monitoring (pressure, flow, level, temperature) using 4-20mA transmitters.

• Closed-loop PID control feedback signals.

• Combination 120V AC I/O systems requiring analog inputs.

• High-channel-count analog monitoring in SLC 500 systems.

• Retrofit upgrades to existing SLC 500 installations.

What is in the Box

Please inspect all items upon delivery.

• Allen-Bradley 1746-NI16I analog input module.

• 25-pin D-shell connector (on module).

• Installation instruction manual.

Frequently Asked Questions (FAQ)

1. How many analog input channels does the 1746-NI16I have?

The 1746-NI16I provides sixteen (16) analog input channels. All channels are configurable for different current ranges.

2. What input signal types does this module accept?

The 1746-NI16I accepts 0 to 20 mA, 4 to 20 mA, ±20 mA, and 0 to 1 mA signals. Therefore, it suits most industrial current loop transmitters.

3. What is the resolution of this analog input module?

The 1746-NI16I has 16-bit resolution. It uses a Sigma-Delta conversion type for high accuracy.

4. Can this module be installed in slot 0 of an SLC 500 chassis?

No. The 1746-NI16I can be installed in any I/O module slot except slot 0. Slot 0 is typically reserved for the CPU or power supply.

5. What filter frequencies are available on this module?

The 1746-NI16I offers programmable filter frequencies: 6 Hz, 10 Hz, 20 Hz, 40 Hz, 60 Hz, 80 Hz, 100 Hz, and 250 Hz. Consequently, the user can balance noise rejection against response time.