1746-NI4 4-Channel Analog Input Module Allen-Bradley

1746-NI4 4-Channel Analog Input Module

Product Introduction

The Allen-Bradley 1746-NI4 is a compact and versatile Analog Input Module designed for the SLC 500 programmable controller system. It accepts analog signals from field devices such as transmitters, transducers, and sensors. This module features 4 differential input channels, and you can select each channel individually for voltage or current operation. Therefore, it delivers flexible measurement capabilities for process variables like pressure, temperature, flow, and level in industrial automation applications.

Technical Specifications

The 1746-NI4 module offers exceptional flexibility with its 4 differential analog input channels. Each channel supports either voltage or current input. For current, the range is -20 to +20 mA (nominal) with a maximum of ±30 mA. For voltage, the range is -10 to +10V dc. The module provides 16-bit resolution, ensuring accurate and reliable signal conversion. Its conversion type is Delta-Sigma Modulation, which delivers high precision and excellent noise rejection.

The module draws a backplane current of 25 mA at 5 Volts DC and 85 mA at 24 Volts DC. The update time is an impressive 512 microseconds, while the step response is 60 milliseconds. The bandwidth is 10 Hertz. The converter resolution is 16 bits, with repeatability of ±1 LSB and non-linearity of 0.01%.

For current input, the current coding range is -16,384 to +16,384. The input impedance is 250 Ohms, with a resolution of 1.22070 µA per LSB. The gain error drift is approximately ±67 ppm/degree Celsius. Overall accuracy at 25 °C is ±0.365% of full scale, and ±0.642% at 60 °C. The overall accuracy drift is +79 ppm/degree Celsius of full scale.

For voltage input, the voltage coding range is -32,768 to +32,767. The input impedance is 1 Mega Ohm, with a resolution of 305.176 µV per LSB. The gain error drift is ±57 ppm/degree Celsius. Overall accuracy at 25 °C is ±0.284% of full scale, and ±0.504% at 60 °C. The accuracy drift is +63 ppm/degree Celsius of full scale.

Configuration and Channel Selection

The Allen-Bradley 1746-NI4 allows you to configure each channel individually using DIP switches located on the circuit board. These switches select either voltage or current input for each channel. You must exercise caution when configuring these switches. Connecting a voltage source to a channel configured for current input can cause incorrect module operation or even module damage. Always verify your wiring matches the selected input type before applying power.

The module converts the analog input signal using Delta-Sigma Modulation. The converted data then undergoes processing with a scaling algorithm to display the measured process variable. Both voltage and current methods produce the same scaled output.

Mechanical & Environmental Parameters

The 1746-NI4 performs reliably in a wide range of industrial environments. Its operating temperature range extends from 0 to +60 °C (+32 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. Furthermore, the 1746-NI4 is compatible with both fixed and modular SLC 500 hardware styles. The fixed hardware version comes with embedded I/O channels and limited expansion capabilities, while the modular version offers a fully customizable system.

Installation and Wiring Guide

Installing the 1746-NI4 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.

For wiring, the module uses a 15-pin D-shell connector (AIFM connector). The module includes a removable terminal block that provides connections for each analog input channel. Each channel can connect as a differential input. We recommend using shielded cable for optimal signal integrity. Available standard cable lengths are 0.5, 1.0, 2.5, and 5.0 meters.

The module features built-in LED indicators for each channel and for the overall module status. These LEDs provide quick visual diagnostics. Additionally, you can access diagnostic information via the controller's diagnostic interrupt. This reporting system enables faster troubleshooting and increases module availability.

Packaging List

Your shipment of the Allen-Bradley 1746-NI4 will include the following item:

• (1) Allen-Bradley 1746-NI4 SLC 500 Analog Input Module

The module ships in protective anti-static packaging to ensure it arrives in perfect condition. A 15-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-NI4 support?
The Allen-Bradley 1746-NI4 supports both voltage and current inputs. You can select ±10V dc for voltage or ±20 mA for current. Each of the 4 channels is individually configurable using DIP switches on the circuit board.

2. Can I install this module in Slot 0 of the SLC 500 chassis?
No, you cannot. The 1746-NI4 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 happens if I connect a voltage source to a current-configured channel?
Connecting a voltage source to a channel configured for current input can cause incorrect module operation or damage the module. Always verify your DIP switch settings match your wiring before applying power to avoid this issue.

4. Is the 1746-NI4 compatible with fixed-style SLC 500 controllers?
Yes, it is. The Allen-Bradley 1746-NI4 works with both fixed and modular SLC 500 hardware styles. The fixed style has embedded I/O with limited expansion, while the modular style offers a fully customizable system.

5. How can I check the status of the module and its channels?
The 1746-NI4 includes LED indicators for each channel and for overall module status. These LEDs provide quick visual diagnostics. You can also access detailed diagnostic information through the controller's diagnostic interrupt for faster troubleshooting.