Product Overview

The Allen-Bradley 1746-NI4 is an analog input module for the SLC 500 system. This module provides four non-isolated differential input channels. Each channel is individually selectable for voltage or current input. The Allen-Bradley 1746-NI4 occupies a single slot in the SLC 500 chassis. Users trust this module for precise analog measurement in monitoring and control applications.

Technical Specifications

The 1746-NI4 delivers accurate analog conversion with flexible input configuration. Below are the complete technical details.

General Specifications

• Manufacturer: Rockwell Automation for industrial control reliability.

• Brand: Allen-Bradley for SLC 500 compatibility.

• Part Number: 1746-NI4 for precise identification.

• Series: SLC 500 programmable controller family.

• Module Type: Analog I/O Module (4-channel analog input).

• UPC: 10662073735905 for universal product identification.

• UNSPSC: 32151705 for classification.

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

• Compatibility: Fixed or modular style hardware.

Input Channel Specifications

• Number of Channels: Four (4) non-isolated differential inputs.

• Input Signal Category: -20 to +20 mA or -10 to +10V DC.

• Channel Configuration: User-selectable per channel via DIP switch.

• Input Type: Differential for noise rejection.

• Removable Terminal Block: Provides connections for each analog input.

Conversion Specifications

• Conversion Type: Delta-Sigma Modulation.

• Converter Resolution: 16 bit.

• Current Input Coding: -16,384 to +16,384.

• Voltage Input Coding: -32,768 to +32,767.

• Resolution (Current): 1.22070 µA per LSB.

• Resolution (Voltage): 305.176 µV per LSB.

• Update Time: 512 microseconds.

• Step Response: 60 milliseconds.

• Bandwidth: 10 Hertz.

• Repeatability: ±1 LSB.

• Non-linearity: 0.01%.

Current Input Specifications

• Input Range (Nominal): ±20 mA.

• Input Range (Maximum): ±30 mA.

• Input Impedance: 250 Ohms.

• Gain Error Drift: ±67 ppm/°C.

• Overall Accuracy at 25°C: ±0.365% of full scale.

• Overall Accuracy at 60°C: ±0.642% of full scale.

• Accuracy Drift: +79 ppm/°C of full scale.

Voltage Input Specifications

• Input Range: ±10 Volts DC -1 LSB.

• Input Impedance: 1 mega Ohm.

• Gain Error Drift: ±57 ppm/°C.

• Accuracy Drift: +63 ppm/°C of full scale.

• Overall Accuracy at 25°C: ±0.284% of full scale.

• Overall Accuracy at 60°C: ±0.504% of full scale.

Backplane Current Specifications

• Backplane Current (5 Volts): 25 milliamps (35 mA max listed).

• Backplane Current (24 Volts DC): 85 milliamps.

• Power Draw: Moderate for four-channel analog input.

Physical and Connection Specifications

• Cable Lengths: 0.5, 1, 2.5, or 5.0 meters standard.

• AIFM Connector: 15-pin D-shell.

• DIP Switches: On circuit board for input voltage or current selection.

• LED Indicators: Built-in for channel status and module operation.

• Diagnostic Interrupt: Controller's diagnostic interrupt for status access.

Important Usage Caution

• Do not connect voltage source to channel configured for current input.

• Incorrect configuration may cause module damage.

• Always verify DIP switch settings before applying signals.

Installation Guide

Follow these steps to install the Allen-Bradley 1746-NI4 correctly.

1. Power Down the Chassis: Turn off all power to the SLC 500 rack.

2. Locate an Available Slot: Find any I/O slot except slot 0.

3. Set DIP Switches: Configure each channel for voltage or current input.

4. Insert the Module: Slide the 1746-NI4 into the slot carefully.

5. Secure the Module: Lock using the retaining clips at top and bottom.

6. Wire Removable Terminal Block: Connect analog signals to the RTB.

7. Use Differential Wiring: Connect each channel as differential input.

8. Select Cable Length: Choose 0.5, 1, 2.5, or 5.0 meter cable.

9. Connect 15-Pin D-shell: Attach the AIFM connector if used.

10. Apply Power: Turn on the backplane power to the chassis.

11. Check LED Indicators: Verify status LEDs for proper operation.

12. Configure Scaling: Use scaling algorithm to display process variables.

13. Test Each Channel: Apply known signals and verify readings.

14. Monitor Accuracy: Check overall accuracy at ambient temperature.

Installation Notes

• Never connect voltage to a channel configured for current input.

• The module cannot go in slot 0 of the SLC 500 chassis.

• Delta-Sigma conversion provides 16-bit resolution.

• Update time is 512 microseconds per channel.

• LED indicators provide quick module diagnostics.

Packaging List

This unit ships as a new and original product.

• Allen-Bradley 1746-NI4 Analog I/O Module

• Removable terminal block (RTB)

• Product data sheet with DIP switch settings

• Anti-static factory packaging bag

Frequently Asked Questions (FAQ)

1. How many analog input channels does the 1746-NI4 provide?
The Allen-Bradley 1746-NI4 provides four non-isolated differential input channels. Each channel is individually selectable for voltage or current.

2. What input signal ranges does this module support?
The 1746-NI4 supports -20 to +20 mA for current input. For voltage input, it supports -10 to +10V DC.

3. What is the resolution of the 1746-NI4 analog module?
The Allen-Bradley 1746-NI4 has 16-bit resolution. Current input coding ranges from -16,384 to +16,384. Voltage input coding ranges from -32,768 to +32,767.

4. Can I install the 1746-NI4 in slot 0 of the SLC 500 chassis?
No, the 1746-NI4 cannot be installed in slot 0. It works in any other I/O module slot of the SLC 500 chassis.

5. What happens if I connect voltage to a current-configured channel?
Connecting voltage to a channel configured for current input may cause incorrect module operation or module damage. Always verify DIP switch settings before wiring.