Product Summary
The 1746-NI4 is a high-performance analog input module for the SLC 500 system. It provides four non-isolated differential channels. You can select voltage or current inputs for each channel. This module delivers 16-bit resolution for precise data conversion. It fits any I/O slot except slot zero.
Expert Technical Evaluation & Performance Review
This module uses Delta-Sigma modulation for analog-to-digital conversion. This technique provides excellent noise rejection and linearity. The 1746-NI4 achieves a non-linearity of just 0.01%. This ensures your process data remains accurate and reliable.
The module offers a fast update time of 512 microseconds. This speed allows for responsive control loops. The bandwidth is 10 Hertz, which filters high-frequency noise effectively. The step response time is 60 milliseconds for stable readings.
For voltage inputs, the coding range is -32,768 to +32,767. This corresponds to a resolution of 305.176 microvolts per LSB. The input impedance is 1 megaohm, which minimizes signal loading. The overall accuracy at 25 degrees Celsius is ±0.284% of full scale.
For current inputs, the coding range is -16,384 to +16,384. The resolution is 1.22070 microamps per LSB. The input impedance is 250 ohms, suitable for standard loops. The accuracy at 25 degrees Celsius is ±0.365% of full scale.
The module demonstrates strong thermal stability. The gain error drift for voltage is ±57 ppm per degree Celsius. The accuracy drift is +63 ppm per degree Celsius of full scale. For current, the gain error drift is ±67 ppm per degree Celsius.
The repeatability is ±1 LSB, which guarantees consistent measurements. This performance is critical for applications like temperature control. It also works well for pressure monitoring and flow measurement. The module handles signals from -10 to +10V DC or -20 to +20 mA.
You must use the DIP switches on the circuit board. These switches select the input type for each channel. Do not connect a voltage source to a current-configured channel. This action can cause incorrect operation or damage.
Maintenance, Troubleshooting & Longevity Protocols
Proactive maintenance ensures long-term reliability for your 1746-NI4 module. You should inspect the module during scheduled plant shutdowns. Check the LED indicators for each channel and the module status. A solid green light indicates normal operation.
You must inspect the removable terminal block for corrosion. Look for signs of loose wiring or physical damage. Clean the module contacts with a dry, lint-free cloth. Do not use solvents or abrasive cleaners.
The module draws 25 milliamps from the 5-volt backplane. It draws 85 milliamps from the 24-volt backplane. Verify your power supply can handle this load. An overloaded backplane can cause erratic module behavior.
Standard cable lengths are 0.5, 1.0, 2.5, or 5.0 meters. Use only shielded cables for analog signals. Ensure the shield is grounded at one end only. This prevents ground loops and reduces electrical noise.
You should verify the input signal range during troubleshooting. Use a calibrated multimeter to check the signal at the terminal block. Compare this reading to the scaled value in your control program. A large discrepancy indicates a wiring or configuration issue.
If you get erratic readings, check the chassis location. The module can go in any slot except slot zero. Slot zero is reserved for the processor. A faulty backplane connection can also cause issues. Reseat the module to ensure a good connection.
Logistics & Standard Packaging Details
- One (1) Allen-Bradley 1746-NI4 SLC 500 Analog Input Module
- One (1) Removable Terminal Block
- One (1) Quick Start Guide
We ship all orders via express delivery services. You can choose FedEx, UPS, or DHL for your shipment. This ensures fast and reliable delivery to your facility.
