1746-NIO4V | Allen-Bradley SLC 500 Analog Combination Module

The module supports two differential analog inputs, which can be configured individually for either voltage or current. The voltage input range is -10 to +10 VDC with a resolution of 305.176 µV per LSB, while the current input range is -20 to +20 mA with a resolution of 1.2207 µA per LSB. This allows precise analog signal measurement for process control and monitoring applications. The inputs use Delta-Sigma modulation, offering high linearity and repeatability. Each input channel is designed for high-accuracy acquisition with overvoltage protection.

The input channels offer field wiring-to-backplane isolation of 500 VDC, providing electrical protection to the controller and improving noise immunity. However, the output channels are non-isolated, meaning caution must be taken when grounding and wiring outputs to avoid interference or ground loops. Proper shielding and wiring practices are essential when using non-isolated outputs. The isolation on the input side ensures safer signal acquisition from external analog devices. It allows the module to operate reliably even in electrically noisy environments.

Yes, the 1746-NIO4V can be integrated into CompactLogix and ControlLogix systems when used as part of a distributed I/O setup via communication adapters. While it is not directly installed in these newer platforms, it can still function within hybrid architectures. This allows users to continue leveraging SLC 500 I/O modules while transitioning to modern PAC systems. It ensures investment protection for existing equipment while enhancing overall system capabilities. Communication bridging is typically required for full integration.

The analog inputs offer a 16-bit resolution, while the outputs provide 14-bit resolution. The input voltage resolution is 305.176 µV per LSB, and current resolution is 1.2207 µA per LSB, allowing for very fine measurements. Input accuracy is rated at ±0.642% with drift characteristics of 79 ppm per 5°C, while output accuracy is ±0.384% of full scale. These specifications ensure that the module can deliver reliable and consistent analog data acquisition and control. It is well-suited for applications that require high precision over a wide temperature range.

No, the 1746-NIO4V has been discontinued by Rockwell Automation along with the SLC 500 series. While it is no longer in active production, it remains widely used in legacy systems and is still available through aftermarket and surplus channels. Rockwell Automation provides migration guidance toward CompactLogix or ControlLogix systems. Existing installations may continue to function reliably, but for long-term projects, newer platforms are recommended. Users are encouraged to plan for future replacements or upgrades.