Overview
The Allen-Bradley 1746-NI16I is a high-resolution analog current input module designed for SLC 500 chassis-based PLC systems. This 16-point module accepts standard industrial current signals (±20 mA, 4–20 mA, 0–20 mA) and converts them to digital data stored in the controller’s image table. With 16-bit resolution and Sigma-Delta conversion technology, it delivers precise analog monitoring for sensor data, transmitter outputs, and process control applications.
Key Features
- 16 input channels — high-density current signal monitoring in a single-slot form factor
- 16-bit resolution — accurate analog-to-digital conversion with Sigma-Delta architecture
- Multi-signal compatibility — accepts ±20 mA, 4–20 mA, 0–20 mA, and isolated group commons for noise immunity
- Low backplane current draw — 125 mA at 5 VDC, 75 mA at 24 VDC; thermal dissipation under 2.5 W
- High isolation — 500 VAC and 710 VDC (tested 60 seconds) protects against surges
- Industrial bandwidth — 6–250 Hz response range for real-world process dynamics
Technical Specifications
- Input Channels: 16 single-ended, 4 isolated groups of 4 inputs
- Input Signal Range: ±20 mA, 4–20 mA, 0–20 mA standard; configurable for ±10 V, 1–5 V, 0–10 V, 0–50 V, 0–1 mA
- Resolution: 16-bit
- Conversion Method: Sigma-Delta
- Input Impedance: 249 ohms
- Maximum Input Voltage: ±8 V (between terminal and analog common)
- Maximum Input Current: ±30 mA (input to analog)
- Backplane Current (5 VDC): 125 mA
- Backplane Current (24 VDC): 75 mA
- Power Consumption: 2.425 W maximum (0.625 W at 5 VDC, 1.8 W at 24 VDC)
- Isolation Voltage: 500 VAC / 710 VDC (60 seconds)
- Common Mode Voltage: ±10.25 V (relative to analog common)
- Bandwidth: 6–250 Hz
- Operating Temperature: −25 to +60 °C (−13 to +140 °F)
- Non-Operating Temperature: −40 to +85 °C (−40 to +185 °F)
- Humidity (Operating): 5–95% without condensation
- Mounting: Single-slot SLC 500 chassis
- Weight: 0.75 lbs
- Connection: Plug-in to backplane
Typical Applications
- Industrial process monitoring — temperature, pressure, and flow rate data acquisition
- Sensor signal conditioning — direct interface to 4–20 mA transmitters and instrumentation
- Legacy system retrofit — replacement analog input in existing SLC 500 installations
- Data logging and SCADA integration — precise current signal capture for supervisory control
- Machine automation — analog feedback from position sensors, load cells, and transducers
Compatibility & Replacements
Compatible With
- SLC 500 fixed and modular chassis (1746 series)
- SLC 500 processors (all models)
- Analog input wiring — 1492-ACAB pre-wired RTB cables (0.5, 1, 2.5, 5 meter lengths)
- Studio 5000 Logix Designer (legacy SLC program upload/download)
- Allen-Bradley I/O libraries and documentation
Replaces / Drop-In Replacement For
- 1746-NI16IA (Series A variant)
- 1746-NI16I / 1746-NI161A (legacy part numbers)
Works With
- SLC 500 programming software (RS Logix 500, Studio 5000)
- Modbus, EtherNet/IP gateway modules (via separate communication interface)
- Standard 24 VDC backplane power supplies
- Isolated 4–20 mA loop networks
