Overview
The Allen-Bradley 1771-IVN Series B is a PLC-5 discrete digital input module that provides 32 channels of 10-30VDC signal conditioning. Designed for use in 1771-series I/O chassis, this low-true input module converts external DC device signals into logic-level inputs for the PLC-5 controller. It features built-in isolation, filtering, and per-channel LED diagnostics for industrial automation and machine control systems.
Key Features
- 32 Digital Inputs: Organized in four groups of eight, supporting modular wiring and power distribution.
- 10-30VDC Input Range: Nominal input current of 4.5mA @ 10V DC, optimized for low-power sensing applications.
- Low-True Logic: Source input module that requires a sink output; a source input provides a positive voltage path and a sink output provides a path to ground.
- Optoelectrical Isolation: Protects controller circuits from field-side transients.
- Input Filtering: Typical 6 ms on/off delay reduces electrical noise and false triggering.
- LED Status Indicators: 32 status indicators on the module front plate representing the control status of the inputs; each indicator is lit when voltage is present at the corresponding input.
Technical Specifications
- Input Points: 32 (4 groups × 8)
- Input Voltage Range: 10–30V DC
- Nominal Input Current: 4.5 mA @ 10V DC
- Input Logic: Low-True (source)
- Filter Response: Typical 6 ms on/off delay
- Backplane Current Draw: 280 mA from the output of the chassis power supply
- Chassis Compatibility: Series B 1771 I/O chassis (1771-A1B thru -A4B)
- Wiring Terminal: 1771-WN field wiring arm
- Isolation: Optoelectrical
- Operating Environment: Conformal-coated for industrial conditions
Typical Applications
Interfacing pushbuttons, switches, sensors, and other source-switching DC devices within PLC-5 automation systems. Common uses include discrete sensor monitoring, push-button input acquisition, alarm status capture, and machine safety interlocks in manufacturing and process control systems.
Compatibility & Replacements
Compatible With
- PLC-5/15, Series B and later
- 1771-A1B, -A2B, -A3B, -A4B I/O chassis
- 1771-WN field wiring arm
- Mini-PLC-2/02, -2/16, -2/17 controllers
- PLC-2/20, PLC-2/30 systems
- PLC-3 and PLC-3/10 controllers
Replaces / Drop-In Replacement For
The 1771-IVN Series B is a direct replacement for earlier Series A units in low-true applications. When specifying replacements or upgrades, verify the input logic requirement (low-true vs. high-true) with your system integrator. The 1771-IBN provides a high-true alternative for applications requiring inverted logic.
Works With
- PLC-5 controllers and programming software (RSLogix, Studio 5000)
- Rockwell Automation 1771-series I/O architecture
- DC voltage sources (10–30V DC) with sinking output capability
- 1771-WN wiring terminals for tool-free module removal
