Overview
The Allen-Bradley 1492-IFM20F-F120-2 is a 20-point fusible digital interface module designed to provide a secure, field-proven connection between PLC I/O modules and external automation equipment. Part of the Bulletin 1492 wiring system, this IFM isolates incoming signals and includes built-in fuse protection with blown fuse indicators for rapid troubleshooting and reduced downtime.
Key Features
- 20-point isolated digital I/O — Protects PLC processors from external voltage transients and field noise
- 5×20mm fuse clips — Fast-acting fuses with visual LED indicators for blown fuses on each circuit
- 120V AC/DC rated — Operates across input ranges 85–132 VAC or equivalent DC
- Extra output terminals — Provides two screw terminals per point (40 total) for flexible wiring and field connections
- Drop-in compatibility — Works directly with ControlLogix 1756, CompactLogix 1769, SLC 500 1746, and PLC-5 1771 backplane modules
Technical Specifications
- Points: 20 digital (isolated)
- Fuse Type: 5×20mm clips, 2A per circuit, 12A per module maximum
- Input Voltage: 85–132 VAC or 10–30 VDC (control circuit)
- Blown Fuse Indicator: LED (red) on each fuse position
- Connectors: 20-pin DIN connector to PLC module; 40 screw terminals (2 rows × 20)
- Connection Type: Fixed terminal block
- Amperage Rating: 2A per circuit, 12A per module
- Standards: CUL, CE, NRTL, UL certified
- Operating Temperature: 0°C to 60°C
- Series: Bulletin 1492, Series A
Typical Applications
- Digital signal conditioning for PLC input/output modules in manufacturing control systems
- Field device termination and fuse protection for motor starters, solenoids, and pilot lights
- Signal isolation in high-noise industrial environments (servo press, hydraulic, packaging machinery)
- OEM and retrofit control panel wiring for discrete I/O integration
Compatibility & Replacements
Compatible With
- Allen-Bradley ControlLogix 1756 I/O modules
- Allen-Bradley CompactLogix 1769 I/O modules
- Allen-Bradley SLC 500 1746 I/O modules
- Allen-Bradley PLC-5 1771 I/O modules
- MicroLogix 1200 (40 I/O base only) and MicroLogix 1500 packaged controllers
- PowerFlex 700H and 700S variable frequency drives (select models)
- Bulletin 1492 pre-wired cable assemblies
Replaces / Drop-In Replacement For
- 1492-IFM20F-F120-2 Series A (same part — direct equivalent)
- Verify compatibility with your system integrator before ordering legacy model cross-references
Works With
- Studio 5000 Logix Designer software (I/O module configuration)
- RSLogix 5000 / RSLogix 500 (programming and diagnostic tools)
- Proprietary Allen-Bradley Bulletin 1492 wiring harnesses and terminal blocks
- EtherNet/IP and ControlNet networks (via parent I/O module)
