Allen Bradley 1492-IFM40F Feed-Through Digital Interface Module

Configured for discrete signal termination in ControlLogix and PLC-5 I/O systems, the Allen Bradley 1492-IFM40F (1492-IFM40F Feed-Through Interface Module) provides direct physical and electrical execution of 40-point digital field signal distribution.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks

The 1492-IFM40F module serves as a passive interface link within automation architectures, facilitating the transition from field cabling to PLC I/O cards. While the interface is passive, its application must be synchronized with the backplane bus communication velocity of the connected controller to maintain signal timing. The module supports I/O density scaling by grouping 40 points, allowing for structured wiring configurations. Firmware flash compatibility is not applicable, as the module functions as a feed-through terminal block. Users must verify the electrical load limits of the connected I/O circuits to ensure they do not exceed the 132 V AC/DC maximum threshold.

Frequently Asked Questions

Q: Does this module perform signal isolation?

A: No. The 1492-IFM40F is a feed-through interface module and does not provide galvanic or optical isolation between field inputs and the PLC I/O card.

Q: Is this module compatible with all 40-point I/O cards?

A: Compatibility depends on the specific pinout of the I/O card and the cabling used. Ensure the wiring interface cable matches the pin assignment of the 1492-IFM40F terminal block to prevent wiring errors.

Field Installation Guidelines

1. Mounting: Secure the interface module onto a 35 mm DIN rail. Ensure the module is snapped firmly into position to maintain mechanical stability in high-vibration environments.
2. Wiring: Use wire ferrules for all field terminations to ensure a consistent, low-resistance connection. Torque all terminal screws to the manufacturer-specified value.
3. Shielding: Terminate cable shields at the designated ground lug on the cabinet backplane to mitigate EMI. Do not leave floating shields, as they can act as antennas for noise.
4. Segregation: Separate AC and DC wiring runs within the wire ducts to reduce the risk of cross-coupling noise into the digital input circuits.
5. Verification: Prior to energizing the system, verify continuity between field sensors and the PLC input registers using a multimeter to confirm correct point mapping.