OVERVIEW

Official designation: Allen-Bradley 1492-IFM20D120 (Bulletin 1492, Digital Interface Module)

Role/Application: Digital interface module for industrial control, converting PLC I/O signals to field wiring connections and providing 120 V AC/DC LED status indication and diagnostics.

KEY SPECS SUMMARY

Power: 85 to 132 V AC/DC

Interfaces / Ports: Fixed Terminal Block, 20-Pin cable connector

Indicators: LED Indicating (Nominal Current: 2.5 mA)

Operating Temp: Refer to the latest manufacturer manual.

Platform / Compatibility: DIN rail mountable, PLC I/O wiring system

Limit: 2 A max circuit, 12 A max module

Lifecycle: Active, Refer to the latest manufacturer manual.

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the nominal current draw for the 120 V AC/DC indicator LEDs?

A: The nominal indicator circuit current draw is rated at 2.5 mA.

Wiring & Installation:

Q: Are there any special requirements when wiring to an inductive load?

A: Surge suppression (e.g., a diode or MOV) must be used with hard contact output circuits switching an inductive load.

Troubleshooting & Compatibility:

Q: Can this IFM be used with an input module that has high off-state leakage current?

A: No, it is not recommended for input circuits exceeding 0.5 mA off-state leakage current; use the N or A-2 versions instead.

Replacement & Upgrades:

Q: What is the primary benefit of using this interface module versus direct point-to-point wiring?

A: It provides reduced wiring time, error reduction, and faster field-side troubleshooting via status LEDs.