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ErrorLib — Industrial Fault Code Library

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86

Reader/Puncher Interface Alarm

Fanuc · Series 20 CNC

What does 86 mean?

This alarm indicates an issue with the communication or interface between the CNC (Fanuc Series 20) and an external reader/puncher device. It prevents proper data input or output operations.

Common Causes

  • Incorrect connection or wiring of the reader/puncher interface cable.
  • Improper settings of the reader/puncher parameters (e.g., baud rate, data bits, stop bits, parity).
  • Malfunction of the external reader/puncher device itself.
  • Noise interference affecting serial communication lines.
  • Issue with the CNC's interface circuit board.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify all cable connections between the CNC and the reader/puncher device for proper seating and integrity.

  2. 2

    Check the reader/puncher interface parameters in the CNC (e.g., Parameters 10-14 for I/O channel settings) and on the external device, ensuring they match.

  3. 3

    Test the reader/puncher device with another known good CNC or test the CNC with a known good external device if possible.

  4. 4

    Inspect the communication lines for signs of damage or excessive electrical noise. Ensure proper grounding.

  5. 5

    If the issue persists after external checks, consider that the CNC's I/O interface board may be faulty.

Browse all codes in this manual (43)
Verified technical data. Last updated: April 2026

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Source: Fanuc Series 20 CNC
Open Manual (Page 7)Search more codes in this manual