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FANUC Controller

Program/G-code · Basic · 10-20 minutes

Alarm 1091

Fanuc Alarm 1091 - DUPLICATE SUB-CALL WORD

Fanuc Alarm 1091 DUPLICATE SUB-CALL WORD occurs when a program block contains more than one subprogram call instruction (M98, G65, or M198). The CNC controller can only process one subprogram call per block, and duplicate call words create ambiguity in program execution order.

FANUCProgram/G-codeBasic10-20 minutes

1091

Fanuc Alarm 1091 - DUPLICATE SUB-CALL WORD

SYSTEM ALARM 1091

Fanuc alarm 1091: SYSTEM ALARM 1091. This alarm indicates a fault condition detected by the Fanuc control. Refer to the alarm number and name to identify the specific system or function involved.

Root Cause Summary

Fanuc Alarm 1091 DUPLICATE SUB-CALL WORD occurs when a program block contains more than one subprogram call instruction (M98, G65, or M198). The CNC controller can only process one subprogram call per block, and duplicate call words create ambiguity in program execution order.

Causes and Fixes

  1. 1

    Enter EDIT mode and search the program for the block number referenced in the alarm message. Look for syntax like 'M98 P1000 M98 P2000' or 'M98 P1000 M198 P5000' in the same line.

  2. 2

    Separate the duplicate subprogram calls into individual blocks. Each M98 or M198 command must be on its own block with unique sequence number.

    Ensure the execution order matches the intended machining sequence when splitting calls into separate blocks.

  3. 3

    If using P-code format with repeat count (M98 P1000 L5), verify no additional M98/M198 exists in same block. The L-word repeat is valid within single M98 call.

  4. 4

    Reset the alarm using RESET key and verify program syntax in background edit. Run a dry run test cycle to confirm proper subprogram calling sequence.

DIY Feasiblehigh confidence

Call a technician if:

  • ·Parameter corruption suspected
  • ·Repeated alarms after program corrections
  • ·System macro variables affected

Prevention

  • Always use one subprogram call per block
  • Enable program format checking parameters
  • Use consistent programming standards for subprogram calls
  • Validate programs with CHECK function before execution

Common Mistakes

  • Combining M98 with G65 in same block
  • Using multiple P-words with single M98
  • Copy-pasting without checking block structure
  • Mixing macro assignments with subprogram calls

Related Alarms

1090109210936010

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