Top Heidenhain CNC Error Codes Explained & How To Fix

Heidenhain controls show numbered NC error messages that reflect real conditions - PLC interlocks, encoder systems, file access, internal control checks, and axis limits. 

Error 120-001E - CAN’T CONNECT TO NETWORK

What it means
The control cannot connect to a network drive defined in the network settings.

Common causes

• Network share or server offline
• Wrong share path
• Invalid credentials or permissions
• Bad Ethernet cable or switch port

How to fix

• Confirm the server/share is reachable from another PC on the same network
• Check the control’s IP, gateway, and DNS settings
• Re-enter credentials and re-save the share mapping
• Replace cable or move to another switch port

Error 120-001F - FILE NOT FOUND

What it means
A required file specified by the operator or program cannot be found.

Common causes

• Wrong filename or directory
• USB or storage device not mounted
• File was renamed or deleted

How to fix

• Confirm exact filename and location (including extension)
• Re-mount the USB or network drive and refresh directory view
• Search the control storage for the file and correct the program call/path

Error 130-00A7 - PROGRAM INCOMPLETE

What it means
Unexpected end of file detected in the NC program.

Common causes

• Program transfer interrupted
• File truncated during copy
• Editing mistake that removed ending blocks

How to fix

• Re-transfer the program from the source (do not reuse the same partial file)
• Compare file size against the original
• Open the program and check the last blocks for missing content

Error 140-0021 - DATA OBJECT RENAMED

What it means
Configuration data belongs to an older level and was updated by the control.

Common causes

• Control software update
• Restored older configuration package

How to fix

• Review updated configuration values and machine behavior
• Save the current configuration backup after verification
• If anything changed unexpectedly, restore from a known-good backup and compare

Error 160-008B - BLOCK FORMAT INCORRECT

What it means
A block in the NC program has invalid syntax.

Common causes

• Typo in a block
• Unsupported word/order for the control version
• Wrong post-processor output

How to fix

• Use the cursor to jump to the block indicated by the control
• Correct the syntax (spacing, commas, missing values)
• If it comes from CAM, fix the post and repost the program

Error 201-093F - MEAS. CYCLE: LENGTH EXCEEDS MAX

What it means
A probing or measuring cycle returned a length/value beyond the permitted maximum.

Common causes

• Probe contacted the wrong surface
• Wrong datum or expected size in the cycle
• Probe calibration drift
• Setup error (part not seated, fixture shift)

How to fix

• Verify part seating and fixture position
• Re-check the probing cycle inputs (expected values, tolerances)
• Recalibrate the probe and rerun a simple reference measurement

Error 230-001F - MAX. TRAVERSE LIMIT EXCEEDED

What it means
An axis move exceeds the machine’s allowed traverse limits.

Common causes

• Program commands motion beyond travel
• Wrong work offset or datum
• Axis not properly referenced after power-up

How to fix

• Stop, then verify work offsets and datum selection
• Re-reference axes and confirm machine zero
• Correct the program coordinates or safe approach moves

Error 230-00FA / 230-00FB - LIMIT SWITCH EXCEEDED

What it means
Calculated path exceeds positive or negative software limits.

Common causes

• Coordinate system mismatch (wrong offset active)
• Incorrect zero point
• Soft limit parameters too tight for the machine setup

How to fix

• Confirm the active datum and offsets
• Verify the sign and value of the offset (especially after importing job data)
• If limits are correct but too restrictive, review soft limit configuration with maintenance

Error 230-0457 - REFERENCE MARK NOT FOUND

What it means
The control did not detect a reference mark during referencing.

Common causes

• Encoder or scale signal issue
• Dirty or damaged scale
• Broken cable, loose connector, poor shielding
• Mechanical obstruction preventing full travel

How to fix

• Inspect and reseat encoder/scale connectors
• Check cable routing, shielding, and cabinet grounding
• Clean exposed scale areas where applicable
• If repeatable on one axis, test with known-good cable or swap feedback channels if service procedure allows

Error 231-8065 - DC POWERFAIL

What it means
DC link voltage dropped below the defined limit, indicating power instability.

Common causes

• Incoming line power dip or dropout
• Faulty power supply module
• Loose mains connection or contactor issue

How to fix

• Check incoming line voltage stability (especially during spindle start)
• Inspect cabinet contactors, terminals, and fuses for heat marks and looseness
• Review drive diagnostics for DC bus undervoltage history

Error 231-8C40 - SPEED INPUT NOT SAVED

What it means
Encoder speed value could not be latched or stored, often due to signal interruption.

Common causes

• Encoder signal dropouts
• Connector vibration or damaged cable
• Encoder hardware failure

How to fix

• Inspect encoder cable and connectors for strain and movement
• Check for oil ingress at connectors
• If the problem persists on one axis, replace the encoder or cable after verification

Error 230-0020 - INTERNAL MESSAGE SEND FAILED

What it means
Internal communication within the control failed.

Common causes

• Temporary internal bus issue
• CPU overload due to a fault cascade
• Hardware instability

How to fix

• Power cycle the control and retest
• If it returns, export error logs and involve OEM service
• Check cabinet cooling and power quality to rule out instability triggers

Error 230-04A5 - HANDWHEEL NOT SUPPORTED

What it means
Configured handwheel is not supported by the current NC software version.

Common causes

• Hardware and software mismatch
• Incorrect configuration after retrofit or update

How to fix

• Verify the control software version against the installed handwheel model
• Correct the configuration or update to compatible software
• If recently retrofitted, confirm wiring and interface type match the control requirements

How to work faster with Heidenhain errors

• Open the error list and focus on the first error in time order - later errors are often consequences.
• Treat axis and encoder errors as signal integrity problems until proven otherwise - cables, shielding, connectors, grounding.
• Treat limit and traverse errors as coordinate problems first - offsets, datum selection, referencing.
• If you see power-related errors, check line voltage and cabinet connections before swapping drives.

About MDCplus

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