Heidenhain codes
HeidenhainCommunicationIntermediate30-120 minutes

235-00A8

HEIDENHAIN 235-00A8 - Überzähliger Umrichter an HSCI-Gerät

Überzähliger Umrichter an HSCI-Gerät

In an HSCI device, extra inverters are connected that were not configured. These need to be removed or the configuration adjusted.

Root Cause Summary

HEIDENHAIN alarm 235-00A8 occurs when the TNC control detects additional drive inverters connected to an HSCI device that are not configured in the machine parameters. This typically happens when hardware configuration options don't match the physical drive setup or when extra drives are physically connected but not declared in the system configuration.

Safety

  • Refer to Heidenhain service manual
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Access Machine Parameters

    Press MOD key, select 'Machine Parameters' menu, navigate to MP7300 series (HSCI configuration parameters).

    Document current settings before making changes

  2. 2

    Verify Drive Configuration

    Check MP7301 (number of drives) and MP7302-MP7309 (individual drive assignments) against physical hardware setup.

    Incorrect drive parameters can cause axis runaway

  3. 3

    Update Configuration

    Modify MP7301 to match actual drive count and configure individual drive parameters MP7302-MP7309 for each connected inverter.

    Use the alarm display values %1, %3, %4, %5 to identify specific drive types and serial numbers

  4. 4

    Restart Control

    Perform complete TNC restart (CTRL+ALT+DEL) to reinitialize HSCI communication with new parameters.

DIY Feasiblehigh confidence

Call a technician if:

  • ·Parameter restoration doesn't clear alarm
  • ·Multiple HSCI communication errors persist
  • ·Drive hardware appears physically damaged

Prevention

  • Regular backup of machine parameters
  • Document all hardware configuration changes
  • Verify HSCI addresses before connecting new drives

Common Mistakes

  • Modifying MP7301 without updating individual drive parameters
  • Disconnecting HSCI cables while system is powered
  • Ignoring drive serial numbers when configuring parameters

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Always verify with your machine manual or a certified technician before performing service procedures.