251-0D96

Access Oscilloscope Function

Press MOD key, navigate to Oscilloscope function. Observe if any configurations are currently active or in error state.

On TNC 640 and newer, the Oscilloscope is found under MOD > Service > Oscilloscope. On iTNC 530/TNC 530, it may be under MOD > Test > Oscilloscope depending on software version.

Delete Active Oscilloscope Configurations

Within the Oscilloscope menu, delete all existing trace configurations and saved recordings. Use the configuration management softkeys to clear all setups.

This will delete any saved oscilloscope traces. Export important traces to external storage first if needed.

Clear Alarm and Power Cycle

Clear the alarm using the CE key. Perform a complete power-down of the control (not just software restart). Wait 30 seconds, then power back up to force complete reinitialization of the oscilloscope subsystem.

Test Oscilloscope Function

After restart, access MOD > Oscilloscope and create a simple new configuration (e.g., monitoring axis X position). Start recording to verify communication is restored.

Start with a single channel monitoring a basic signal like axis position or commanded velocity to minimize resource load during testing.

Check System Memory Status

Navigate to MOD > System Information (or MOD > Service > System Info on TNC 640). Review available RAM and memory usage statistics. Note any warnings about low memory.

The oscilloscope typically requires 8-16 MB of contiguous memory depending on sampling rate and channel count. System should show at least 50 MB free for reliable operation.

Close Unnecessary Applications

Exit all open programming stations, graphics simulations, and any external software running on the control. Close unused NC programs and clear the program memory if not needed.

Do not close PLC or NC kernel processes. Only close user-level applications.

Perform NC Software Restart

Access MOD > Service > Restart NC Software (exact path varies by control version). This performs a warm restart that reinitializes memory allocation without full power cycle.

This restart is faster than power cycling and often sufficient to clear memory fragmentation issues affecting the oscilloscope.

Reduce Oscilloscope Configuration Demands

If alarm persists, configure oscilloscope with reduced sampling rate and fewer channels. Access oscilloscope settings and set sampling rate to minimum acceptable value (e.g., 1 ms instead of 0.1 ms).

High sampling rates exponentially increase memory requirements. For most diagnostic work, 1-2 ms sampling is sufficient and uses 10x less memory than 0.1 ms sampling.

Check Software Version Information

Navigate to MOD > Service > Version Information. Document the NC Software version number and the versions of all listed modules. Look specifically for 'Oscilloscope Module' or 'Scope Service' entries.

On TNC 640, all module versions should match the first two digits of the NC software version (e.g., if NC is 340.590-xx, scope should be 340.xxx-xx).

Review Recent Update History

Check if a software update was performed recently. Access MOD > Service > Update History if available, or check maintenance logs for recent update activities.

If update was interrupted or incomplete, additional issues may be present beyond just oscilloscope communication.

Perform Complete Software Update

If version mismatch is found, obtain the complete software update package from Heidenhain for your control model. Perform a full software update following the Update Installation procedure in MOD > Service > Software Update.

Backup all machine parameters, PLC programs, and NC programs before performing software update. Ensure UPS or stable power during update process.