"Internal diagnostic capabilities" in devices means:

1. _Built-in test (BIT) software_: Devices have embedded software that can run self-tests and diagnostics.

2. _Diagnostic algorithms_: Devices use algorithms to analyze data and identify potential issues.

3. _Sensor data analysis_: Devices can analyze data from sensors to detect anomalies or errors.

4. _Error code generation_: Devices can generate error codes or messages to indicate specific issues.

5. _Self-test capabilities_: Devices can perform self-tests to verify functionality and detect errors.

6. _Real-time monitoring_: Devices can monitor their own performance and detect issues in real-time.

7. _Fault isolation_: Devices can isolate faults to specific components or systems.

8. _Automatic logging_: Devices can automatically log errors and diagnostic data for later analysis.

Internal diagnostic capabilities enable devices to proactively identify and diagnose issues, reducing downtime and increasing overall reliability and efficiency.