The Siemens Masterdrive fault code F138 indicates an issue with the Technology Board Fault. This board is an optional add-on module for some Siemens Masterdrive models. It expands the drive's functionality by providing features like:

• Advanced control algorithms: The board might offer additional control capabilities beyond the standard functionality of the drive.
• Increased encoder functionality: It could support more complex encoder types or provide additional encoder processing features.
• Expanded communication options: In some cases, the  board might offer additional communication interfaces beyond the standard capabilities of the drive.

Here's a breakdown of the problem:

• Cause: The drive encountered an error related to the board. This can happen due to various reasons.

Possible Causes:

• Missing or Incompatible Board: The board might not be properly inserted, or it could be incompatible with your specific drive model.
• Communication Interface Issue (if applicable): If the board provides additional communication features, there could be an issue with the specific communication interface used.
• Hardware Fault: Compared to other optional boards like CBs or TBs, boards handle more complex control algorithms and might be more prone to internal hardware malfunctions.