ERROR_COUNTER_TIMEOUT - 1121 (0x461)
A serial I/O operation completed because the timeout period expired. The IOCTL_SERIAL_XOFF_COUNTER did not reach zero.)
Updated: Feb 21, 2026
Technical Background
The ERROR_COUNTER_TIMEOUT error code, with the numeric value of 1121 and hexadecimal representation of 0x461, is a specific Windows API error that indicates a serial I/O operation has completed due to a timeout. This error occurs when the IOCTL_SERIAL_XOFF_COUNTER did not reach zero within the specified time frame.
Error Details
The ERROR_COUNTER_TIMEOUT error code is associated with the Serial Communication Control Block (SCCB) and specifically relates to the IOCTL_SERIAL_XOFF_COUNTER. This control code is used to determine if the XOFF counter has reached zero, which typically indicates that it is safe to resume data transmission. If the timeout period expires before the counter reaches zero, this error is generated.
Common Causes
- Invalid Parameter Values: Incorrect or invalid parameters passed to the
IOCTL_SERIAL_XOFF_COUNTERfunction can lead to a timeout. - Incorrect Object Type: The operation may be applied incorrectly to an object that does not support serial communication operations.
- Exceeding Limits: The system may have reached a limit on the number of concurrent I/O operations or other resource constraints.
Real-World Context
This error can occur in scenarios where serial communication is being managed through device drivers and user-mode applications. It is particularly relevant when dealing with hardware devices that require careful management of flow control signals (XON/XOFF).
Is This Error Critical?
The ERROR_COUNTER_TIMEOUT error, while not critical to the system's overall stability, can indicate issues in serial communication handling. Developers should address this issue to ensure reliable and efficient data transmission.
How to Diagnose
To diagnose the cause of the ERROR_COUNTER_TIMEOUT, developers should:
- Review Operation Context: Ensure that the operation context is correct and that all necessary parameters are valid.
- Validate Parameters: Verify that the parameters passed to the
IOCTL_SERIAL_XOFF_COUNTERfunction are appropriate for the device in question. - Confirm Object Types: Confirm that the object being operated on supports serial communication operations.
How to Resolve
To resolve the ERROR_COUNTER_TIMEOUT, developers should:
- Correct Parameter Usage: Ensure that all parameters passed to the
IOCTL_SERIAL_XOFF_COUNTERfunction are correct and valid. - Adjust Operation Context: If the operation context is incorrect, adjust it to ensure compatibility with the device's capabilities.
Developer Notes
Developers should be aware of the specific requirements for serial communication operations, particularly regarding flow control mechanisms. Ensuring that all parameters are correctly set and that the operation context aligns with the hardware's capabilities can prevent this error from occurring.
Related Errors
- ERROR_TIMEOUT: A general timeout error that may occur in various contexts.
- ERROR_INVALID_PARAMETER: An error indicating invalid parameter values were passed to a function.
FAQ
Q: What does the ERROR_COUNTER_TIMEOUT error indicate?
A: The ERROR_COUNTER_TIMEOUT indicates that a serial I/O operation completed because the timeout period expired, specifically due to the IOCTL_SERIAL_XOFF_COUNTER not reaching zero within the specified time frame.
Q: How can this error be prevented?
A: This error can be prevented by ensuring correct parameter usage and valid operation context. Verify that all parameters are appropriate for the device in question and that the operation context is compatible with the hardware's capabilities.
Summary
The ERROR_COUNTER_TIMEOUT error code, 1121 (0x461), indicates a serial I/O operation timeout due to the IOCTL_SERIAL_XOFF_COUNTER not reaching zero within the specified time frame. Developers should ensure correct parameter usage and valid operation context to prevent this error from occurring.