NI SCOPE Error Handling Functions
ViStatus niScope_errorHandler (ViSession vi, ViInt32 errorCode, ViChar errorSource[MAX_FUNCTION_NAME_SIZE], ViChar errorDescription[MAX_ERROR_DESCRIPTION]);
Takes the error code returned by NI-SCOPE functions and returns the interpretation as a user-readable string.
 |
Note You can pass VI_NULL as the instrument handle, which is useful to interpret errors after niScope_init has failed. |
|---|
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| errorCode | ViStatus | The error code that is returned from any of the instrument driver functions. |
| errorSource[] | ViChar |
Specifies the function in which the error occurred. You can pass in a string no longer than MAX_FUNCTION_NAME_SIZE. If you pass in a valid string, this source is included in the errorDescription string. For example: "Error <errorCode> at <errorSource>" If you pass in NULL or an empty string, this parameter is ignored. |
| Output | ||
| Name | Type | Description |
| errorDescription[] | ViChar | Returns the interpreted error code as a user readable message string; you must pass a ViChar array at least MAX_ERROR_DESCRIPTION bytes in length. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_GetError (ViSession vi, ViStatus* errorCode, ViInt32 bufferSize, ViChar[] description);
|
Note This function is included for compliance with the IviScope Class Specification. |
|---|---|
| Reads an error code and message from the error queue. National Instruments digitizers do not contain an error queue. Errors are reported as they occur. Therefore, this function does not detect errors. |
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| errorCode | ViStatus* | Pass the Error Code that is returned from any of the instrument driver functions. |
| Output | ||
| Name | Type | Description |
| bufferSize | ViInt32 |
Passes the number of bytes in the ViChar array you specify for the Description parameter. If the error description, including the terminating NULL byte, contains more bytes than you indicate in this parameter, the function copies bufferSize – 1 bytes into the buffer, places an ASCII NULL byte at the end of the buffer, and returns the buffer size you must pass to get the entire value. For example, if the value is "123456" and the Buffer Size is 4, the function places "123" into the buffer and returns 7. If you pass a negative number, the function copies the value to the buffer regardless of the number of bytes in the value. If you pass 0, you can pass VI_NULL for the description parameter. |
| description | ViChar[] |
Returns the error description for the IVI session or execution thread. If there is no description, the function returns an empty string. The buffer must contain at least as many elements as the value you specify with the Buffer Size parameter. If you pass 0 for the bufferSize, you can pass VI_NULL for this parameter. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_GetErrorMessage (ViSession vi, ViStatus errorCode, ViInt32 bufferSize, ViChar errorMessage[]);
Returns the error code from an NI-SCOPE function as a user-readable string. Use VI_NULL as the default instrument handle.
You must call this function twice. For the first call, set bufferSize to 0 to prevent the function from populating the error message. Instead, the function returns the size of the error string. Use the returned size to create a buffer, then call the function again, passing in the new buffer and setting bufferSize equal to the size that was returned in the first function call.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| errorCode | ViStatus | The error code that is returned from any of the instrument driver functions. |
| bufferSize | The number of characters you specify for the errorMessage parameter. | |
| Output | ||
| Name | Type | Description |
| errorMessage[] | ViChar | Returns a char buffer that will be populated with the error message. It should be at least as large as the buffer size. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |