NI FGEN Interchangeability Info Functions

Interchangeability Info Functions

• niFgen_GetNextInterchangeWarning
• niFgen_ClearInterchangeWarnings
• niFgen_ResetInterchangeCheck

niFgen_GetNextInterchangeWarning

ViStatus niFgen_GetNextInterchangeWarning (ViSession vi, ViInt32 bufferSize, ViChar[] interchangeWarning);

Purpose

Returns the interchangeability warnings associated with the IVI session. It retrieves and clears the oldest instance in which the class driver recorded an interchangeability warning. Interchangeability warnings indicate that using your application with a different instrument might cause different behavior. Use this function to retrieve interchangeability warnings.

NI-FGEN performs interchangeability checking when the NIFGEN_ATTRIBUTE_INTERCHANGE_CHECK attribute is set to VI_TRUE.

The function returns an empty string in the interchangeWarning parameter if no interchangeability warnings remain for the session.

In general, NI-FGEN generates interchangeability warnings when an attribute that affects the behavior of the instrument is in a state that you did not specify.

Parameters

Input
Name	Type	Description
vi	ViSession	Identifies your instrument session. vi is obtained from the niFgen_init, niFgen_InitWithOptions, or niFgen_InitializeWithChannels functions and identifies a particular instrument session.
bufferSize	ViInt32	Specifies the number of bytes in the ViChar array you specify for the interchangeWarning parameter. If the next interchangeability warning string, including the terminating NUL byte, contains more bytes than you indicate in this parameter, the function copies bufferSize – 1 bytes into the buffer, places an ASCII NUL byte at the end of the buffer, and returns the buffer size that you must pass to get the entire value. For example, if the value is 123456 and bufferSize 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 interchangeWarning buffer parameter. Default Value: None
Output
Name	Type	Description
interchangeWarning	ViChar[]	Returns the next interchange warning for the IVI session. If there are no interchange warnings, the function returns an empty string. The buffer must contain at least as many elements as the value you specify with the bufferSize parameter. If the next interchangeability warning string, including the terminating NUL byte, contains more bytes than you indicate with the bufferSize parameter, the function copies bufferSize – 1 bytes into the buffer, places an ASCII NUL byte at the end of the buffer, and returns the buffer size that you must pass to get the entire value. For example, if the value is 123456 and bufferSize is 4, the function places 123 into the buffer and returns 7. This parameter returns an empty string if no interchangeability warnings remain for the session.

Return Value

Name	Type	Description
Status	ViStatus	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. You can examine the status code from each call to an NI-FGEN function to determine if an error occurred. To obtain a text description of the status code, call niFgen_error_message. To obtain additional information about the error condition, call niFgen_GetError. To clear the error information from NI-FGEN, call niFgen_ClearError. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors

niFgen_ClearInterchangeWarnings

ViStatus niFgen_ClearInterchangeWarnings (ViSession vi);

Purpose

Clears the list of current interchange warnings.

Parameters

Input
Name	Type	Description
vi	ViSession	Identifies your instrument session. vi is obtained from the niFgen_init, niFgen_InitWithOptions, or niFgen_InitializeWithChannels functions and identifies a particular instrument session.

Return Value

Name	Type	Description
status	ViStatus	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. You can examine the status code from each call to an NI-FGEN function to determine if an error occurred. To obtain a text description of the status code, call theniFgen_error_message function. To obtain additional information about the error condition, call the niFgen_GetError function. To clear the error information from NI-FGEN, call the niFgen_ClearError function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors

niFgen_ResetInterchangeCheck

ViStatus niFgen_ResetInterchangeCheck (ViSession vi);

Purpose

This function tests the current test module for dependencies on the operation of previously executed test modules. If your module depends on the operation of previous modules, your test system has less flexibility.

When developing a complex test system that consists of multiple test modules, NI recommends that you design the test modules so that they can run in any order. To do so, ensure that each test module completely configures the state of each instrument it uses. If a particular test module does not completely configure the state of an instrument, the state of the instrument depends on the configuration from a previously executed test module. If you execute the test modules in a different order, the behavior of the instrument and the test module may change. This change in behavior is generally instrument specific and represents an interchangeability problem.

After you call this function, the interchangeability checking algorithms in the specific driver ignore all previous configuration operations. By calling this function at the beginning of a test module, you can determine whether the test module has dependencies on the operation of previously executed test modules.

This function does not clear the interchangeability warnings from the list of previously recorded interchangeability warnings. If you want to guarantee that the niFgen_GetNextInterchangeWarning function only returns those interchangeability warnings that are generated after calling this function, you must clear the list of interchangeability warnings. You can clear the interchangeability warnings list by repeatedly calling the niFgen_GetNextInterchangeWarning function until no more interchangeability warnings are returned. If you are not interested in the content of those warnings, you can call the niFgen_ClearInterchangeWarnings function.

Parameters

Input
Name	Type	Description
vi	ViSession	Identifies your instrument session. vi is obtained from the niFgen_init, niFgen_InitWithOptions, or niFgen_InitializeWithChannels functions and identifies a particular instrument session.

Return Value

Name	Type	Description
status	ViStatus	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. You can examine the status code from each call to an NI-FGEN function to determine if an error occurred. To obtain a text description of the status code, call theniFgen_error_message function. To obtain additional information about the error condition, call the niFgen_GetError function. To clear the error information from NI-FGEN, call the niFgen_ClearError function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors