niFgen_GetAttributeViSession
ViStatus niFgen_GetAttributeViSession (ViSession vi, ViConstString channelName, ViAttr attributeID, ViSession* attributeValue);
Purpose
Queries the value of a ViSession attribute.
You can use this function to get the values of instrument-specific attributes and inherent IVI attributes. If the attribute represents an instrument state, this function performs instrument I/O in the following cases:
- State caching is disabled for the entire session or for the particular attribute.
- State caching is enabled and the currently cached value is invalid.
Parameters
| Input | ||
| Name | Type | Description |
| vi | ViSession | Identifies your instrument session. vi is obtained from the niFgen_init or the niFgen_InitWithOptions functions and identifies a particular instrument session. |
| channelName | ViConstString | Specifies the name of the channel on which to check the attribute value if the attribute is channel-based. If the attribute is not channel-based, then pass VI_NULL or an empty string ("").
Default Value: "" (empty string) |
| attributeID | ViAttr | Specifies the ID of an attribute. |
| Output | ||
| Name | Type | Description |
| attributeValue | ViSession* | Returns the current value of the attribute. Pass the address of a ViSession variable. |
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 the niFgen_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:
|