Ivi_GetNthChannelString
Usage
ViStatus Ivi_GetNthChannelString(ViSession vi, ViInt32 index, ViConstString* channelString);
Purpose
The function returns the channel string that is in the channel table at an index you specify. The specific instrument driver specifies the contents of the channel table using Ivi_BuildChannelTable and Ivi_AddToChannelTable, and the IVI engine maintains the table for the session.
If the index you specify is greater than the number of channel strings in the table, the function sets the Channel String parameter to VI_NULL and returns VI_SUCCESS.
Parameters
| Name | Type | Description |
|---|---|---|
| vi | ViSession |
The ViSession handle that you obtain from Ivi_SpecificDriverNew. The handle identifies a particular IVI session. |
| index | ViInt32 |
A 1-based index into the channel table. If you pass an index that is greater than the number of strings in the table, the function sets the Channel String parameter to VI_NULL and returns VI_SUCCESS. |
| channelString | ViConstString* |
Returns the channel string that is in the channel table at the index you specify. Do not modify the contents of the channel string. If the Index parameter is greater than the number of strings in the table, the function sets this parameter to VI_NULL and returns VI_SUCCESS. |
Return Value
Contains the status code that the function call returns. IVI engine functions can return error and warning values from several sets of status codes. Some status codes are unique to the IVI engine. Other status codes are the same codes that VISA Library functions return. Still others are error or warning values that functions in specific instrument drivers return. Each set of status codes has its own numeric range.
Regardless of the source of the status code, 0 always indicates success, a positive value indicates a warning, and a negative value indicates an error.