niDMM_GetAttributeViReal64
ViStatus = niDMM_GetAttributeViReal64(ViSession Instrument_Handle, ViConstString Channel_Name, ViAttr Attribute_ID, ViReal64 *Attribute_Value)
Purpose
Queries the value of a ViReal64 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 |
| Instrument_Handle | ViSession | Identifies a particular instrument session. You obtain the Instrument_Handle parameter from niDMM_init or niDMM_InitWithOptions. The default is None. |
| Channel_Name | ViConstString | This parameter is ignored. National Instruments DMMs do not support channel names since they only have a single channel. This parameter is included in order to support interchangeability and upgradability to multiple channel DMMs.
The default value is " " (an empty string). |
| Attribute_ID | ViAttr | Pass the ID of an attribute. |
| Output | ||
| Name | Type | Description |
| Attribute_Value | ViReal64* | Returns the current value of the attribute. Pass the address of a ViReal64 variable. |
Return Value
| Name | Type | Description |
| Status | ViStatus | Reports the Status of this operation. To obtain a text description of the status code, call niDMM_error_message. To obtain additional information concerning the error condition, use niDMM_GetError. |