niDMM_ReadStatus
ViStatus = niDMM_ReadStatus(ViSession Instrument_Handle, ViInt32 *Acquisition_Backlog, ViInt16 *Acquisition_Status)
Purpose
Returns measurement backlog and acquisition status. Use this function to determine how many measurements are available before calling niDMM_Fetch, niDMM_FetchMultipoint, or niDMM_FetchWaveform.
 |
Note The NI 4050 is not supported. |
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.
|
| Output |
| Name |
Type |
Description |
| Acquisition_Backlog |
ViInt32* |
The number of measurements available to be read. If the backlog continues to increase, data is eventually overwritten, resulting in an error.
|
Note On the NI 4060, the Backlog does not increase
when autoranging. On the NI 4065, the Backlog
does not increase when Range is set to AUTO RANGE ON (-1), or before the first point is fetched when Range is set to AUTO RANGE ONCE (-3). These behaviors are due to the autorange model of the devices. |
|
| Acquisition_Status |
ViInt16* |
Indicates status of the acquisition. The following table shows the acquisition states:
| 0 |
Running |
| 1 |
Finished with backlog |
| 2 |
Finished with no backlog |
| 3 |
Paused |
| 4 |
No acquisition in progress |
|
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. |