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Measurement Computing ADAC-LVi User Manual

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Chapter 2 Buffer Config Library

ADAC LabVIEW VI

107

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Device Handle (0) Device Handle is a numeric value that is used to identify the device
subsystem. The default Device Handle is 0.

BUFFER NUMBER (-1:next) Specifies the ID number of the buffer from which the
status information is obtained.
If Buffer Number is set to -1 the status is obtained from the next available LDSD buffer.

error in (no error) Error in describes error conditions occurring before this VI executes.
This cluster defaults to no error.

Device Handle out Device Handle out contains the value of Device Handle in.

BUFFER STATUS ADAC-LVi buffers are not just arrays of data to a DAQ board's
subsystem data, but are structures that contains the buffer type, size, data array, current
sample count, hardware trigger points, completion flags, status flags, and error flags.
Some of these fields remain constant for the duration of the acquisition. Others contain
relevant information about the current condition of the buffer, and error conditions that
can occurred during the current acquisition.

The three structure variables that provide state/status/error information are the DoneFlag,
StatusFlag and ErrorFlags.

BufferType [U32] BufferType
Data Buffer type, DMA, Interrupt or Polling.

BufferSize [U32] BufferSize
Size of the buffer in bytes.

BufferWrite [U32] BufferWrite
Number of data samples in the buffer.

BufferRead [U32] BufferRead
Number of data samples obtained from a buffer.

TriggerPoint [U32] TriggerPoint
Buffer position number of the trigger point.

TiggerPointPre [U32] TriggerPointStart
Buffer position number of the pre-trigger data.

DoneFlag [U32] DoneFlag:
The Done Flag specifies the current state of a buffer. This flag can be set to any
of the three following conditions.