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Part 2
Introduction to the NI-DSP Analysis VIs
NI-DSP SRM for LabVIEW for Windows
1-5
Part 2: Introduction to the NI-DSP Analysis VIs
Special Features of the NI-DSP Analysis VIs
This section describes the special features of the NI-DSP Analysis VIs that make them different from other
LabVIEW VIs.
LabVIEW VIs.
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DSP Handle Cluster in/out. The way you specify the output data buffers for NI-DSP Analysis VIs is different
from the way you would specify output data buffers for other LabVIEW VIs. DSP Handle Clusters also
represent all the output data buffers in the NI-DSP Analysis VIs. To use valid DSP Handle Clusters for the
NI-DSP VI output data buffers, you must use the DSP Allocate Memory VI to obtain the DSP Handle Clusters
before you use them. Supply all of the output DSP Handle Clusters as inputs to tell the DSP board where the
output buffers are. Every output DSP Handle Cluster is identical to the corresponding input DSP Handle
Cluster. The two DSP Handle Clusters are internally connected. The output is an indicator. The input is a
control. For example, in the DSP Add VI, shown in Figure 1-6, Z is the DSP Handle Cluster that indicates
where to store the results. You use Z in to connect to a valid DSP Handle Cluster that you previously allocated.
Z in tells the DSP board where the results will be stored. Z out is the location where the results have already
been stored. Because Z in and Z out are the same DSP Handle Cluster, you need to free only one of them when
you want to deallocate their DSP board buffer.
from the way you would specify output data buffers for other LabVIEW VIs. DSP Handle Clusters also
represent all the output data buffers in the NI-DSP Analysis VIs. To use valid DSP Handle Clusters for the
NI-DSP VI output data buffers, you must use the DSP Allocate Memory VI to obtain the DSP Handle Clusters
before you use them. Supply all of the output DSP Handle Clusters as inputs to tell the DSP board where the
output buffers are. Every output DSP Handle Cluster is identical to the corresponding input DSP Handle
Cluster. The two DSP Handle Clusters are internally connected. The output is an indicator. The input is a
control. For example, in the DSP Add VI, shown in Figure 1-6, Z is the DSP Handle Cluster that indicates
where to store the results. You use Z in to connect to a valid DSP Handle Cluster that you previously allocated.
Z in tells the DSP board where the results will be stored. Z out is the location where the results have already
been stored. Because Z in and Z out are the same DSP Handle Cluster, you need to free only one of them when
you want to deallocate their DSP board buffer.
Figure 1-6. DSP Add VI
All of the controls and indicators in the NI-DSP Analysis VIs follow the Z in, Z out naming convention and
work in the same way as previously described in the example, except for the error in/error out cluster.
work in the same way as previously described in the example, except for the error in/error out cluster.
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Error Handling. All of the NI-DSP Analysis VIs have an error input and an error output for managing and
reporting errors. The error in/error out cluster used by the NI-DSP VIs and many other high-level I/O
operations is a cluster containing a Boolean indicating whether the data should be treated as an error, a 32-bit
error code, and a descriptive string that usually contains the name of the source of the error. The error in/error
out cluster is shown in Figure 1-7.
reporting errors. The error in/error out cluster used by the NI-DSP VIs and many other high-level I/O
operations is a cluster containing a Boolean indicating whether the data should be treated as an error, a 32-bit
error code, and a descriptive string that usually contains the name of the source of the error. The error in/error
out cluster is shown in Figure 1-7.
Figure 1-7. The error in/error out Cluster