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6.
Set the synchronization type of the Start Trigger slaves at
DAQmx Trigger»Advanced»
Synchronization»Synchronization Type
to Slave and that of the Master to Master.
7.
Query
DAQmx Timing»More»Synchronization Pulse»Synchronization Time
on all
modules being synchronized, choose the maximum value and set that as the
DAQmx
Timing»More»Synchronization Pulse»Minimum Delay To Start
on the module from
which the synchronization pulse originates.
8.
Commit all of the sync pulse slave module tasks using the DAQmxTaskControl
VI/Function. This sets them up to expect the sync pulse from the master.
9.
Commit the sync pulse master module task using the DAQmxTaskControl VI/Function.
This will issue the sync pulse.
10. Start all of the start trigger slave module tasks. This sets them up to expect the start trigger
from the master.
11. Start the start trigger master module task. You can now acquire data.
Tip
Consider using a Multi-Device task when synchronizing multiple devices at the
same rate.
Tip
You can find example VIs in the NI Example Finder. Select
Help»Find
Examples
to launch the NI Example Finder.
Consider the following caveat to using Reference Clock Synchronization:
•
The PXIe-4340 automatically compensates for its filter group delay. However, some other
device families do not compensate for their filter delay. In this case, manually compensate
for group delay in the waveforms when you synchronize between device families if this
level of synchronization is required for your application.
Timing Engines and DSP Streams
This section gives an overview of the internal implementation of the PXIe-4340 and how the
module can be configured. The use of NI-DAQmx software allows you to easily configure the
PXIe-4340 without you understanding the internal workings of the device.
Timing Engines
When you create a task in software, that software task interacts with one or more timing engines
in the PXIe-4340. There are a total of four timing engines in hardware that can be operated
simultaneously. Each of these timing engines can have individualized configuration settings for
timing, triggering, and the sample mode. Depending on the sample mode selected, the timing
engine will use either a Buffered Mode or Hardware-Timed Single Point DSP stream.