Acquire Analog Input Data with a Digital Trigger and External Scan Clock

This VI retrieves the specified amount of data from one or more analog input channels when a digital start trigger, digital stop trigger, or digital start and stop trigger, occur. This VI uses an external scan clock to continually retrieve data from one or more analog input channels. This VI will only work on devices where you can externally connect a scan clock signal. This is a buffered acquisition, meaning that the data are stored in an intermediate memory buffer after they are acquired from the DAQ board. When the pretrigger scans is set to 0, you must set "choose trigger type" to START OR STOP TRIGGER (and use a start trigger). Your start trigger will then start your DAQ board and acquisition into a buffer to be read by LabVIEW. When the pretrigger scans is set to greater than 1, you can set "choose trigger type" to START OR STOP TRIGGER (and use a stop trigger) or START & STOP TRIGGER (and use both). If you use only the stop trigger, a software strobe starts your DAQ board and your stop trigger will determine when data are acquired into a buffer to be read by LabVIEW. If you use a start and stop trigger, your start trigger will start the DAQ board, but your stop trigger will determine when data are acquired into a buffer to be read by LabVIEW. In either case, your pretrigger scans will be the number of scans to acquire before the stop trigger occurs. The rest of the number of scans to acquire will be after the stop trigger. Data are retrieved from that buffer and displayed after the appropriate amount (before and after the stop trigger) have been acquired. The vertical cursor on the graph indicates where the trigger occurred. For simplicity, this VI uses AI Start.vi to configure the scan clock. However, for different types of connections on the E-series devices (other than the default), a clock source string specification is necessary. For this you would need to expand AI Start.vi into its Advanced subVIs.

Use this VI to wait for a digital trigger while supplying your own scan clock, acquiring a relatively small amount of data (it must fit in the memory available), where each point does not need to be viewed or processed while it is being acquired.

NOTE: See the ReadMe file for important Instructions, Key Parameters, and I/OConnections.

Requirements

Filename: 1208.zip

Software Requirements

Application Software: LabVIEW Full Development System 5.0.1
Language(s): LabVIEW

Hardware Requirements

Hardware Group: Multifunction DAQ (MIO)
Driver: Traditional NI-DAQ (Legacy) 6.7.0

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