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To trigger a pulse at the natural zeroes of a sine wave

How do you trigger a pulse at the natural zeroes of a sine wave ?I am new to this.Please guide.
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There is a way to do this, but I don't know what kind of hardware that you have. With an E-series data acquisition board, such as the 6070E, you can set up an analog acquisition to trigger on a falling or rising signal at 0 volts. This "trigger" can then be routed to a counter, which can generate a pulse when this trigger occurs. That should accomplish the task!

Let me know if you need more information.

Mark
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Hallo,

do you have an example for this?

i also would like to trigger a signal on rising of a sine wave. i have a pci-6115 and a bnc-2110.

Regards from Germany/Hamburg

Cristian
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Hello Cristian,

There are a couple shipping examples that should help get you started on this application.  The first is the Acq&Graph Voltage-Int Clk-HW Trig Restarts VI which creates an analog task that will trigger at a specific voltage level and slope.  This task is somewhat limited by time as in order for it to retrigger that task has to be stopped and restarted, this generally takes a few ms.  If a trigger occurs during this time, it will be missed. 

Another VI that you can refer to is the Gen Dig Pulse-Retriggerable VI, this VI generates a pulse when trigger.  The counter task must use a digital trigger, the AnalogComparisonEvent signal is the output of the analog trigger circuit and is a digital signal.  You have to right click on the Terminal I/O control and select I/O Name Filtering to Include the Advanced Terminals to see this terminal.   This will trigger the pulse each time your analog input task sees an analog trigger.

Post again if you have any further questions!

Micaela N
National Instruments
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