how to set trigger options in ps 3000

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how to set trigger options in ps 3000

Post by Guest » Thu May 10, 2007 8:23 am

HI,
The API provided with the ps3000 series has the ps3000_set_trigger() function. Can you please enlighten on how to set the "threshold" and "delay" parameters? is the threshold in mV or V setting?

markB
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Post by markB » Thu May 10, 2007 2:41 pm

The PS3000 manual states:
the threshold for the trigger event. This is scaled in 16-bit ADC counts at the currently selected range. If an external trigger is enabled the range is fixed at +/-20V.
threshold (16 bit ADC counts) = threshold (mV) * 32767 / inputRange(mV)

Therefore, if you have the 1V range selected and you want to trigger at 100mV the threshold will be:

100 * 32768 / 1000 = 3277 16 bit ADC counts
Regards

Mark

Guest

Re:

Post by Guest » Fri May 11, 2007 1:34 am

Hi, thanks for the reply.

How about the parameter on delay? I am using the example program streamingtest in C++ with the user interface. How should i determine what to be entered in the delay column?

Thanks and regards
Keeve

markB
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Post by markB » Mon May 14, 2007 8:35 am

Again, quoting the manual:
delay, specifies the delay, as a percentage of the requested number of data points, between the trigger event and the start of the block. It should be in the range -100% to +100%. Thus, 0% means that the trigger event is at the first data value in the block, and -50% means that it is in the middle of the block. If you wish to specify the delay as a floating-point value, use ps3000_set_trigger2() instead.
Regards

Mark

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