Hello, I am using a DAQ-mx (NI USB-6211) and would like to use it to generate a digital modulated pulse which is triggered by an analog input signal. The input signal is an analog modulated square pulse which is nearly periodic. This is due to my set up and I can do nothing with it. I would like to use the front edge of this signal to trigger the generation of a modulated pulse digital signal (0-5 V). My problem is summarized on the figure given in attachment. I would like to also have the possibility to configure The "delay" and "TAU_LED" duration while the VI is working. I have been looking at several NI instrument examples of counter generation, AI/AO generation but did not manage to solve my problem. Does anybody have an idea of how to start with my problem? are there any example VI that I could start modifying? Thanks in advance, Grégory

Hi Gregory, Sorry I forgot to mention: the Initial Delay is only applicable on the first pulse of a retriggerable generation. Every subsequent pulse will use the Low Time as the Initial Delay. I'll agree the behavior is not very intuitive (our more recent X Series boards actually support an Enable Initial Delay on Retrigger Property), but it is described in this KnowledgeBase, and should also be mentioned in the DAQmx Help. Since you're just generating a single pulse, I would recommend simply connecting the Initial Delay and the Low Time inputs to the same value so every pulse will be delayed by the same amount. Continuous Counter Output tasks currently support DAQmx Write. However, finite or single pulse generations do not. However, you should still be able to get the behavior you need with a DAQmx Property Node. The current workaround on E/M series is the following: Again this isn't the most intuitive, but I have verified that it works on my 6210. After writing a new value in software the pulse will be updated on the 2nd trigger. Attached is the code saved in LV8.2. Best Regards,

Multifunction DAQ

[debutant on Labview 8.5] Generation of a digital modulated square pulse triggered by an almost periodic analog modulated square pulse

Solved!

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Hello,

Thank you John! it works perfectly now.

Best regards,

Grégory

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Multifunction DAQ

[debutant on Labview 8.5] Generation of a digital modulated square pulse triggered by an almost periodic analog modulated square pulse

Re: [debutant on Labview 8.5] Generation of a digital modulated square pulse triggered by an almost periodic analog modulated square pulse