How to trigger a pulsed laser

[ksarpong]

I have written a simple labview code that is supposed to trigger an ND:YAG pulsed laser. The DAQ sends some signals which can be observed on a scope but when the DAQ is connected to the external TRIG of the laser, nothing happens; it doesn't trigger the laser. I am wondering if I am doing something wrong. Any help would be appreciated.

I have attached the code. Thanks

[santo_13]

What is the voltage level and pulse duration required for the LASER to trigger? Can you share the manual for the LASER driver or control interface?

[GerdW]

Hi ksarpong,

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@ksarpong wrote:

I have written a simple labview code that is supposed to…

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• Why is the "No. of shots" control orange? It should be a blue integer value, don't you think?
• Why is there no error handling at all? (Did you try to learn from all those DAQmx example VIs in the example finder?)
• Why do you need to create and kill the DAQmx task in each iteration of the inner loop?
• Right now there is NO WAY to set any timing for your "pulse" output! You start the task, output a TRUE, output a FALSE and kill the task AS FAST AS POSSIBLE in each iteration…
• Which (DAQ) hardware do you use?
• As asked before: which signal is required by your laser driver?

[ksarpong]

From the manual (pages 33-34), the laser requires 10-20 microsecond pulse width and 0 to +5VDC TTL signal. Interestingly, I was able to trigger (using the same code) when the signals are sent to the flashlamp trigger IN but not when it is sent to the Q-switch trigger IN. I want help to be able to trigger using the Q-switch trigger IN, that way the pulse-pulse shots are quite stable. I have attached the manual for the laser here and all that is needed are on pages 33-34. Thank you.

[ksarpong]

Interestingly, the code works when the signals are sent to the flashlamp but not when the signal is sent to the Q-switch. 

[Kevin_Price]

With only a brief look at the manual, page 34 seems to suggest that you'd want to provide precisely-timed pulse signals to BOTH the Flashlamp and Q-Switch inputs for best results.

Precise timing of 2 signals will require some kind of hardware-based timing rather than your present approach of software timing.  I would personally approach this with counter tasks, but a hardware-timed digital output task might also be a viable approach.   

What DAQ device(s) do you have available to use for this app?

-Kevin P

[ksarpong]

An image of the DAQ device I am using is attached. Thanks

[santo_13]

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@ksarpong wrote:

An image of the DAQ device I am using is attached. Thanks

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This image is not really helpful, the model of the DAQ is the information required.

[ksarpong]

M/N: USB-6003

P/N: 15442D-01L

S/N: 1F3CF06

Thanks!

[santo_13]

You got a "low-cost" DAQ, which means the features are also basic and limited. 

As per your LASER manual, you need to send 150us spaced pulses to FLASHLAMP and Q-SWITCH