AWG - update time?

[the_desperate_one]

Hi,

I plan to operate a Laser whose output power is controlled by a PWM signal between 5kHz-100kHz. Besides continuous operation at a fixed PWM signal I want to implement a feedback loop to stabilize the output power. Hence, I need to continuously update the PWM signal applied to the Laser. I thought of using the arbitrary waveform generator to generate the pwm signal.

My question is the following: If I operate the AnalogDiscovery2 and set a new arbitrary waveform/PWM signal, do you know how long it takes before the AD2 actually puts this waveform on the output?

Thank you very much for your help

[zygot]

I don't have a specific time  for what you want because, given that this is a USB device operating in a PC OS with other applications running, no one can guarantee latency. You situation is dire if you want to have a feedback loop that does anything approaching "real time" (just for arguments sake let's day real-time units are milliseconds). 

What you want to do, if I understand you correctly, could be done using an ordinary FPGA board with all of your loopback algorithm implemented in an HDL perhaps with a PID.

[jpeyron]

Hi @the_desperate_one,

Welcome to the Digilent forums!

I moved the thread to a section where the AD2/Waveforms engineers look.

best regards,

Jon

[attila]

Hi @the_desperate_one

As previously mentioned there is not guaranteed latency.

In this simple example the AWG duty is adjusted 100 times which takes on my machine 100-500ms.
One adjustment usually takes 1-10ms, depending on USB and available system resource.
You would probably want to make some measurement, like with Scope and based on this to adjust the output. This will take additional time.