Measuring time delay between Arduino Uno and Labview

[optics22]

Hello,

I am very new to the community so please forgive me if my question is trivial. 

I am a University researcher and I have been given the task to measure the time delay between labview and an Arduino Uno. The problem is that we are controlling an Arduino Uno board with labiew and want to measure the time delay that it takes for the input information via labview to be carried out on the Arudino Uno. I have an oscilloscope in my possession as well but am still not sure how I should go about testing this. If any of you have an idea of a good place to start measuring this time delay please let me know.  

Regards,

Optics22

[RTSLVU]

Now I am guessing you are setting one of the Arduino DIO's to change states for this test

Well I would plug your scope into LabVIEW using whatever interface (GPIB,LXI,USB,Etc.) that you prefer.

Then setup the scope to single acquisition with say 20% pre-trigger, arm the trigger, send a VISA bus trigger command at the same time as you send the command to the Arduino.

The time between the trigger point and the DIO changing state is the value you are looking for.

[Michael_78]

That seems like a good idea, but it will include latency of the command to the scope too. You could try several methods and repeat each method many times to get closer to the mean time. Another method would be to send the device a digital output On followed by immediate Off and measure the pulse width. Divide it by 2 to get an idea of 1 way timing.  The time will likely always include some jitter from windows, the usb latency and maybe from the uno too (Depending on the firmware running).  This will be an interesting test, maybe post some results when you have them.