digital edge timestamp ni9403

[dpom]

Good morning all,

I am relatively new to labview and have the following problem that I am trying to solve which is stumping me at the moment:

I have requirements to test the time (in milliseconds) from physically touching a touch screen to receiving a specific packet on the other end of a test system. I currently have a momentary switch wired into a ni-9403 module to capture the time when the touchscreen is physically touched. Capturing of the packet timestamp will be handled by wireshark which will be running on the same computer as labview. The expected timeframe to receive the packet is under 20ms, so there is not much room for error with the timestamp. Labview is prioritized on 2 cores of the computer and wireshark gets a single core, the 4th core is assigned to the os. The system clock of the pc will be utilized for the timestamp to compare the 2 timestamps.

For the labview portion, the scope only consists of capturing the timestamp (including milliseconds) for when the momentary switch triggers (a rising edge digital signal coming from the ni 9403 daq) and logging the timestamp to a file. I only need the timestamp for the first rising edge seen, after that the vi can terminate. The desired output file would be a csv file and to the screen. The timestamp has to be accurate within 1-2ms.

I have found plenty of examples on exporting analog waveforms with timestamps to tdms, but i have not yet found an example on how to achieve this with a triggered digital input (and i have been searching the internet for a week on examples related to timing digital signals/edges/state change detection timestamp/writing digital signals to tdms, etc). I figured I would have at least found an example related to timestamping/recording the use of a emergency stop button. It doesnt make it any easier that the 9403 does not support state change detection in its current version.

Currently I am running lv2013 and daqmx 9.7.5

Could anyone point me towards an example or help me figure this one out? any help would be greatly appreciated,

Stephen

[Esteban.R]

Hi dpom

I have not fully understood your question, you want to create a digital waveform signal with the timestamp and log the data.

What exactly do you want to trigger log the data or a process?

If you mean trigger the process of logging we should be able to do this programmatically

Could you provide me a little more details and if it is possible point me to the examples that you have find with analog tasks in order to understand what exactly you want to do

Regards

Esteban R.