HSDIO Trigger Export

[QKD]

I would like to generate a output trigger signal on PFI-1 (on any other line) when an acquisition session starts due to a pattern match.

I tried using the "ExportSignal.vi" and the "Start Trigger" signal (tried all the signals options) but it generates the signal "before" the acquisition starts.

I am recieving a serial stream and using a deserializer so I can detect the start of a frame. The start of an acquisition on pattern detection works fine but I would like to synchronize some other devices when the start pattern is detected. 

[Jordan F]

I am not sure if this is exactly what you were doing before when using the ExportSignal.vi but i would recommend to check out the "Dynamic Generation and Acquisition-Source Synchronous.vi" example in the example finder. I know that you do not want to do hardware compare (and cant with the 6562) however, it does show how to export a "data active event" to a PFI line. This data active event is a pulse that is generated as soon as the acquisition (or generation) starts. That example shows that a pulse is output on PFI1 when the HSDIO card starts generating and is externally routed to PFI2 which triggers the acquisition. So, you can try using the export signal vi and output a data active event on PFI1 to see if it triggers properly.

[QKD]

I have no problem exporting the signal and I have looked at that example (and all the other examples). The problem is there is a signal (pulse) even when the acquisition has not started. I have tried all the signal options. Based on the description of the triggers, the one that should work best is the "Reference Trigger" as it should not occur until it starts the acquisition.

(It does not start because the start pattern is not detected.)

[Jordan F]

After reviewing your code we were able to replicate the hardware setup with a pattern match trigger and watched the trigger line with an oscilloscope to see how the trigger was being sent. We found things to be working as expected with our examples, but when we were using your program we noticed 2 edges on the line (one immediate and one at our trigger). We used highlight execution in LabVIEW to see when each trigger was occurring and the first edge occurs on the niHSDIO Init Acquisition Session VI. We noticed that you had the reset device constant set to true for this VI and after changing this to be false the issue went away. The device reset is tristating the device lines and resetting the voltage level settings and is causing a glitch on the PFI line as it tristates.

Try changing this and see if you are able to eliminate the glitch!