hadware trigger to boolean

[knapkerd]

I have seen many examples for using a hardware trigger to start data acquisition, but I want to use a hardware trigger to start the recording of data to a file (acquisision has already started).  Essentially I want to take the trigger information and use it as a boolean to indicate whether I am taking data or not.  How would I impliment this?  Are there any helpful examples?

Thanks.

--Robert

[Ray.R]

Are you refering to something like what is described in this link?

http://forums.ni.com/ni/board/message?board.id=170&message.id=190267

RayR

[knapkerd]

Will the trigger outside the loop be able to trigger something inside the loop?  Lets say I have a Write to Measurement File Express VI and I want to use the trigger to create a true or false for the "enable" input to the VI.  So, if I put the hardware trigger to true, the VI will write to the file and if false, the VI will not write to a file.  I wasnt sure if a trigger outside of the loop could initiate things inside of the loop (using while loop, not for loop as in the linked example).

Sorry, but I am new to triggering.  And thanks for the quick reply.

--Robert

[Ray.R]

Unfortunately I do not have LV installed on this PC, so I couldn't open the VI.

You should be able to place the trigger within the loop.  However, be careful not to activate the writing to the file unnecessarily at each iteration. 😉

A proper State Machine or Event Structure architecture would assure you to accomplish that.  Or at minimum, a Case Structure which selects (activates) the appropriate trigger to when writing to the file is appropriate.

Short answer:  yes, you should be able to trigger within the loop.

RayR

[knapkerd]

I will work on that then.  Thanks for your help.

--Robert

[Ray.R]

Let me know how it goes. 

RayR