PCI-5114 clicks when the trigger is changed---is this bad?

[Karl T.]

Hi everyone,

I'm working with a PCI-5114, using several triggers in a LabVIEW program that loops every second.  In the program, I first trigger off of channel 0, then I reset the trigger to collect different information, this time triggering off of the trigger channel, and reading out channel 1.  This works, and I get the data that I want (hooray!), but every time the trigger changes (once per second), I hear a loud click from the PCI-5114.  Is this bad?  Will switching like this eventually harm my digitizer? 

If it's not bad, I'm happy to endure the clicking.  If it is bad, then I need to figure out a new way to read out my card.  

Thanks in advance!

[Brandon_B · Accepted solution]

Hello Karl,

Some scope cards, such as the PCI-5114, have active switches in them.  The noise you are hearing is the switching anytime you change your analog trigger from one channel to another.  These switches will eventually go bad after extended usage, so I highly recommend that you stop switching the analog trigger back and forth each iteration of your loop.  Once the switch goes bad, your card will have to be sent in for repair.  Instead, you may want to look into using one of the PFI lines as a trigger instead.  

Regards,

[Karl T.]

Thanks Brandon!

I went ahead and split the job between the two NI-5114's that I have, which is a little inefficient but saves wear on the switch.  I'll probably need the second card soon here, so I will go ahead and order the cable that I need to connect the PFI triggers.

Thanks again,

Karl