Multifunction DAQ

cancel
Showing results for 
Search instead for 
Did you mean: 

RTSI PXI multiple DAQ synchronization

I am using two PXI-6133 and I would like them to trigger off of an analog signal in one of the cards. I've tried to create an RTSI cable in NI max and add both devices however when I create the cable and right click I do not have the option of adding devices. Do I simply have the wrong cards for this or am I missing some configuration step.

 

Thanks in advance.

0 Kudos
Message 1 of 4
(3,171 Views)

Hi fchacon,

 

With a PXI system you don't need to create a RTSI cable in MAX. The PXI backplane provides a trigger bus that lets you share triggers and clocks the same way RTSI did. As long as your PXI chassis is recognized in MAX and the PXI 6133's show up in the chassis you can share the trigger.

 

If both of your cards are performing acquisitions with the same rate, trigger, number of samples, etc I'd recommend channel expansion. Put the channels from both devices into a single task, and DAQmx will find an available trigger line on the PXI backplane and route automatically. Here's a great KB on channel expansion.

 

If you only want to share a trigger, and not share the same task, you can route the trigger by name. For instance, if you wanted the card in slot 2 to use one of it's analog signals as a trigger, you'd use the DAQmx Trigger VI, set it to Analog Start, and set the source as Ch0 for example. For slot 3, you could set your DAQmx Trigger VI to Digital Start and set the source as PXI1Slot2/ai/StartTrigger. DAQmx knows what routes are already in use and picks a free trigger line.

 

-Luke

0 Kudos
Message 2 of 4
(3,154 Views)

I tried routing the trigger however it does not recognize it as being a valid source. I get an error 200265 saying that the only valid options are channels which are already in the task. and then it lists out those channels which i had added to the task.

0 Kudos
Message 3 of 4
(3,137 Views)

Hi fchacon,

 

Does this KB help answer that question? There are some considerations you have to make when setting up your triggering in code:

 

http://digital.ni.com/public.nsf/allkb/6F50064F936FA29186257537005B244A?OpenDocument

Rahul B.
0 Kudos
Message 4 of 4
(3,132 Views)