Synchronize Triggers for both digital and analog signals with BNC 2110

[gx_cully]

Hi all

I have a voltage signal in the analog section of my BNC 2110, I want to connect my digital camera (Infinity 2) to the digital section of the BNC 2110 and have it to trigger with the analog trigger (set up for the voltage signal). In MAX it seems as though I can not make a combined analog and digital task, is there any way around this??

Im using a PCI 6133 board.

Thanks,

Greg 

[John_P1]

Hi Greg,

It's true that the analog and digital outputs must be in seperate tasks--this is true for all of our DAQ devices.  To synchronize the two tasks, you have the following options:

1.  Share a common sample clock between the tasks.

2. Share a timebase and start trigger between the two tasks.   This would allow you to update at different rates.

The first option is a bit more straightforward.   Here is an example written for M series devices that should also apply to your 6133 that implements this behavior.  I hope this helps, don'thesitate to let me know if you have any questions.

-John

[henry Henry]

Hi John,

Sorry to disturb you. Now I have 2 analogue trigger sources and I want to use the BNC-2110 to convert these 2 signals to digital signals before they are inputed to the LabVIEW. But the thing is when I try to use the DAQ assistant to sample these 2 signals seperately, one daq assistant will but the other one will pup up error. I know this is because the sample channels share one common clock so I can't perform tasks at one time. But when I try to sample them in one DAQ assistant, I failed to seperate the 2 signals. Can you tell me hoe should I do to read the 2 analogue signals seperately?

In addition, I noticed there is TRIGGER/COUNTER in the BNC-2110 board, can you tell me how can I configure in the LabVIEW code so that I can use that feature?

Thanks very much for your help!

Regards,

Henry

[Renée]

Henry,

You can only have one Analog Input Task at a time for a particular device, which is why you saw that error when trying to run multiple DAQ Assistants at the same time. You can also only have one sample rate per task, so the best option, if you're going to use the DAQ Assistant, would be to sample both channels at the faster of the two rates, and then disregard the data that you do not want.

If you need more help, can you give me more information about your project?

For the BNC-2011, this Knowledge Base is quite useful is figuring out which lines you will need to access:

http://ae.natinst.com/public.nsf/web/searchinternal/5b4d23831c6a8c2d86257354004de008?OpenDocument

[henry Henry]

Hi Renée,

Thanks for your reply.

My project is to use 2 GPS receivers to make the synchronization of 2 measurements. As you know, the GPS receiver will generate the Pulse Per Second signal and I will use the rising edge of the PPS to trigger the measurement to start. And in this way, the 2 measurements are synchronized.

As the PPS generated by the GPS is an analogue signal and I have to convert it to digital signal before the LabVIEW can process it, right? And currently I am trying to convert the 2 PPS signals to digital signals. And then I want to use the LabVIEW to do the measurements only at the rising edge of the signal.

But now the thing is I cannot convert the 2 PPS seperately as you have mentioned, I can only sample them both by using DAQ Assistant. But in this way, how can I seperate them into 2 parts? Or is there any other way to do this? Oh, and I can't open the website you gave me. Can you post it again? 

Thanks very much for your help!

Regards,

Henry

[henry Henry]

Hi Renée,

Sorry to bother you again. I just noticed that in the BNC-2110 board, there are trigger connectors PFI1 and PFI2. Can you tell me how to use these 2 connectors? I think maybe that that will work.

Thanks very much for your help!

Regards.

Henry

[Renée]

Henry,

It looks like your questions were answered here:

http://forums.ni.com/t5/LabVIEW/how-to-trigger-from-analog-input-channel/td-p/714526