Does the external trigger of the 5152 count as a second channel?

[jamoore84]

Hi everyone,

The PXI-5152 digitizer is listed as providing a 2GS/s sampling rate (TIS) for one channel only.  My question is whether or not the External Trigger channel counts as a "second channel" when used during data acquisition.  If so, does this cause the maximum acheivable sampling rate to drop to 1GS/s for my data channel (CH 0)?

My experience has been that this is the case, but I lack a smoking gun which explicitly states this.  When I use the external trigger to control data acquisition on Channel 0, I'm only ever able to acheive 1GS/s.  Am I making a mistake?

I was hoping that the trigger port would act as a simple comparator.  If not, does this imply that the external trigger channel is being sampled at 1GS/s? 

Many thanks,

Jimmy

[Jennifer O]

Hi Jimmy,

The External Trigger is not digitized and therefore is not a second channel. It is appropriate to consider it like a comparator.  It can be used as an analog trigger source for the TIS acquisition on channel 0 to achieve 1 channel at 2 GS/s.  I am not sure why you are only achieving 1 GS/s.

I recommend starting with an example program such as "Configured Acquisition".  You can navigate to this example through the Example Finder, or by using your Start Menu and navigating to All Programs>>National Instruments>>NI-SCOPE>>Examples.  Select your preferred programming environment such as LabVIEW and locate Configured Acquisition.

Once you have the example open try the following settings to achieve 2GS/s on ch0 triggered from the external trigger input. Set the sampling rate to 2GS/s, the channel to 0, check "TIS Enabled", and ensure that Enforce Realtime is also checked.  Set the trigger type to Edge, and the trigger source to the External Trigger.

- Jennifer O.

Product Support Engineer - High Speed Digitizers