How to set multichannel sapling rate and trigger in SignalExpress

[xiao@ou]

Hardware: cDAQ-9174 (4 slot USB);          NI 9215 with BNC 4 ch +10v - -10v, 100kS/s 

Project description: we had run DAQ with dev1-ai0 at 100k sampling rate and worked fine.

Now we need add another signal at dev1-ai1 with lower sampling rate (say 50kS/s) and need set triggers work like:

ai1 will be triggered at signal level 2.0 V then delay 0.5s to trigger (recorded) ai0.

In future, we may need another signal to ai2 with same sampling rate as ai0 and want it be triggered at same time as ai0.

Checked NI KB, one article ("How can I Acquire and record pre-trigger samples in SignalExpress") mentioned “reference trigger” and “record option”, so I try use “reference trigger” for ai1 and use “record option” for ai0.  But my SE (come with hardware) do not let me set reference trigger (trigger type selection was disabled) and also I cannot set trigger for each channel, acquisition mode selection work for all channels.

Please help:

How to set up sampling rate for each channel?

Is it possible to set trigger in the way mentioned above for each channel? If so how? If not, what is possible way?

Do all data acquired go to one data file? Or possible to separate them?

Thanks

[NathanS]

Hi Xiao@ou,

I am wondering, why do you need ai1 to sample at 50kS/s? Is there a problem with sampling it at the same rate as ai0?

Unfortunately, SignalExpress may not be capable of doing all the customizations your application requires. You may want to consider using LabVIEw in order to have more control.

Regards,