external trigger with cDAQ-9172

[Marie-Andree]

Hi,

I would like to synchronize my data collection between my EMG system (Delsys Myomonitor) and  my VI in LabVIEW. I have a trigger module (Delsys) and would like to use it to start my data collection in both systems. I have a NI cDAQ-9172.  Is there any ways I could start the data acquisition in LabVIEW?

Thanks

[John_P1]

Which modules are you using in your 9172?

Any DI module with 8 lines or less can be used to route trigger signals if placed in slots 5 or 6 (e.g. 9401 or 9402).  Alternatively, if you are using a 9205 or 9206 you may use the PFI to route the trigger signal from any slot in the 9172.

Which modules are you trying to synchroinze?  The 24-bit C Series modules use Delta-Sigma converters which have special synchronization considerations.

Best Regards,

[Ted H.]

Could someone provide an example block diagram showing use of the 9205 PFI as a trigger input?  Also if a special setup in MAX is needed, that would be helpful to show too.

[John_P1]

Hi Ted,

Assuming you're using a cDAQ chassis, the example is pretty straightforward:

In the above example, the analog input task will acquire a user-defined number of samples at a user-defined rate starting on the rising edge of a TTL signal connected to the 9205's PFI line.  No additional MAX setup is required.

Best Regards,

[Ted H.]

This was helpful - thanks for clarifying!