Hello, I am hoping some of you could help me understand how best to time-synchronize the cDAQ 9189 v 20.0 and FlexLogger 2021 R2 with an external reference clock. I am using NI hardware and Flexlogger for the first time and if possible would like to avoid LabView. I would like to have 10 mu-s timing accuracy. The external reference clock outputs a variety of formats, including 10 MHz, flavors of IRIG B, PTP IEEE 1588-2008, pulses, etc. The laptop system running Flexlogger is synchronised via non-NI software PTP. In a state not corresponding to high load, measured clock drift is < 1 mu-s.I do not anticipate high loads but maybe 4 cDAQ data streams maximum <= 25kHz sampling. Would it be sufficient to synch the cDAQ via 10 MHz BNC? If so, how is that implemented, i.e., which module, and does the frequency choice limit my sampling rate? 'Where' are the timestamps for the 60sec FlexLogger files generated and would it be preferred to use timestamping on the cDAQ? As you see from my question, I am lacking a basic understanding of how these systems work together and would appreciate basic but specific suggestions. I also read a lot of whitepapers on NI (such as cdaqsynctypes). Hardware-Based IEEE 1588v2 was mentioned and I do not think my network will work with IEEE 802.1AS. Thanks for any suggestions! Kai

FlexLogger

Reference clock cDAQ 9189 and FlexLogger 2021 R2

Hello,

I am hoping some of you could help me understand how best to time-synchronize the cDAQ 9189 v 20.0 and FlexLogger 2021 R2 with an external reference clock. I am using NI hardware and Flexlogger for the first time and if possible would like to avoid LabView. I would like to have 10 mu-s timing accuracy.

The external reference clock outputs a variety of formats, including 10 MHz, flavors of IRIG B, PTP IEEE 1588-2008, pulses, etc. The laptop system running Flexlogger is synchronised via non-NI software PTP. In a state not corresponding to high load, measured clock drift is < 1 mu-s.I do not anticipate high loads but maybe 4 cDAQ data streams maximum <= 25kHz sampling.

Would it be sufficient to synch the cDAQ via 10 MHz BNC? If so, how is that implemented, i.e., which module, and does the frequency choice limit my sampling rate? 'Where' are the timestamps for the 60sec FlexLogger files generated and would it be preferred to use timestamping on the cDAQ?

As you see from my question, I am lacking a basic understanding of how these systems work together and would appreciate basic but specific suggestions. I also read a lot of whitepapers on NI (such as cdaqsynctypes). Hardware-Based IEEE 1588v2 was mentioned and I do not think my network will work with IEEE 802.1AS.

Thanks for any suggestions!

Kai