Flexlogger Automation - output channel update rate?

[mnugent]

I know FlexLogger is not intended to be deterministic, but about how fast can we expect to write to via an output channel via Python or LabVIEW automation?

My testing with writing square waveforms to a FlexLogger output channel via LabVIEW automation and then viewing the output on an o-scope implies we start to loose accuracy around 10hz.

For example, with a 0.5s on and 0.5s off square wave, the o-scope shows most of the pulses at 0.5s, but a few are closer to 0.4s or 0.6s.

As a second example, testing a 0.1s square wave, I start to see missed pulses on the o-scope.

Is this update rate expected? Is there a way to adjust an .ini or .cfg file parameter to increase this speed?

[ZYOng]

The maximum update rate is largely affected by the latency of your DAQ device.

You will get a faster response using PCI/PXI compared to USB or Ethernet cDAQ.

Reference: Instrument Bus Performance – Making Sense of Competing Bus Technologies for Instrument Control

[mnugent]

Thank you for that answer about hardware rates. My question is not related to the hardware rate of the device/bus, but rather the software rate of the Automation API between FlexLogger and Python/LabVIEW.

[Brad]

Using the API to set output channels in FlexLogger is highly SW timed and roughly 100ms accuracy seems reasonable and expected. Hope this helps and let us know if you need more info.

Thanks,

Brad