smSyncErr errors suddenly with SM200C

We’ve recently been retooling a custom application and are now seeing smSyncErr frequently when we never saw them before.

We are currently only interested in sweep mode, and the big change is that we used to configure our SM200C using smSetSweepCenterSpan:
smSetSweepSpeed(this_device, sweepSpeed);
smSetSweepCenterSpan(this_device, (double)this_fftSweepCenterFrequency, (double)this_fftSweepFrequencySpan);
smSetSweepDetector(this_device, smDetectorAverage, smVideoPower);
smSetSweepScale(this_device, smScaleLog);
smSetSweepWindow(this_device, smWindowBlackman);
smSetSweepSpurReject(this_device, smFalse);
smSetAttenuator(this_device, -1/*auto*/);
smSetPreselector(this_device, smFalse);
smSetReference(this_device, smReferenceUseInternal);

But now want to set it via smSetSweepStartStop/smSetSweepCoupling:
smSetSweepCoupling(this_device, (double)this_rbw, (double)this_vbw, (double)this_period);
smSetSweepStartStop(this_device, (double)this_startFrequency, (double)this_stopFrequency);
smSetSweepDetector(this_device, smDetectorAverage, smVideoPower);
smSetSweepScale(this_device, smScaleLog);
smSetSweepWindow(this_device, smWindowBlackman);
smSetSweepSpurReject(this_device, smFalse);
smSetAttenuator(this_device, -1/*auto*/);
smSetPreselector(this_device, smFalse);
smSetReference(this_device, smReferenceUseInternal);

I am curious, is it possible that depending on the values we choose, that it is occasionally missing an FFT that it is expecting causing the system to have an error? I am not sure any other reason why the change from one configuration to the other would introduce this error.

Thank you for bringing this to our attention. I will alert our software team to this issue, and see if they can duplicate it.

jmatusiak,

Depending on the settings you are using, it can affect how much data is being transferred, how much processing is occurring, among other things. This can affect the stability of the data link. That being said, sweeps should be fairly stable for most configurations. I would like to learn more about your configuration and PC setup. Can you email me at aj@signalhound.com with the following information,
– your PC make/model/CPU
– your operating system
– what kind of SFP+ adapter/card you are using
– What values you are passing to these functions.

I look forward to your response.

Andrew

Andrew and Justin, thank you for the quick responses. The software guys working on this piece of code realized they had numerous issues that needed to be addressed, so they are fixing those before we bug you further. If that doesn’t seem to help, I will certainly email you with the details. Thanks folks!

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