API 3.0.5 and using saConfigSweepCoupling

[adixmasz]

Hello,
I created Labview drivers for Spectrum Analyzer USB-SA44B, I used API (version 3.0.5). Everything works fine, but I have a few questions about this API.

First question ( Sweep Mode),
I set RBW and VBW by saConfigSweepCoupling function. Can API change RBW or VBW without informing user? Can You guarantee me that when I set for example RBW=VBW=100, span = 3GHz, center = 2GHz the device will use this parameters? I would like to change units from dBm to dBm/square root(Hz) so I must be sure about value of RBW.

Second question,
I found only a few versions of API. I used the latest version, but I would like to use older version of this software.
Where can I find older versions of API?

Best regards,
Adrian

[Andrew]

Hello Adrian,

No, the API will not change RBW or VBW (when using non-native RBWs) but the API expects that the user will set reasonable values and can fail if the values create an undesirable sweep. The sweep configuration you listed will result in a 90+ million point sweep, which will likely cause the system to run out of memory attempting to allocate the memory for that size of sweep. For multi-GHz spans, considers RBWs like 30kHz or 100kHz. A good estimate for the size of the sweep to be returned is 3 * (span / rbw) for non-native RBWs. If you use the Native RBW settings, there are fixed RBW values that your selection will be clamped to.

If you need an earlier API version, email me at aj@signalhound.com and tell me which device and version you are looking for.

Regards,
A.J.

[adixmasz]

Thank you for fast reply, it was very helpful.

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