Scale of Frame in RealTime Mode

I am using bbFetchRealTimeFrame() to retrieve a sweep and a frame.

In my case ‘frameWidth’ is 1/4 of the number of points in the sweep. ‘frameHeight’ is reported as 256. I have checked that if I add up all 256 height bins for each width, I get ‘1’ as expected.

As I called bbConfigureRealTime() with frameScale = 100, I presume each of the 256 height bins is 100/256 = 0.390625dB wide. But what is the absolute value of each bin in dBm? Is the top bin related to the reference level?

Hi Andy,

The frame scale represents the total height of the real-time frame in dB. For example, with a frame scale of 100, a frame column will represent amplitudes between the reference level and the (reference level – 100).

Regards,
A.J.

A.J.

Thanks for that answer. So I can calculate the power in each bin knowing the reference level.

In my sweep the resolution bandwidth is ~20kHz. As frameWidth is 1/4 of the number of points in the sweep is the resolution bandwidth in the frame 80kHz?

Regards
Andy

Hi Andy,

Actually what we do is,
For each column where the sweep size is substantially larger than the max image width (1024), we divide by an integer(n) number, and plot an ‘n’ points on that column.

Regards,
A.J.

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