4.3. NetSDR Calibration Control Items
4.3.1 A/D Input Sample Rate Calibration
Purpose: Specifies the NetSDR A/D input sample rate for calibration purposes.
Control Item Code: 0x00B0
Control Item Parameter Format:
The first parameter is a 1 byte receiver channel ID. This parameter is ignored since all channels must be the same.
The following 4 byte parameter specifies the input source sample rate in Hz.
The NetSDR nominally has a sample rate of 80,000,000 Hz. This command can be used to specify the actual
sample rate so that the frequency can be set more accurately. This value is saved in the NetSDR internal memory so
does not need to be set unless a new calibration value is needed.
Note, this does not change the sample rate but is a way to tell the NetSDR what its actual sample rate is so it can
accurately set its NCO frequency.
Example, suppose the actual A/D sample rate is 80,000,123Hz.
To set the NetSDR sample rate to 80,000,123Hz.
The host sends:
[09][00] [B0][00] [00] [7B][B4][C4][04]
The Target would reply with the following:
[09][00] [B0][00] [00] [7B][B4][C4][04]
4.3.2 NetSDR DC Calibration Data
Purpose: Sets the DC offset value to be used by the A/D Converter.
Control Item Code: 0x00D0
Control Item Parameter Format:
The first parameter is a 1 byte channel ID.
Selects which channel to set.
Channel 1 ID == 0x00
Channel 2 ID == 0x02
The second parameter is a 2 byte signed 16 Bit value specifying the DC Offset. This value is saved in the NetSDR
internal memory so only needs to be changed when a new calibration value is needed.
This offset is used to reduce the spectral power at DC when an FFT is performed on the data.
Example, to set the A/D Channel 1 DC Offset to -234.
The host sends this:
[07][00] [D0][00] [00] [16] [FF]
The Target responds with:
[07][00] [D0][00] [00] [16] [FF]
Rev. 1.03 2011-11-01
22
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentarios a estos manuales