Waveform data requirements, Understanding waveform data, Bits and bytes – Agilent Technologies N5183A MXG User Manual
Page 195
Agilent N518xA, E8663B, E44x8C, and E82x7D Signal Generators Programming Guide
185
Creating and Downloading Waveform Files
Understanding Waveform Data
Waveform Data Requirements
To be successful in downloading files, you must first create the data in the required format.
•
Signed 2’s complement
•
2- byte integer values
•
Input data range of
−32768 to 32767
•
Minimum of 60 samples per waveform (60 I and 60 Q data points)
•
Interleaved I and Q data
•
Big endian byte order
•
The same name for the marker, header, and I/Q file
This is only a requirement if you create and download a marker file and or file header, otherwise
the signal generator automatically creates the marker file and or file header using the I/Q data
file name.
NOTE
FTP can be used without programming commands to transfer files from the PC to the signal
generator or from the signal generator to the PC.
“Waveform Structure” on page 193
.
For more information on waveform data, see
“Understanding Waveform Data” on page 185
Understanding Waveform Data
The signal generator accepts binary data formatted into a binary I/Q file. This section explains the
necessary components of the binary data, which uses ones and zeros to represent a value.
Bits and Bytes
Binary data uses the base- two number system. The location of each bit within the data represents a
value that uses base two raised to a power (2
n- 1
). The exponent is n
− 1 because the first position is
zero. The first bit position, zero, is located at the far right. To find the decimal value of the binary
data, sum the value of each location:
1101 = (1
Ч 2
3
) + (1
Ч 2
2
) + (0
Ч 2
1
) + (1
Ч 2
0
)
= (1
Ч 8) + (1 Ч 4) + (0 Ч 2) + (1 Ч 1)
= 13 (decimal value)
Notice that the exponent identifies the bit position within the data, and we read the data from right
to left.
The signal generator accepts data in the form of bytes. Bytes are groups of eight bits:
01101110 = (0
Ч2
7
) + (1
Ч 2
6
) + (1
Ч 2
5
) + (0
Ч 2
4
) +(1
Ч2
3
) + (1
Ч 2
2
) + (1
Ч 2
1
) + (0
Ч 2
0
)
= 110 (decimal value)