Data Conversion
Data sent from the oscilloscope is raw data and must be scaled for useful
interpretation. The values used to interpret the data are the X and Y
references, X and Y origins, and X and Y increments. These values are read
from the waveform preamble (see the PREamble command) or by the
queries of these values.
Conversion from Data Value to Voltage
The formula to convert a data value returned by the instrument to a voltage
is:
voltage = [(data value - yreference) * yincrement] + yorigin
Conversion from Data Value to Time
The time value of a data point can be determined by the position of the data
point. As an example, the third data point sent with XORIGIN = 16ns,
XREFERENCE = 0 and XINCREMENT = 2ns. Using the formula:
time = [(data point number - xreference) * xincrement] + xorigin
would result in the following calculation:
time = [(3 - 0) * 2ns] + 16ns = 22ns.
Conversion from Data Value to Trigger Point
The trigger data point can be determined by calculating the closest data point
to time 0.
WAVeform Subsystem
Data Conversion
35-6