Agilent Technologies DSO6014A/L, Programmer'S Reference Manual

Page: 617 / 634

Programming Examples
9
Agilent 6000 Series Oscilloscopes Programmer's Reference 617
VisaComError:
MsgBox "VISA COM Error:" + Err.Description
End Sub
'
' Capture
' -------------------------------------------------------------------
' We will capture the waveform using the digitize command.
' -------------------------------------------------------------------
Private Sub Capture()
On Error GoTo VisaComError
' AQUIRE_TYPE - Sets the acquisition mode, which can be NORMAL,
' PEAK, or AVERAGE.
myScope.WriteString ":ACQUIRE:TYPE NORMAL"
' AQUIRE_COMPLETE - Specifies the minimum completion criteria for
' an acquisition. The parameter determines the percentage of time
' buckets needed to be "full" before an acquisition is considered
' to be complete.
myScope.WriteString ":ACQUIRE:COMPLETE 100"
' DIGITIZE - Used to acquire the waveform data for transfer over
' the interface. Sending this command causes an acquisition to
' take place with the resulting data being placed in the buffer.
'
' NOTE! The DIGITIZE command is highly recommended for triggering
' modes other than SINGLE. This ensures that sufficient data is
' available for measurement. If DIGITIZE is used with single mode,
' the completion criteria may never be met. The number of points
' gathered in Single mode is related to the sweep speed, memory
' depth, and maximum sample rate. For example, take an oscilloscope
' with a 1000-point memory, a sweep speed of 10 us/div (100 us
' total time across the screen), and a 20 MSa/s maximum sample rate.
' 1000 divided by 100 us equals 10 MSa/s. Because this number is
' less than or equal to the maximum sample rate, the full 1000 points
' will be digitized in a single acquisition. Now, use 1 us/div
' (10 us across the screen). 1000 divided by 10 us equals 100 MSa/s;
' because this is greater than the maximum sample rate by 5 times,
' only 400 points (or 1/5 the points) can be gathered on a single
' trigger. Keep in mind when the oscilloscope is running,
' communication with the computer interrupts data acquisition.
' Setting up the oscilloscope over the bus causes the data buffers
' to be cleared and internal hardware to be reconfigured. If a
' measurement is immediately requested, there may have not been
' enough time for the data acquisition process to collect data,
' and the results may not be accurate. An error value of 9.9E+37
' may be returned over the bus in this situation.
'
myScope.WriteString ":DIGITIZE CHAN1"
Exit Sub