Programming Examples | 9 |
VisaComError:
MsgBox "VISA COM Error:" + vbCrLf + 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
'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
Agilent InfiniiVision 5000 Series Oscilloscopes Programmer's Reference | 581 |
