Agilent Technologies 4155C, User Manual

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Agilent 4155C/4156C VXIplug&play Driver User’s Guide, Edition 4 3-7
Programming Examples for Visual Basic Users
High-Speed Spot Measurements
High-Speed Spot Measurements
This section explains example subprograms that enable/disable measurement
channels (perform_meas), perform high speed spot measurement (spot_meas), and
display measurement result data (display_data). This example measures MOSFET
drain current.
Table 3-2 High-Speed Spot Measurement Example
Sub perform_meas(vi As Long, ret As Long) ’1
Dim pins(4) As Long ’SMU port numbers ’3
pins(0) = 1 ’SMU1: drain
pins(1) = 2 ’SMU2: gate
pins(2) = 3 ’SMU3: source
pins(3) = 4 ’SMU4: substrate
ret = hp4156b_setSwitch(vi, pins(3), 1) ’9
ret = hp4156b_setSwitch(vi, pins(2), 1)
ret = hp4156b_setSwitch(vi, pins(1), 1)
ret = hp4156b_setSwitch(vi, pins(0), 1)
check_err vi, ret
’13
spot_meas vi, ret, pins() ’15
ret = hp4156b_setSwitch(vi, hp4156b_CH_ALL, 0) ’17
check_err vi, ret
End Sub ’20
Line Description
1 Beginning of the perform_meas subprogram.
3 to 7 Declares variables, and defines the value.
9 to 12 Enables measurement channels.
15 Calls the spot_meas subprogram (next page) to perform spot
measurement.
17 Disables measurement channels.
13 and 18 Calls the check_err subprogram (shown in Table 3-1) to check if
an error status is returned for the previous line.
20 End of the perform_meas subprogram.