National Instruments NI PXI-5922, Руководство пользователя, Страница: 14 / 21

14 | ni.com | NI 5922 Calibration Procedure
4. Call
niScope_ConfigureHorizontalTiming
(niScope Configure Horizontal
Timing VI) with the following parameters:
•
minSampleRate :
1,000,000
• minNumPts :
100,000
• refPosition :
50.0
• numRecords :
1
• enforceRealtime :
NISCOPE_VAL_TRUE
5. Call
niScope_InitiateAcquisition
. (niScope Initiate Acquisition VI) with the
following parameter:
•
vi : The instrument handle you obtained from
niScope_init
6. Call
niScope_FetchMeasurement
(niScope Fetch Measurement VI) with the
following parameters:
•
channelList :
"0"
• timeout :
1.0
• scalarMeasFunction :
NISCOPE_VAL_DC_ESTIMATE
7. Call
niScope_ConfigureChanCharacteristics
(niScope Configure Chan
Characteristics VI) with the following parameters:
•
channelList :
"0"
• inputImpedance :
NISCOPE_VAL_1_MEG_OHM
• maxInputFrequency :
0
8. Call
niScope_InitiateAcquisition
(niScope Initiate Acquisition VI) with the
following parameter:
•
vi : The instrument handle you obtained from
niScope_init
9. Call
niScope_FetchMeasurement
(niScope Fetch Measurement VI) with the
following parameters:
•
channelList :
"0"
• timeout :
1.0
• scalarMeasFunction :
NISCOPE_VAL_DC_ESTIMATE
10. Calculate the bias current using the following formula:
where a = the voltage measured in step 6
b = the voltage measured in step 9
1,000,000 is the NI 5922 impedance in ohms
Compare the resulting bias current to the value listed in the Calibration Test Limits column
or the Published Specifications column in Table 5. If the result is less than the selected test
limit, the device has passed this portion of the verification.
Bias Current
a b
–
1,000,000
------------------------ =