National Instruments NI PXI-5122 Manual

CALIBRATION PROCEDURE
NI 5122/5124/5142
This document contains information for calibrating NI 5122/5124/5142 high-speed digitizers.
For more information on calibration, visit ni.com/calibration.
Contents
Software Requirements............................................................................................................. 1
Documentation Requirements .................................................................................................. 2
Password .................................................................................................................................. 2
Calibration Interval................................................................................................................... 3
Test Equipment......................................................................................................................... 3
Test Conditions......................................................................................................................... 3
Calibration Procedures ............................................................................................................. 4
Initial Setup....................................................................................................................... 4
Self-Calibration ................................................................................................................4
MAX......................................................................................................................... 4
NI-SCOPE Soft Front Panel ..................................................................................... 5
NI-SCOPE ................................................................................................................ 5
Verification ....................................................................................................................... 5
Vertical Offset and Vertical Gain Accuracy............................................................. 6
Programmable Vertical Offset Accuracy ................................................................. 17
Timing Accuracy ...................................................................................................... 22
Bandwidth and Flatness............................................................................................ 26
Trigger Sensitivity .................................................................................................... 34
Adjustment........................................................................................................................ 39
Appendix A: Calibration Options............................................................................................. 42
Complete Calibration........................................................................................................ 43
Optional Calibration ......................................................................................................... 43
Appendix B: Calibration Utilities............................................................................................. 45
MAX................................................................................................................................. 45
NI-SCOPE ........................................................................................................................45
Worldwide Support and Services ............................................................................................. 45
Software Requirements
Calibrating the NI 5122/5124/5142 requires installing NI-SCOPE on the calibration system.
Refer to Table 1 for the hardware-specific version to use with your device. You can download
the NI-SCOPE instrument driver from the Instrument Driver Network Web site at ni.com/
idnet. NI-SCOPE supports programming a Self-Calibration and an External Calibration in the
LabVIEW and C application development environments (ADEs). When you install NI- SCOPE,
you only need to install support for the ADE that you intend to use.

2|ni.com |NI 5122/5124/5142 Calibration Procedure
LabVIEW support is in the niScopeCal.llb file, and all calibration functions appear in the
NI-SCOPE Calibration palette. For LabWindows™/CVI™ users, the NI -SCOPE function panel
niScopeCal.fp provides access to the available functions.
For the locations of files you may need to calibrate your device, refer to the NI High-Speed
Digitizers Help, which is available on the NI-SCOPE DVD and from ni.com/manuals.
Documentation Requirements
For information about NI-SCOPE and the NI 5122/5124/5142, you can consult the following
documents:
•NI High-Speed Digitizers Getting Started Guide—provides instructions for installing and
configuring the digitizer.
•NI High-Speed Digitizers Help—includes detailed information about the digitizer and
NI-SCOPE VIs and functions.
•NI PXI/PXIe/PCI-5122 Specifications, NI PXI/PCI-5142 Specifications, or
NI PXI/PCI-5124 Specifications—includes detailed information about the digitizer and
provides the published specification values. Refer to the most recent specifications
documents online at ni.com/manuals.
• NI-SCOPE programming references—includes information about creating applications
using LabVIEW, C/C++, or CVI. These references are located within the NI High-Speed
Digitizers Help.
These documents are installed with NI-SCOPE. You also can find the latest versions of the
documentation at ni.com/manuals.
Password
The default calibration password is NI.
Table 1. Required Software for NI 5122/5124/5142 Calibration
Device NI-SCOPE Version
NI PXI-5122 2.5 or later
NI PCI-5122 2.6 or later
NI PXIe-5122 3.3.1 or later
NI PXI/PCI-5124 2.7 or later
NI PXI/PCI-5142 3.0 or later

NI 5122/5124/5142 Calibration Procedure |© National Instruments |3
Calibration Interval
National Instruments recommends a minimum calibration interval of two years for the
NI 5122/5124/5142. You should adjust the recommended calibration interval based on the
measurement accuracy demands of your application.
Test Equipment
National Instruments recommends that you use the equipment in Table 2 for calibrating the
NI 5122/5124/5142.
Note The delay times indicated in this procedure apply specifically to the Fluke
9500B calibrator. If you use a different calibrator, you may need to adjust these delay
times.
Test Conditions
Follow these guidelines to optimize the equipment and the environment during calibration:
• Always connect the calibrator test head directly to the input BNC of the digitizer, or use a
short 50 ΩBNC coaxial cable if necessary. Long cables and wires act as antennae, picking
up extra noise that can affect measurements.
• Verify that all connections to the device, including front panel connections, are secure.
• Maintain an ambient temperature of 23 ±5 °C. The device temperature will be greater than
the ambient temperature.
• Keep relative humidity below 80%.
Table 2. Test Equipment
Equipment
Recommended
Model
Parameter
Measured Requirements
Signal generator Fluke 9500B
oscilloscope
calibrator
OR
Wavetek 9500 with
high-stability
reference option
Fluke 9510 test
head
DC Accuracy DC ±(0.025% + 25 μV)
into 1 MΩor 50 Ω
Bandwidth, trigger
sensitivity
±2% output amplitude
flatness for leveled sine
wave up to 150 MHz
relative to 50 kHz into
1MΩor 50 Ω
Timing Accuracy ±2 ppm frequency
accuracy
BNC cable — — 50 Ω

4|ni.com |NI 5122/5124/5142 Calibration Procedure
• Allow a warm-up time of at least 15 minutes to ensure that the measurement circuitry is at
a stable operating temperature. Unless manually disabled, the NI-SCOPE driver
automatically loads with the operating system and enables the device. This warm-up time
ensures the digitizer is at a stable operating temperature.
• Ensure that the PXI/PXIe chassis fan speed is set to HIGH, that the fan filters are clean, and
that the empty slots contain filler panels. For more information, refer to the Maintain
Forced-Air Cooling Note to Users document available at ni.com/manuals.
• Plug the chassis/PC and the calibrator into the same power strip to avoid ground loops.
Calibration Procedures
The calibration process includes the following steps:
1. Initial Setup—Install the device and configure it in Measurement & Automation Explorer
(MAX).
2. Self-Calibration—Adjust the self-calibration constants of the device.
3. Verification—Verify the existing operation of the device. This step confirms whether the
device is operating within the published specifications prior to adjustment.
4. Adjustment—Perform an external adjustment of the device that adjusts the calibration
constants of the device. The adjustment procedure automatically stores the calibration date
on the EEPROM to allow traceability.
5. Reverification—Repeat the Verification procedure to ensure that the device is operating
within the published specifications after adjustment.
These procedures are described in more detail in the following sections.
Initial Setup
Refer to the NI High-Speed Digitizers Getting Started Guide for information about how to install
the software and hardware and how to configure the device in MAX.
Self-Calibration
The NI 5122/5124/5142 includes precise internal circuits and references used during
self-calibration to adjust for any errors caused by short-term fluctuations in the environment.
Note Allow a 15-minute warm-up period before you begin self-calibration.
Self-calibration can be initiated from MAX, NI-SCOPE Soft Front Panel (SFP), and NI-SCOPE.
MAX
To initiate self-calibration from MAX, complete the following steps:
1. Disconnect or disable any AC inputs to the digitizer.
2. Launch MAX.
3. Select My System»Devices and Interfaces.

NI 5122/5124/5142 Calibration Procedure |© National Instruments |5
4. Select the device that you want to calibrate.
5. Initiate self-calibration in one of the following ways:
•ClickSelf-Calibrate in the upper right corner of the window.
• Right-click the device name under Devices and Interfaces and select Self-Calibrate
from the drop-down menu.
NI-SCOPE Soft Front Panel
To initiate self-calibration from the SCOPE SFP, complete the following steps:
1. Disconnect or disable any AC inputs to the digitizer.
2. Launch the NI-SCOPE SFP.
3. Select the device you want to calibrate using the Device Configuration dialog box by
selecting Edit»Device Configuration.
4. Launch the Calibration dialog box by selecting Utility»Self Calibration.
5. Click OK to begin self-calibration.
NI-SCOPE
To self-calibrate the digitizer programmatically using NI-SCOPE, complete the following steps:
1. Disconnect or disable all AC inputs to the digitizer.
2. Open a session and obtain a session handle using the niScope Initialize VI.
3. Self-calibrate the digitizer using niScope Cal Self Calibrate VI.
4. End the session using the niScope Close VI.
Verification
Note After the 15-minute warm-up time, always self-calibrate the digitizer before
beginning a verification procedure.
This section describes the program you must write to verify either the calibration test limits or
the published specifications for the digitizer. Refer to Appendix A: Calibration Options to
determine which limits to use in these procedures.
Note If any of these tests fail immediately after you perform an external
adjustment, make sure that you have met the requirements listed in the Test
Equipment and Test Conditions sections before you return the digitizer to National
Instruments for repair.

6|ni.com |NI 5122/5124/5142 Calibration Procedure
Vertical Offset and Vertical Gain Accuracy
Table 3 contains the input parameters for verifying both vertical offset accuracy and vertical
gain accuracy of the digitizer.
To verify vertical offset accuracy, complete the procedures described in the Vertical Offset
Accuracy section for each of the 39 iterations in Table 3 for channel 0, then repeat the procedures
for channel 1. The Calibration Test Limits and Published Specifications for vertical offset
accuracy are shown in Table 4 (NI 5122), Table 5 (NI 5124), and Table 6 (NI 5142).
To verify vertical gain accuracy, complete the procedures described in the Vertical Gain
Accuracy section for each of the 39 iterations in Table 3 for channel 0, then repeat the procedures
for channel 1. The Calibration Test Limits and Published Specifications for vertical gain
accuracy are shown in Table 7 (NI 5122/5142) and Table 8 (NI 5124).
Table 3. NI 5122/5124/5142 Input Parameters for Vertical Offset Accuracy
and Vertical Gain Accuracy Verification
Iteration
Input
Impedance
Max Input Frequency (Hz)
RangeNI 5122/5142 NI 5124
1 50 Ω100,000,000 150,000,000 0.2
2 50 Ω100,000,000 150,000,000 0.4
3 50 Ω100,000,000 150,000,000 1
4 50 Ω100,000,000 150,000,000 2
5 50 Ω100,000,000 150,000,000 4
6 50 Ω100,000,000 150,000,000 10
7 50 Ω35,000,000 60,000,000 0.2
8 50 Ω35,000,000 60,000,000 0.4
9 50 Ω35,000,000 60,000,000 1
10 50 Ω35,000,000 60,000,000 2
11 50 Ω35,000,000 60,000,000 4
12 50 Ω35,000,000 60,000,000 10
13 50 Ω20,000,000 20,000,000 0.2
14 50 Ω20,000,000 20,000,000 0.4
15 50 Ω20,000,000 20,000,000 1
16 50 Ω20,000,000 20,000,000 2
17 50 Ω20,000,000 20,000,000 4

NI 5122/5124/5142 Calibration Procedure |© National Instruments |7
18 50 Ω20,000,000 20,000,000 10
19 1MΩ100,000,000 150,000,000 0.2
20 1MΩ100,000,000 150,000,000 0.4
21 1MΩ100,000,000 150,000,000 1
22 1MΩ100,000,000 150,000,000 2
23 1MΩ100,000,000 150,000,000 4
24 1MΩ100,000,000 150,000,000 10
25 1MΩ100,000,000 150,000,000 20
26 1MΩ35,000,000 60,000,000 0.2
27 1MΩ35,000,000 60,000,000 0.4
28 1MΩ35,000,000 60,000,000 1
29 1MΩ35,000,000 60,000,000 2
30 1MΩ35,000,000 60,000,000 4
31 1MΩ35,000,000 60,000,000 10
32 1MΩ35,000,000 60,000,000 20
33 1MΩ20,000,000 20,000,000 0.2
34 1MΩ20,000,000 20,000,000 0.4
35 1MΩ20,000,000 20,000,000 1
36 1MΩ20,000,000 20,000,000 2
37 1MΩ20,000,000 20,000,000 4
38 1MΩ20,000,000 20,000,000 10
39 1MΩ20,000,000 20,000,000 20
Table 3. NI 5122/5124/5142 Input Parameters for Vertical Offset Accuracy
and Vertical Gain Accuracy Verification (Continued)
Iteration
Input
Impedance
Max Input Frequency (Hz)
RangeNI 5122/5142 NI 5124

8|ni.com |NI 5122/5124/5142 Calibration Procedure
Vertical Offset Accuracy
Complete the following steps to verify vertical offset accuracy of the NI 5122/5124/5142. You
must verify both channels with each iteration in Table 3.
1. Open a session and obtain a session handle using the niScope Initialize VI.
Note Throughout the procedure, refer to the C/C++ function call parameters for the
LabVIEW input values.
2. Configure the input impedance and the maximum input frequency using the
niScope Configure Chan Characteristics VI.
3. Configure the common vertical properties using the niScope Configure Vertical VI.
LabVIEW VI C/C++ Function Call
Call niScope_init with the
following parameters:
resourceName: The device name
assigned by MAX
idQuery: VI_FALSE
resetDevice: VI_TRUE
LabVIEW VI C/C++ Function Call
Call
niScope_ConfigureChan
Characteristics with the
following parameters:
vi: The instrument handle from
niScope_init
channelList: "0"
inputImpedance: The Input
Impedance value in Table 3 for
the current iteration
maxInputFrequency: The
Maximum Input Frequency
value in Table 3 for the current
iteration

NI 5122/5124/5142 Calibration Procedure |© National Instruments |9
4. Configure the horizontal properties using the niScope Configure Horizontal Timing VI.
5. Commit all the parameter settings to hardware using the niScope Commit VI.
LabVIEW VI C/C++ Function Call
Call
niScope_ConfigureVerti
cal with the following
parameters:
coupling: NISCOPE_VAL_DC
probeAttenuation: 1.0
vi: The instrument handle from
niScope_init
channelList: "0"
range: The Range value in
Table 3 for the current iteration
offset: 0.0
enabled:
NISCOPE_VAL_TRUE
LabVIEW VI C/C++ Function Call
Call niScope_Configure
HorizontalTiming with the
following parameters:
enforceRealtime:
NISCOPE_VAL_TRUE
numRecords: 1
vi: The instrument handle from
niScope_init
minSampleRate: 10,000,000
refPosition: 50.0
minNumPts: 100,000
LabVIEW VI C/C++ Function Call
Call niScope_Commit with the
following parameter:
vi: The instrument handle from
niScope_init

10 |ni.com |NI 5122/5124/5142 Calibration Procedure
6. Short-circuit the channel 0 input of the digitizer by connecting the calibrator test head
directly to the digitizer and grounding the output of the calibrator.
7. Wait 500 ms for the calibrator to ground its output.
8. Initiate a waveform acquisition using the niScope Initiate Acquisition VI.
9. Fetch a waveform from the digitizer and perform a voltage average measurement using the
niScope Fetch Measurement (poly) VI. Select the Measurement Scalar DBL instance of
the VI.
Compare the resulting average voltage to the value listed in the Calibration Test Limits
column or the Published Specifications column in Table 4 (NI 5122), Table 5 (NI 5124), or
Table 6 (NI 5142) that corresponds to the vertical range used.
Note The inputImpedance and maxInputFrequency do not affect the test limit
value.
If the result is within the selected test limit, the device has passed this portion of the
verification.
10. Repeat steps 2 through 9 for each iteration in Table 3.
11. Move the calibrator test head to the digitizer input channel 1 and repeat steps 2 through 10
for every configuration in Table 3, changing the value of the channelList parameter from
"0" to "1".
LabVIEW VI C/C++ Function Call
Call niScope_Initiate
Acquisition with the
following parameter:
vi: The instrument handle from
niScope_init
LabVIEW VI C/C++ Function Call
Call niScope_Fetch
Measurement with the
following parameters:
timeout: 1.0
vi: The instrument handle from
niScope_init
channelList: "0"
scalarMeasFunction:
NISCOPE_VAL_VOLTAGE_
AVERAGE