NI PXI-5422 Manual

PXI-5422

CALIBRATION PROCEDURE
NI PXI-5422
This document contains instructions for calibrating the NI PXI-5422 arbitrary waveform
generator. This calibration procedure is intended for metrology labs. It describes specific
programming steps for writing an external calibration procedure for the NI PXI-5422.
Refer to ni.com/calibration for additional information about calibration solutions from
National Instruments.
Contents
Software Requirements............................................................................................................. 1
Documentation Requirements .................................................................................................. 2
Password................................................................................................................................... 3
Calibration Interval................................................................................................................... 3
Self-Calibration Procedures...................................................................................................... 3
MAX................................................................................................................................. 4
FGEN Soft Front Panel..................................................................................................... 4
NI-FGEN .......................................................................................................................... 4
External Calibration Options ....................................................................................................5
Complete Calibration........................................................................................................ 6
Optional Calibration ......................................................................................................... 6
External Calibration Requirements .......................................................................................... 8
Test Equipment................................................................................................................. 8
Test Conditions.................................................................................................................9
External Calibration Procedures............................................................................................... 9
Writing Your Calibration Procedure ................................................................................ 9
Calibration Procedures in LabVIEW........................................................................ 9
Calibration Procedures in LabWindows/CVI........................................................... 9
Calibration Procedures in C...................................................................................... 10
Verifying NI PXI-5422 Specifications ............................................................................. 10
Verifying the Oscillator Frequency Accuracy.......................................................... 11
Verifying the DC Gain and Offset Accuracy ........................................................... 14
Verifying the AC Voltage Amplitude Absolute Accuracy....................................... 27
Verifying Frequency Response (Flatness)................................................................ 30
Adjusting the NI PXI-5422............................................................................................... 37
Initializing the External Calibration Session ............................................................ 39
Adjusting the Analog Output.................................................................................... 39
Adjusting the Oscillator Frequency.......................................................................... 52
Adjusting the Calibration ADC ................................................................................ 55
Closing the External Adjustment Session ................................................................ 59

2|ni.com |NI PXI-5422 Calibration Procedure
Calibration Utilities................................................................................................................... 60
MAX .................................................................................................................................60
FGEN SFP ........................................................................................................................60
NI-FGEN .......................................................................................................................... 60
Where to Go for Support ..........................................................................................................61
Software Requirements
Calibrating the NI PXI-5422 requires installing NI-FGEN version 2.2 or later on the calibration
system. You can download NI-FGEN from the National Instruments website at ni.com/
updates. NI-FGEN supports programming the Self-Calibration Procedures and the External
Calibration Procedures in the LabVIEW, LabWindows™/CVI™, and C application
development environments (ADEs). When you install NI-FGEN, you need to install support
only for the ADE that you intend to use.
LabVIEW support is in the niFgen.llb file, and all calibration VIs appear in the NI-FGEN
Calibration palette. For LabWindows/CVI users, the NI-FGEN function panel (niFgen.fp)
provides access to the available functions.
For the locations of files you may need to calibrate your device, refer to the NI-FGEN Readme,
which is available on the NI-FGEN DVD.
Calibration functions are C function calls or LabVIEW VIs in NI-FGEN. In this document, the
C function call is shown first, followed by the corresponding LabVIEW VI or NI-FGEN
LabVIEW property node, in parentheses. The C function calls are valid for any compiler capable
of calling a 32-bit DLL. Many of the functions use constants defined in the niFgen.h file.
To use these constants in C, you must include niFgen.h in your code when you write the
calibration procedure. Refer to Table 1 for file locations.
Table 1. Calibration File Locations
File Name and Location Description
IVI\Bin\niFgen_32.dll The NI-FGEN library, which provides the
functionality for calibrating the
NI PXI-5422.
IVI\Lib\msc\niFgen.lib Allows you to create applications that call
functions in the niFgen_32.dll:
• For Microsoft Visual C/C++, link to
msc\niFgen.lib.
• For LabWindows/CVI, link to the
library appropriate to your current
compatibility mode (msc for
Microsoft Visual C/C++).

NI PXI-5422 Calibration Procedure |© National Instruments |3
The calibration process is described in the Self-Calibration Procedures and the External
Calibration Procedures sections, including step-by-step instructions on calling the appropriate
calibration functions.
Documentation Requirements
Consult the following documents for information about the NI PXI-5422, NI-FGEN, and your
application software. All documents are available on ni.com, and the Help files install with the
software.
IVI\Include\niFgen.h A header file for the accessible functions
in the niFgen_32.dll. You must
include this file in any C code that you
write to call these functions.
<LabVIEW>\instr.lib\niFgen\
niFgen.llb (LabVIEW)
Contains VIs that correspond to the
functions in the niFgen_32.dll.
IVI\Drivers\niFgen\niFgen.fp(CVI) Contains the function panels for the
function in the niFgen32.dll.
NI Signal Generators Getting Started Guide
Contains: NI-FGEN installation, hardware installation, and hardware programming
NI PXI-5422 Specifications
Contains: NI PXI-5422 specifications and calibration interval
NI-FGEN Readme
Contains: Operating system and application software support in NI-FGEN
NI Signal Generators Help
Contains: Detailed information about NI PXI-5422
Table 1. Calibration File Locations (Continued)
File Name and Location Description

4|ni.com |NI PXI-5422 Calibration Procedure
Password
The default calibration password is NI.
Calibration Interval
National Instruments recommends a calibration interval of two years for the NI PXI-5422. You
should adjust the recommended calibration interval based on the measurement accuracy
demands of your application. Refer to the External Calibration Options section for more
information.
Self-Calibration Procedures
The NI PXI-5422 can perform self-calibration, which adjusts the gain and offset of the main and
direct analog paths. Self-calibration exclusively uses an onboard A/D converter (ADC) to
measure the output voltage. You can implement self-calibration on the NI PXI-5422 by
following procedures similar to the Verifying the DC Gain and Offset Accuracy and the
Adjusting the Analog Output procedures described in this document. However, output
impedance, oscillator frequency, and the calibration ADC are not adjusted during
self-calibration.
Caution Although you can use self-calibration repeatedly, self-calibrating the
NI PXI-5422 more than a few times a day may cause excessive wear on the relays
over time.
You can initiate self-calibration interactively from Measurement & Automation Explorer
(MAX) or from the FGEN Soft Front Panel (SFP). Alternately, you can initiate self-calibration
programmatically using NI-FGEN.
LabVIEW Help
Contains: LabVIEW programming concepts and reference information about
NI-FGEN VIs and functions
NI-FGEN C Reference Help
Contains: Reference information for NI-FGEN C functions and NI-FGEN
C properties

NI PXI-5422 Calibration Procedure |© National Instruments |5
MAX
To initiate self-calibration from MAX, complete the following steps:
1. Launch MAX.
2. Select My System»Devices and Interfaces»PXI System.
3. Select the device that you want to calibrate.
4. Initiate self-calibration in one of the following ways:
•ClickSelf-Calibrate in the upper right corner.
• Right-click the device name and select Self-Calibrate from the drop-down menu.
FGEN Soft Front Panel
To initiate self-calibration from the FGEN SFP, complete the following steps:
1. Select the device that you want to calibrate using the Device Configuration dialog box
(Edit»Device Configuration).
2. Open the Calibration dialog box (Utility»Calibration).
3. Click Perform self-calibration.
NI-FGEN
To self-calibrate the NI PXI-5422 programmatically using NI-FGEN, complete the following
steps:
1. Call niFgen_init (niFgen Initialize VI) to open an NI-FGEN session using the following
parameters:
•resourceName: The name of the device that you want to calibrate. You can find this
name under Devices and Interfaces in MAX.
•IDQuery: VI_TRUE
•resetDevice: VI_TRUE
•vi: A pointer to a ViSession. The variable passed by reference through this parameter
receives the value that identifies the session created by this function. This value acts as the
session handle and is passed as the first parameter to all subsequent NI-FGEN functions.
2. Call niFgen_SelfCal (niFgen Self Cal VI) using the following parameter:
•vi: The session handle returned from niFgen_init
3. Call niFgen_close (niFgen Close VI) to close the NI-FGEN session using the following
parameter:
•vi: The session handle returned from niFgen_init

6|ni.com |NI PXI-5422 Calibration Procedure
External Calibration Options
External calibration involves both verification and adjustment. Verification is the process of
testing the device to ensure that the output accuracy is within certain specifications. You can use
verification to ensure that the adjustment process was successful or to determine if the
adjustment process needs to be performed.
Adjustment is the process of measuring and compensating for device performance to improve
the output accuracy. Performing an adjustment updates the calibration date, resetting the
calibration interval. The device is guaranteed to meet or exceed its published specifications for
the duration of the calibration interval.
This document provides two sets of test limits for most verification stages, the calibration test
limits and the published specifications. The calibration test limits are more restrictive than the
published specifications. If all the output errors determined during verification fall within the
calibration test limits, the device is guaranteed to meet or exceed its published specifications for
a full calibration interval (two years). For this reason, you must verify against the calibration test
limits when performing verification after adjustment.
If all the output errors determined during verification fall within the published specifications, but
not within the calibration test limits, the device meets its published specifications. However, the
device may not remain within these specifications for another two years. The device will meet
published specifications for the rest of the current calibration interval.
In this case, you can perform an adjustment if you want to improve the output accuracy or reset
the calibration interval. If some output errors determined during verification do not fall within
the published specifications, you must perform an adjustment to restore the device operation to
its published specifications.
The Complete Calibration section describes the recommended calibration procedure. The
Optional Calibration section describes alternate procedures that allow you to skip adjustment if
the device already meets its calibration test limits or published specifications.

NI PXI-5422 Calibration Procedure |© National Instruments |7
Complete Calibration
Performing a complete calibration is the recommended way to guarantee that the NI PXI-5422
meets or exceeds its published specifications for a two-year calibration interval. At the end of
the complete calibration procedure, you verify that the output error falls within the calibration
test limits. Figure 1 shows the programming flow for complete calibration.
Figure 1. Complete Calibration Programming Flow
Optional Calibration
You can choose to skip the adjustment steps of the calibration procedure if the output error is
within the calibration test limits or the published specifications during the first verification. If all
the output errors determined during the first verification fall within the calibration test limits, the
device is guaranteed to meet or exceed its published specifications for a full calibration interval.
In this case, you can update the calibration date, effectively resetting the calibration interval,
without actually performing an adjustment. Refer to the Adjusting the NI PXI-5422 section for
more information.
Adjust
(Cal Datesand
Temperatures
Updated)
Verify
Document
Post-Adjustment
Results
Meets
Calibration
Te st Limits?
Review
Ver ification/
Adjustment
Procedure or
Return Device
Verify
Self-Calibrate
Calibration/
Verification
Complete
Ye sNo
Document
Pre-Adjustment
Results

8|ni.com |NI PXI-5422 Calibration Procedure
If all the output errors determined during the first verification fall within the published
specifications, but not within the calibration test limits, adjustment is also optional. However,
you cannot update the calibration date because the device may not necessarily operate within the
published specifications for an additional two years.
Note Regardless of the results of the first verification, if you choose to perform an
adjustment, you must verify that the output error falls within the calibration test limits
at the end of the calibration procedure.
Figure 2 shows the programming flow for the optional calibration.
Figure 2. Optional Calibration Programming Flow
Self-Calibrate
Verify
Document
Pre-Adjustment
Results
Meets
Calibration
Te st Limits?
Meets
Published
Specifications?
Update Calibration
Datesand
Temperatures
Without Adjusting
Results
Within
Published Specs
(Adjustment
Optional)
Adjust
Anyway?
Adjust
(Cal Datesand
Temperatures
Updated)
Verify Document
Post-Adjustment
Results
Meets
Calibration
Te st Limits?
Calibration/
Verification
Complete
Review
Verification/
Adjustment
Procedure or
Return Device
Ye sNo
Ye sNo
Ye sNo
Ye s
No

NI PXI-5422 Calibration Procedure |© National Instruments |9
External Calibration Requirements
This section describes the test equipment and test conditions required for calibration.
Test Equipment
External calibration requires different equipment for each applicable specification. Refer to
Table 2 for a list of equipment.
Table 2. Equipment Required for Calibrating the NI PXI-5422
Instrument
Applicable
Specification
Minimum
Specifications
Recommended
Instrument
Digital multimeter
(DMM)
AC accuracy,
DC gain and
offset
DCV accuracy:
≤0.05%
DC input impedance:
≥1GΩ
ACV accuracy:
≤0.16%
AC input impedance:
≥1MΩ
Bandwidth: ≥100 kHz
Resolution ≤1 µV
NI PXI-4070
Agilent HP 34401A
Keithley 2000
Banana(m)-to-BNC(f)
adapter
— —
BNC(m)-to-SMB(f)
cable
50 Ω, RG-223 —
Spectrum analyzer,
frequency meter, or
signal source analyzer
Frequency
accuracy
Ability to measure
10 MHz or greater
sine waves
Frequency accuracy
to ≤500 ppb
NI PXI-5660
Agilent HP 8560E
Agilent HP 53131A
or HP 53132A with
timebase option
001, 010, or 012
Rohde & Schwarz
(R&S) FSUP