National Instruments NI PXI-5404 Manual

CALIBRATION PROCEDURE
NI PXI-5404
This document contains step-by-step instructions for writing a calibration procedure for the
NI PXI-5404 100 MHz Frequency Source.
Contents
Calibration Overview ............................................................................................................... 2
What Is External Calibration? .......................................................................................... 2
Why Should You Calibrate?............................................................................................. 2
How Often Should You Calibrate?................................................................................... 2
Equipment and Other Test Requirements................................................................................. 2
Test Equipment................................................................................................................. 2
Test Conditions.................................................................................................................4
Documentation.................................................................................................................. 4
Software............................................................................................................................ 4
Writing Your Calibration Procedure ........................................................................ 4
Calibration Software................................................................................................. 4
Calibration Procedures in C...................................................................................... 6
Calibration Procedures in LabVIEW........................................................................ 6
Calibration Procedures in Visual Basic .................................................................... 6
Verification ............................................................................................................................... 7
Verifying Frequency Accuracy ........................................................................................ 8
Verifying SINE Out Amplitude Accuracy ....................................................................... 9
Verifying SINE Out Amplitude Passband Flatness.......................................................... 10
Verifying CLOCK Out Duty Cycle Accuracy ................................................................. 13
External Adjustment ................................................................................................................. 14
Overview of Calibration Constants .................................................................................. 14
VCXO DAC ............................................................................................................. 14
GAIN DAC............................................................................................................... 15
SYNC DAC .............................................................................................................. 15
Setting Up and Configuring the NI 5404.......................................................................... 15
Adjusting the NI 5404 ...................................................................................................... 16
Adjusting the VCXO DAC for Frequency Accuracy ............................................... 17
Adjusting the SINE Out Amplitude.......................................................................... 20
Adjusting the CLOCK Out Duty Cycle.................................................................... 25
Closing the Calibration Session........................................................................................ 28
Calibration Function Reference................................................................................................ 28
Where to Go for Support .......................................................................................................... 48

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Calibration Overview
This section describes external calibration and explains why and how often you should calibrate
your modules.
What Is External Calibration?
External calibration is a set of operations that compares the signals generated by a module or a
system to external standards. The result of an external calibration can be used to determine the
output error and can be used to correct the errors in the adjustment process.
The calibration process consists of verification, adjustment, and reverification. During
verification, you compare the measured performance to an external standard of known
measurement uncertainty to confirm that the performance of the module is better than the
published specifications. During adjustment, you correct the generation error of the module by
adjusting the calibration constants and storing the new calibration constants in the onboard
EEPROM. The host computer reads the calibration constants and the software uses them to
compensate for errors and to present a calibrated output to the user. Reverification means
repeating verification after the adjustment process.
Why Should You Calibrate?
The accuracy of electronic components drifts with time and temperature, which can affect
generation accuracy. Calibration restores the NI 5404 to its specified accuracy and ensures that
it still meets National Instruments standards.
How Often Should You Calibrate?
NI recommends performing a complete calibration at least once every year. You can shorten this
interval based on the demands of your application.
Equipment and Other Test Requirements
This section describes the test equipment, test conditions, documentation, and software required
for calibration.
Test Equipment
External calibration requires different equipment for each applicable specification. Refer to
Table 1 for a list of equipment.

NI PXI-5404 Calibration Procedure |© National Instruments |3
Table 1. Equipment Required for Calibrating NI 5404 Modules
Instrument
Applicable
Specification
Minimum
Specifications
Recommended
Instrument(s)
Digital multimeter
(DMM)
SINE out amplitude
accuracy
AC amplitude accuracy
better than ±0.1% at
50 kHz at 4 Vpk-pk
NI PXI-4070
Agilent (HP) 34401A
Keithley 2000
Male banana to female
BNC adapter
— —
Male BNC to female
SMB cable
50 Ω—
Spectrum analyzer/
Frequency Counter
Frequency accuracy Bandwidth >150 MHz
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
FSU26
Male SMA to female
SMB cable
— —
Oscilloscope CLOCK out duty
cycle accuracy
Bandwidth ≥500 MHz
Timebase Accuracy:
≤200 ppm
Tektronix TDS3054
Male BNC to female
SMB cable
— —
Power meter and thermal
power sensor
SINE out amplitude
passband flatness
±0.12 dB accuracy for
flatness measurements
from 9 kHz to 105 MHz
Rohde & Schwarz
NRVS meter
Rohde & Schwarz
NRV-Z51 or
Rohde & Schwarz
NRV-Z53 sensor
Rohde & Schwarz
NRP-Z91
Female N-Type to
female SMB cable
50 Ω—

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Test Conditions
Follow these guidelines to optimize the connections and the environment during calibration:
• Keep connections to the NI 5404 module short.
• Keep relative humidity below 80%.
• Maintain a temperature between 18 and 28 °C.
Documentation
For information on installing NI 5404 modules, you may find the following documents helpful:
•NI Signal Generators Getting Started Guide
•NI Signal Generators Help
•NI PXI-5404 Specifications
The NI Signal Generators Help includes detailed information on the NI-FGEN instrument driver
functions. You can access this help file by selecting Start»Programs»National Instruments»
NI-FGEN»NI Signal Generators Help. The NI Signal Generators Getting Started Guide
provides instructions for installing and configuring NI signal generators.
For the latest versions of NI manuals, refer to ni.com/manuals.
Software
This section describes the software you need to calibrate the NI 5404.
Writing Your Calibration Procedure
The calibration process is described in the External Adjustment section, including step-by-step
instructions on calling the appropriate calibration functions.
Many of the calibration functions use constants defined in the niArbCal.h file. To use these
constants, you must include niArbCal.h in your code. Refer to Table 2 for file locations.
Calibration Software
Note Only the Traditional NI-DAQ drivers support PXI-5404 calibration. The
required functions of Traditional NI-DAQ are supported only by 32-bit versions of
Windows XP (recommmended) and earlier operating systems.
The calibration procedure requires the latest version of NI-FGEN on the computer system that
is controlling the NI 5404. NI-FGEN configures and controls NI 5404 modules. NI-FGEN ships
with the NI 5404. You can also download NI-FGEN from ni.com/updates. NI-FGEN
supports programming of all NI signal generators using a number of languages, including
LabVIEW, LabWindows™/CVI™, Microsoft Visual C++, and Microsoft Visual Basic. When
you install NI-FGEN, you only need to install support for the programming language that you
intend to use.

NI PXI-5404 Calibration Procedure |© National Instruments |5
Although NI-FGEN includes calibration support, the calibration application programming
interface (API) is separate from NI-FGEN. During verification and adjustment, you use
two APIs: the NI-FGEN API and the NI HSSources API. The NI-FGEN API controls the
module both during normal operation and during the verification procedure. The NI HSSources
API controls the module during the adjustment procedure.
NI-FGEN automatically installs the files listed in Table 2.
Table 2. Calibration File Locations
File Name and Location Description
<system directory>\niArbCal.dll The NI HSSources calibration
toolkit library. This toolkit provides
the functionality for calibrating
your module.
VXIpnp\WinNT(Win95)\lib\msc\
niArbCal.lib
VXIpnp\WinNT(Win95)\lib\bc\
niArbCal.lib
A .lib file that allows you
to create applications that call
functions in the niArbCal.dll:
• If you build an application using
Microsoft Visual C/C++, link to
msc\niArbCal.lib.
• If you build an application using
Borland C/C++, link to
bc\niArbCal.lib.
• If you build an application using
LabWindows/CVI, link to the
library appropriate to your
current compatibility mode
(msc for Microsoft Visual C/
C++, bc for Borland)
VXIpnp\WinNT(Win95)\include\
niArbCal.h
A header file for the accessible
functions in the niArbCal.dll.
You must include this file in any
C code that you write to call these
functions.
VXIpnp\WinNT(Win95)\nifgen\
Examples\Calibration\
ExternalCalibrationExample5404.c
Example written in C that illustrates
a calibration procedure using the
functions in the niArbCal.dll.

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Calibration Procedures in C
To write calibration procedures in C, you must include the niArbCal.h file in the code that
calls the calibration functions, and you must link the niArbCal.lib file into the build of your
executable.
Calibration Procedures in LabVIEW
To write calibration procedures in LabVIEW, you must use the VIs included in the
niHSSources_Cal.llb. This library contains a VI for each function exported by the
niArbCal.dll, as well as other useful functions. After installation, all of these VIs appear
within the Legacy Calibration palette under Functions»Measurement I/O»NI-FGEN»
Calibration»Legacy Device Calibration»Calibrating the 5404. The NI HSSources
Calibration palette also contains example VIs that illustrate how to use the calibration functions.
Calibration Procedures in Visual Basic
To write calibration procedures in Visual Basic, complete the following steps:
1. Configure the project to reference the niArbCal.dll by selecting Project»References
from the menu bar.
2. Click Browse and navigate to your system directory.
3. Find and select niArbCal.dll.
4. Click Open.
5. Click OK.
VXIpnp\WinNT(Win95)\nifgen\Examples\
Calibration\VisualBasic\
SimpleCalibrationExample.vbp
VXIpnp\WinNT(Win95)\nifgen\Examples\
Calibration\VisualBasic\
SimpleCalibrationExample.vbw
VXIpnp\WinNT(Win95)\nifgen\Examples\
Calibration\VisualBasic\
SimpleCalibrationExample.frm
Example written in Visual Basic
that illustrates using the functions
in the niArbCal.dll.
LabVIEW 6 (6.1)\instr.lib\
niHSSources\niHSSources_Calibration\
niHSSources_Cal.llb
This LabVIEW LLB contains VIs
that correspond to the functions in
the niArbCal.dll.
LabVIEW 6 (6.1)\instr.lib\
niHSSources\niHSSources_Calibration\
niHSSources_Cal_5404_External_Calibra
tion_Example.llb
This LabVIEW LLB contains VIs
that demonstrate an external
adjustment procedure using the
VIs in niHSSources_Cal.llb.
Table 2. Calibration File Locations (Continued)
File Name and Location Description

NI PXI-5404 Calibration Procedure |© National Instruments |7
You can then use the niArbCal functions in your code and look up the functions, parameters,
and constants in the Object Browser.
Verification
This section provides step-by-step instructions for verifying the NI 5404 specifications.
Verification determines whether the module is performing within its specifications prior to
adjustment. Verification and adjustment together comprise a complete calibration. To verify that
the NI 5404 still meets its specifications, you must use NI-FGEN to control the NI 5404 module.
The following steps describe the code you use to generate the appropriate signals, as well as the
NI-FGEN function calls you make to verify specifications. The code varies depending on which
API you use: LabVIEW, LabWindows/CVI, or Visual Basic. The examples shown in this
section use LabWindows/CVI code, but LabVIEW has a corresponding VI for each function.
You can verify the following specifications for NI 5404 modules:
• SINE out amplitude accuracy
• Frequency accuracy
• CLOCK out duty cycle accuracy
• SINE out amplitude passband flatness
Refer to Table 1 for information concerning which instrument to use for each characteristic.
The verification procedure for each of these specifications includes setting up, programming,
and cleaning up.

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Figure 1 shows the NI 5404 connectors.
Figure 1. NI 5404 I/O Connectors
Verifying Frequency Accuracy
Use the spectrum analyzer specified in Table 1 to measure the frequency accuracy of the
NI 5404 module. Connect the SINE out of the NI 5404 to the input of the spectrum analyzer
using an SMB to SMA cable.
Generate a 10 MHz frequency using the NI 5404 module by completing the following steps:
1. Call niFgen_init() to initialize the module you are testing and to create an I/O session.
Set the following parameters:
•vi—The output that is passed in by reference to the verification functions as
sessionHandle
•resourceName—"DAQ::#", where #is the device number
•ID Query—True
•Reset Device—True
SINE
REF
OUT
REF
IN
PFI 0
CH 0
CLOCK
ACCESS ACTIVE
NI PXI-5404
100 MHz Freq Source

NI PXI-5404 Calibration Procedure |© National Instruments |9
2. Call niFgen_ConfigureStandardWaveform() to select the channel to output a
waveform. Set the following parameters:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
•Channel_Name—"0"
•Amplitude—2
•Frequency—10000000
•Start phase—0
•DC offset—0
•Waveform—NIFGEN_VAL_WFM_SINE
3. Call niFgen_InitiateGeneration() to initiate signal generation. This function
causes the NI 5404 to leave its configuration state and enter its signal generation state. Set
the following parameter:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
4. Measure the frequency of the SINE output using a spectrum analyzer specified in Table 1.
To determine if the measured frequency is within the specification of the NI 5404, you must
determine the measurement error of the instrument that you used to measure the frequency
and account for this error when comparing the measured frequency to the frequency
accuracy listed in the Specifications for the NI PXI-5404.
5. Call niFgen_close() to close the module I/O session, destroy the instrument driver
session and all of its properties, and release any memory resources the driver uses. Set the
following parameter:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
You have completed verifying the module oscillator frequency accuracy of the NI 5404.
Verifying SINE Out Amplitude Accuracy
Use a DMM specified in Table 1 to measure the SINE out amplitude accuracy of the NI 5404.
Connect the SINE out of the NI 5404 to the input of the DMM using the male banana to female
BNC adapter and the BNC to SMB cable.
Note A 50 Ωterminator is not used for this measurement.
Generate a 4 Vpk-pk (into high impedance) 50 kHz sine wave as follows:
1. Call niFgen_init() to initialize the module you are testing and to create an I/O session.
Set the following parameters:
•vi—The output that is passed in by reference to the verification functions as
sessionHandle
•resourceName—"DAQ::#", where #is the device number

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•ID Query—True
•Reset Device—True
2. Call niFgen_ConfigureStandardWaveform() to select the channel to output a
waveform. Set the following parameters:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
•Channel_Name—"0"
•Amplitude—2
•Frequency—50000
•Start phase—0
•DC offset—0
•Waveform—NIFGEN_VAL_WFM_SINE
3. Call niFgen_InitiateGeneration() to initiate signal generation. This function
causes the NI 5404 to leave its configuration state and enter its signal generation state. Set
the following parameter:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
4. Measure the rms voltage of the SINE output using a DMM specified in Table 1. To
determine if the measured voltage is within the amplitude accuracy specification of the
NI 5404, you must determine the measurement error of the DMM that you used to measure
the rms voltage and account for this error when comparing the measured voltage to the
amplitude accuracy listed in the Specifications for the NI PXI-5404.
Note A 4 Vpk-pk sine wave has an rms amplitude of 1.41421 Vrms.
5. Call niFgen_close() to close the module I/O session, destroy the instrument driver
session and all of its properties, and release any memory resources the driver uses. Set the
following parameter:
•vi—The output value sessionHandle you obtained from the niFgen_init
function
You have completed verifying the SINE out amplitude accuracy of the NI 5404.
Verifying SINE Out Amplitude Passband Flatness
The following procedure measures SINE out amplitude over several frequencies to verify that
the SINE out amplitude passband flatness meets NI 5404 specifications.
Complete the following steps to verify SINE out amplitude passband flatness:
1. Call niFgen_init() to initialize the module you are testing and to create the I/O session.
Set the following parameters:
•vi—The output that is passed in by reference to the verification functions as
sessionHandle
•resourceName—"DAQ::#", where #is the device number