National Instruments PXI User manual

CALIBRATION PROCEDURE
NI 5114
This document contains instructions for writing an external calibration procedure for the
NI PXI/PXIe/PCI-5114. For more information about calibration, visit ni.com/
calibration.
Contents
Software.................................................................................................................................... 2
Documentation.......................................................................................................................... 3
Password................................................................................................................................... 4
Calibration Interval................................................................................................................... 4
External Calibration.......................................................................................................... 4
Self-Calibration ................................................................................................................4
Test Equipment......................................................................................................................... 4
Calibration Procedures ............................................................................................................. 5
Initial Setup....................................................................................................................... 5
Test Conditions......................................................................................................... 5
Self-Calibration ................................................................................................................6
MAX......................................................................................................................... 6
NI-SCOPE Soft Front Panel ..................................................................................... 6
NI-SCOPE ................................................................................................................ 7
Verification ....................................................................................................................... 8
Vertical Offset and Vertical Gain Accuracy............................................................. 8
Programmable Vertical Offset Accuracy ................................................................. 18
Timing Accuracy ...................................................................................................... 24
Bandwidth and Flatness............................................................................................ 27
Trigger Sensitivity .................................................................................................... 32
Adjustment........................................................................................................................ 37
Appendix A: Calibration .......................................................................................................... 41
Complete Calibration........................................................................................................ 41
Appendix B: Calibration Utilities............................................................................................. 42
MAX................................................................................................................................. 42
NI-SCOPE ........................................................................................................................43
Where to Go for Support .......................................................................................................... 43

2|ni.com |NI 5114 Calibration Procedure
Software
To calibrate the NI 5114, install the following versions of NI-SCOPE.
You can download NI-SCOPE from the Instrument Driver Network at ni.com/idnet.
NI-SCOPE supports programming the Self-Calibration and Verification sections in a number of
programming languages. However, only LabVIEW and C are supported for the Adjustment
section.
NI-SCOPE includes all the functions and attributes necessary for calibrating the NI 5114.
LabVIEW support is installed in niScopeCal.llb, and all calibration functions appear in the
function palette. For LabWindows™/CVI™, the NI-SCOPE function panel niScopeCal.fp
provides further help on the functions available in CVI. Refer to Table 2 for installed file
locations.
Calibration functions are LabVIEW VIs or C function calls in the NI-SCOPE driver. 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 niScopeCal.h file. To use these constants in C, you must include
niScopeCal.h in your code when you write the calibration procedure.
For more information on the calibration VIs and functions, refer to the NI-SCOPE Function
Reference Help or the NI-SCOPE LabVIEW Reference Help. These references can be found in
the NI High-Speed Digitizers Help. Refer to the NI-SCOPE Readme for the installed locations
of these documents.
Table 1. Required Software for NI 5114 Calibration
Device NI-SCOPE Version
NI PXI-5114 2.9 or later
NI PCI-5114 3.1 or later
NI PXIe-5114 14.1 or later
Table 2. Calibration File Locations after Installing NI-SCOPE
File Name and Location Description
IVI\Bin\niscope_32.dll NI-SCOPE driver containing the entire NI-SCOPE
API, including calibration functions.
IVI\Lib\msc\niscope.lib NI-SCOPE library for Microsoft C containing the
entire NI-SCOPE API, including calibration
functions.
LabVIEW ( version )\examples\
instr\niScope
Directory of LabVIEW NI-SCOPE example VIs,
including self-calibration.
LabVIEW ( version )\
instr.lib\niScopeCalibrate\
niScopeCal.llb
LabVIEW VI library containing VIs for calling the
NI-SCOPE calibration API.

NI 5114 Calibration Procedure |© National Instruments |3
Documentation
Consult the following documents for information about the NI PXI/PXIe/PCI-5114, NI-SCOPE,
and your application software. All documents are available on ni.com, and the Help files install
with the software.
IVI\Drivers\niScope\
niScopeCal.fp
CVI function panel file that includes external
calibration function prototypes and help on using
NI-SCOPE in the CVI environment.
IVI\Include\niScopeCal.h Calibration header file, which you must include in
any C program accessing calibration functions.
This file automatically includes niScope.h,
which defines the rest of the NI-SCOPE interface.
IVI\Drivers\niScope\
Examples
Directory of NI-SCOPE examples for CVI, C,
Visual C++, and Visual Basic.
NI High-Speed Digitizers Getting Started Guide
Contains: NI-SCOPE installation, hardware installation, and hardware programing
NI 5114 Specifications
Contains: NI PXI/PXIe/PCI-5114 specifications and calibration interval
NI-SCOPE Readme
Contains: Operating system and application software support in NI-SCOPE
NI High-Speed Digitizers Help
Contains: Detailed information about NI PXI/PXIe/PCI-5114
NI-SCOPE LabVIEW Reference Help
Contains: LabVIEW programming concepts and reference information about NI-SCOPE VIs
and functions
NI-SCOPE Function Reference Help
Contains: Reference information for NI-SCOPE C functions and NI-SCOPE C properties
Table 2. Calibration File Locations after Installing NI-SCOPE (Continued)
File Name and Location Description

4|ni.com |NI 5114 Calibration Procedure
Password
The default calibration password is NI.
Calibration Interval
External Calibration
The measurement accuracy requirements of your application determine how often you should
externally calibrate the NI 5114. NI recommends that you perform a complete external
calibration at least once every two years. You can shorten this interval based on the accuracy
demands of your application or the requirements of your processes. Refer to Appendix A:
Calibration for more information.
Self-Calibration
Self-calibration can be performed as necessary to compensate for environmental changes.
Caution Although you can use self-calibration repeatedly, self-calibrating the
NI 5114 more than a few times a day may cause excessive wear on the relays over
time.
Test Equipment
Table 3 lists the equipment required for externally calibrating the NI 5114. If you do not have
the recommended instruments, use these specifications to select a substitute calibration standard.
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.
Table 3. Required Equipment Specifications for the NI 5114 External Calibration
Required
Equipment
Recommended
Equipment
Parameter
Measured Specification
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
1MΩ
Bandwidth,
Trigger
Sensitivity
±2% output amplitude
flatness for leveled sine wave
up to 125 MHz relative to
50 kHz into 50 Ω
Timing ±2 ppm frequency accuracy
BNC cable — — 50 Ω

NI 5114 Calibration Procedure |© National Instruments |5
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 its specified range prior to calibration.
4. Adjustment—Perform an external adjustment of the device that adjusts the calibration
constants with respect to a known voltage source. 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 its specifications after adjustment.
These steps 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.
Test Conditions
Follow these guidelines to optimize the connections and the environment during calibration:
• Always connect the calibrator test head directly to the input BNC of the device, or use a
short 50 ΩBNC coaxial cable if necessary. Long cables and wires act as antennas, picking
up extra noise that can affect measurements.
• Keep relative humidity between 10 and 90% non-condensing, or consult the device
hardware documentation for the optimum relative humidity.
• Maintain an ambient temperature of 23 ±5 °C. The device temperature will be greater than
the ambient temperature.
• Allow a warm-up time of at least 15 minutes after the NI-SCOPE driver is loaded. Unless
manually disabled, the NI-SCOPE driver automatically loads with the operating system and
enables the device. The warm-up time ensures that the measurement circuitry of the
NI 5114 is at a stable operating temperature.
• Plug the PXI/PXI Express chassis or PC and the calibrator into the same power strip to
avoid ground loops.
•(PXI/PXIe) Ensure that the PXI/PXI Express chassis fan speed is set to HIGH, the fan filters
are removed, and the empty slots contain PXI chassis slot blockers and filler panels. For
more information refer to the Maintain Forced-Air Cooling Note to Users document
available at ni.com/manuals.
• Verify that all connections to the device, including front panel connections, are secure.
• Use shielded copper wire for all cable connections to the device. Use twisted-pair wire to
eliminate noise and thermal offsets.

6|ni.com |NI 5114 Calibration Procedure
Self-Calibration
The NI 5114 includes precise internal circuits and references used during self-calibration to
adjust for time and temperature drift. The device gain, offset, flatness, and trigger timing are all
corrected in self-calibration. Measuring the accuracy of these internal calibration circuits with
another instrument during external calibration provides traceability for the verification
procedure. Absolute accuracy is ensured by compensating for any error measured in the internal
references.
Note Self-calibrate the device before you perform Verification. NI-SCOPE
includes self-calibration example programs for LabVIEW, CVI, and Microsoft
Visual C.
You can initiate self-calibration using the following methods:
•MAX
• NI-SCOPE Soft Front Panel (SFP)
• NI-SCOPE
Note The device must be installed in MAX before it can be used in another
program.
MAX
To initiate self-calibration from MAX, complete the following steps:
1. Disconnect or disable any AC inputs to the device.
2. Launch MAX.
3. Select My System»Devices and Interfaces»NI-DAQmx Devices.
4. Select the device that you want to calibrate.
5. Initiate self-calibration using one of the following methods:
•ClickSelf-Calibrate in the upper right corner of MAX.
• Right-click the name of the device in the MAX configuration tree and select
Self-Calibrate from the drop-down menu.
NI-SCOPE Soft Front Panel
To initiate self-calibration from the NI-SCOPE Soft Front Panel (SFP), complete the following
steps:
1. Disconnect or disable any AC inputs to the device.
2. Launch the NI-SCOPE SFP, which is available at Start»All Programs»National
Instruments»NI-SCOPE»NI-SCOPE Soft Front Panel.
3. Select the device you want to calibrate from the Select Device dialog box. The Select
Device dialog box automatically opens when you launch the NI-SCOPE SFP.
Note To change the device, select Edit»Change Device, and select the new device
that you want to calibrate.

NI 5114 Calibration Procedure |© National Instruments |7
4. Launch the Calibration dialog box by selecting Utility»Self Calibration.
5. Click OK to begin self-calibration.
NI-SCOPE
To self-calibrate the NI 5114 programmatically using NI-SCOPE, complete the following steps:
1. Disconnect or disable any AC inputs to the device.
2. 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.
3. Self-calibrate the device using niScope Cal Self Calibrate VI.
.
Note Because the session is a standard session rather than an external calibration
session, the new calibration constants are immediately stored in the EEPROM.
Therefore, you can include this procedure in any application that uses the device.
LabVIEW VI C/C++ Function Call
Call niScope_init with the
following parameters:
vi: The returned session handle that
you use to identify the instrument in all
subsequent NI-SCOPE driver function
calls
resourceName: The device name
assigned by MAX
idQuery: VI_FALSE
resetDevice: VI_TRUE
LabVIEW VI C/C++ Function Call
Call niScope_CalSelf
Calibrate with the
following parameters:
sessionHandle: The
instrument handle from
niScope_init
channelList: VI_NULL
option: VI_NULL

8|ni.com |NI 5114 Calibration Procedure
4. End the session using the niScope Close VI.
Verification
Note After the 15-minute warm-up time, always self-calibrate the NI 5114 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 NI 5114.
Note If any of these tests fail after you perform an external adjustment, make sure
that you have met the requirements listed in the Test Equipment and Calibration
Procedures sections before you return the device to National Instruments for repair.
Vertical Offset and Vertical Gain Accuracy
Table 4 contains the input parameters for verifying both vertical offset accuracy and vertical gain
accuracy of the NI 5114.
To verify vertical offset accuracy, complete the procedures described in the Vertical Offset
Accuracy section for each of the 20 iterations listed in Table 4 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 5.
To verify vertical gain accuracy, complete the procedures described in the Vertical Gain
Accuracy section for each of the 20 iterations listed in Table 7 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 6.
LabVIEW VI C/C++ Function Call
Call niScope_close with the
following parameter:
vi: The instrument handle from
niScope_init
Table 4. NI 5114 Input Parameters for Vertical Offset Accuracy
and Vertical Gain Accuracy Verification
Iteration Max Input Frequency (MHz) Range
1 125 0.04
2 125 0.1
3 125 0.2
4 125 0.4

NI 5114 Calibration Procedure |© National Instruments |9
5 125 1
6 125 2
7 125 4
8 125 10
9 125 20
10 125 40
11 20 0.04
12 20 0.1
13 20 0.2
14 20 0.4
15 20 1
16 20 2
17 20 4
18 20 10
19 20 20
20 20 40
Table 4. NI 5114 Input Parameters for Vertical Offset Accuracy
and Vertical Gain Accuracy Verification (Continued)
Iteration Max Input Frequency (MHz) Range

10 |ni.com |NI 5114 Calibration Procedure
Vertical Offset Accuracy
Complete the following steps to verify vertical offset accuracy of the NI 5114. You must verify
both channels with each iteration listed in Table 5.
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.
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:
NISCOPE_VAL_1_MEG_OHM
maxInputFrequency: The
Maximum Input Frequency
value in Table 5 for the current
iteration