National Instruments PXIe-5185, PXIe-5186 User Manual
CALIBRATION PROCEDURE
PXIe-5185/5186
This document contains information for calibrating National Instruments PXIe-5185/5186
digitizers. The PXIe-5185/5186 digitizers were developed jointly between Tektronix and
National Instruments. The devices use Tektronix, Enabling Technology
™
to deliver wide analog
bandwidth and high-speed sampling on the National Instruments Synchronization and Memory
Core (SMC) technology with TClk synchronization.
For more information on calibration, visit
ni.com/calibration.
Contents
50 Ω and 1 MΩ Devices ...........................................................................................................2
Software Requirements............................................................................................................. 2
Related Documentation ............................................................................................................2
Password ..................................................................................................................................3
Calibration Interval...................................................................................................................3
Test Equipment.........................................................................................................................3
Test Conditions.........................................................................................................................5
Calibration Procedures .............................................................................................................6
Initial Setup....................................................................................................................... 6
Self-Calibration ................................................................................................................6
MAX......................................................................................................................... 7
NI-SCOPE Soft Front Panel ..................................................................................... 7
NI-SCOPE ................................................................................................................ 7
External Calibration.......................................................................................................... 7
Test System Characterization ........................................................................................... 7
Zeroing the Power Sensor......................................................................................... 8
Characterizing Power Splitter Amplitude Imbalance............................................... 8
Verification....................................................................................................................... 14
Verifying DC and Programmable Vertical Offset Accuracy.................................... 14
Verifying 50 Ω AC Amplitude Accuracy and Bandwidth .......................................17
Verifying 1 MΩ AC Amplitude Accuracy and Bandwidth...................................... 20
Verifying Timebase Accuracy.................................................................................. 23
Adjustment........................................................................................................................ 23
Worldwide Support and Services ............................................................................................. 29
2 | ni.com | PXIe-5185/5186 Calibration Procedure
50 Ω and 1 MΩ Devices
Early versions of the PXIe-5185/5186 support only 50 Ω input impedance. Check the part
number of your device to see what input impedance is supported by your device:
• PXIe-5185 module part numbers 199363x-0zL and PXIe-5186 module part numbers
193537x-0zL (where x is any letter and z is any number) only support 50 Ω input
impedance. These devices require NI-SCOPE 3.8.7 or later.
• PXIe-5185 module part numbers 152962x-0zL and PXIe-5186 module part numbers
152961x-0zL (where x is any letter and z is any number) support both 50 Ωand 1 MΩ input
impedance. These devices require NI-SCOPE 3.9.6 or later.
50 Ωdevices need to be tested for only 50 Ωinput impedance because they have no 1 MΩ input.
Software Requirements
Calibrating the PXIe-5185/5186 requires installing the NI-SCOPE instrument driver on the
calibration system. Refer to the 50 Ω and 1 MΩ Devices section to see which driver version your
device requires. You can download the NI-SCOPE instrument driver from the NI website at
ni.com/downloads/drivers. NI-SCOPE supports programming a self-calibration and an
external calibration in multiple application development environments (ADEs). When you
install NI-SCOPE, you need to install support for only the ADE that you intend to use.
LabVIEW support is in the
niScope.llb file, and all calibration functions appear in the
NI-SCOPE Calibration palette. For LabWindows
™
/CVI™ users, the NI-SCOPE function panel,
niScope.fp, provides access to the available functions.
For the locations of files you may need to calibrate your device, refer to the NI-SCOPE Readme,
which is available on the NI-SCOPE media.
Related Documentation
For information about NI-SCOPE and the PXIe-5185/5186, consult the following documents:
• NI High-Speed Digitizers Getting Started Guide—provides instructions for installing and
configuring the PXIe-5185/5186.
• NI High-Speed Digitizers Help—includes detailed information about the PXIe-5185/5186
and NI-SCOPE VIs and functions and information about creating applications using
NI-SCOPE.
• PXIe-5185 Specifications—provides the published specification values for the PXIe-5185.
• PXIe-5186 Specifications—provides the published specification values for the PXIe-5186.
These documents are installed with NI-SCOPE. You can also find the latest versions of the
documentation at
ni.com/manuals.
PXIe-5185/5186 Calibration Procedure | © National Instruments | 3
Password
The default calibration password is NI.
Calibration Interval
NI recommends a calibration interval of one year to ensure the warranted specifications for the
PXIe-5185/5186 are met.
Test Equipment
National Instruments recommends that you use the equipment in Table 1 for calibrating the
PXIe-5185/5186. If you do not have the recommended instruments, use these specifications to
select a substitute calibration standard.
Table 1. PXIe-5185/5186 Test Equipment
Equipment
Recommended
Model
Requirements
Oscilloscope
calibrator
Fluke 9500B/3200 DC Output Range: 2 V to -2 V into 50 Ω,
6.5V to - 6.5 V into 1 MΩ
DC Voltage Accuracy: DC ±0.3% of output
into 50 Ω and 1 MΩ
Leveled Sine Wave Amplitude Range:
0.9 V
pk-pk
into 50 Ω
Leveled Sine Wave Frequency Accuracy:
±4 ppm
Square Wave: 8.0 V
pk-pk
at 100 kHz
into 1 MΩ
3.2 GHz output
module
Fluke 9530 Active
Head
Power sensor Rohde & Schwarz
NRP-Z91
Range: -26 dBm to 10 dBm
Frequency range: 50 kHz to 5.0 GHz
Absolute power accuracy:
• <0.048 dB at 50 kHz
• <0.063 dB at 5.0 GHz
Relative power accuracy:
• <0.022 dB at 50 kHz
• <0.031 dB for frequencies > 50 kHz and
< 5.0 GHz
VSWR: <1.11
4 | ni.com | PXIe-5185/5186 Calibration Procedure
Signal generator Rohde & Schwarz
SMA100A
Frequency range: 50 kHz to 5.0 GHz
Amplitude range: -20 dBm to 16 dBm
Harmonics: <-30 dBc
Power splitter Aeroflex/Weinschel Frequency range: 50 kHz to 5.0 GHz
VSWR: <1.1
Amplitude tracking: <0.5 dB
50 Ω BNC
terminator (f)
Fairview Microwave
ST3B-F
Frequency range: DC to 0.5 GHz
VSWR: <1.2
Impedance: 50 Ω
50 Ω SMA
terminator (f)
Fairview Microwave
ST1852F
Frequency range: DC to 5.0 GHz
VSWR: <1.1
Impedance: 50 Ω
SMA (m)-toSMA (m) cable
— Frequency range: DC to 5.0 GHz
VSWR: <1.1
Length: ≤1 meter
SMA (m)-toBNC (f)
Fairview Microwave
SM4723
Frequency range: DC to 100 kHz
Impedance: 50 Ω
SMA (f)-toN (m) adapter
Fairview Microwave
SM4226
Frequency range: DC to 5.0 GHz
VSWR: <1.05
Impedance: 50 Ω
SMA (f)-to-N (f)
adapter
Fairview Microwave
SM4236
Frequency range: DC to 5.0 GHz
VSWR: <1.15
Impedance: 50 Ω
SMA (m)-toSMA (m)
adapter (×2)
Fairview Microwave
SM4960
Frequency range: DC to 5.0 GHz
VSWR: <1.1
Impedance: 50 Ω
Table 1. PXIe-5185/5186 Test Equipment (Continued)
Equipment
Recommended
Model
Requirements
PXIe-5185/5186 Calibration Procedure | © National Instruments | 5
Test Conditions
Follow these guidelines to optimize the equipment and the environment during calibration:
• Keep connections to the device as short as possible. 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.
• Use shielded copper wire for all cable connections to the device. Use twisted-pairs wire to
eliminate noise and thermal offsets.
• Maintain an ambient temperature of 23 ±3 °C. The device temperature will be greater than
the ambient temperature.
• Keep relative humidity below 80%.
• Allow a warm up time of at least 25 minutes to ensure that the measurement circuitry is at
a stable operating temperature.
• Ensure that the PXI Express chassis fan speed is set to HIGH, that the fan filters are clean
if present, and that 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.
• Plug the chassis/PC and the calibrator into the same power strip to avoid ground loops.
BNC (f)-toN (f) adapter
Fairview Microwave
SM3526
Frequency range: DC to 0.5 GHz
VSWR: <1.2
Impedance: 50 Ω
SMA (m)-toBNC (m)
adapter (×2)
Fairview Microwave
SM4716
Frequency range: DC to 0.5 GHz
VSWR: <1.3
Impedance: 50 Ω
BNC
feed-through
terminator
Fairview Microwave
ST0150
Frequency range: DC to 0.5 GHz
VSWR:
• <1.1 at 100 MHz
• <1.25 at 500 MHz
Impedance: 50 Ω
PXI Express
Chassis
Any NI PXI Express
chassis that meets the
requirements
100 MHz reference clock for PXI Express
slots with an accuracy of ±25ppm
Table 1. PXIe-5185/5186 Test Equipment (Continued)
Equipment
Recommended
Model
Requirements
6 | ni.com | PXIe-5185/5186 Calibration Procedure
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. Re-verification—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 PXIe-5185/5186 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 25 minute warm-up period before you begin self-calibration.
Self-calibration can be initiated from MAX, NI-SCOPE Soft Front Panel (SFP), or NI-SCOPE.
MAX
To initiate self-calibration from MAX, complete the following steps:
1. Launch MAX.
2. Select My System»Devices and Interfaces.
3. Select the device that you want to calibrate.
4. Initiate self-calibration in one of the following ways:
• Click Self-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 NI-SCOPE SFP, complete the following steps:
1. Launch the NI-SCOPE SFP.
PXIe-5185/5186 Calibration Procedure | © National Instruments | 7
2. Select the device you want to calibrate using the Device Configuration dialog box by
selecting Edit»Device Configuration.
3. Launch the Calibration dialog box by selecting Utility»Self Calibration.
4. Click OK to begin self-calibration.
NI-SCOPE
To self-calibrate the digitizer programmatically using NI-SCOPE, complete the following steps:
1. Open a session and obtain a session handle using the niScope Initialize VI.
2. Self-calibrate the digitizer using niScope Cal Self Calibrate VI.
3. End the session using the niScope Close VI.
External Calibration
External calibration involves both verification and adjustment. Verification is the process of
testing the device to ensure that it is within certain specifications. You can use verification to
ensure that the adjustment process was successful.
Adjustment is the process of measuring and compensating for device performance to improve
the input accuracy. Performing an adjustment updates the calibration date, resetting the
calibration interval. The device is warranted to meet or exceed its published specifications for
the duration of the calibration interval.
Test System Characterization
The following procedures characterize the test equipment used during verification.
Caution The connectors on the device under test (DUT) and test equipment are
fragile. Perform the steps in these procedures with care to prevent damaging any
DUTs or test equipment.
Zeroing the Power Sensor
1. Ensure that the power sensor is not connected to any signals.
2. Zero the power sensor using the built-in function, according to the power sensor
documentation.
Characterizing Power Splitter Amplitude Imbalance
These procedures characterize the amplitude imbalance of the two output ports of the power
splitter over a range of frequencies. You must perform separate characterizations for the two
different connector types used in verification.
8 | ni.com | PXIe-5185/5186 Calibration Procedure
SMA Adapters
This procedure characterizes the power splitter imbalance when using SMA adapters. The
results of this characterization are later used as a correction in the Verifying 50 Ω AC Amplitude
Accuracy and Bandwidth procedure.
1. Connect the SMA (f)-to-N (f) adapter to the power sensor. Refer to this assembly as the
power sensor.
2. Zero the power sensor as described in the Zeroing the Power Sensor section.
3. Connect the RF OUT connector of the signal generator to the input port of the power splitter
using an SMA (f)-to-N (m) adapter and an SMA (m)-to-SMA (m) cable.
4. Connect an SMA (m)-to-SMA (m) adapter to one of the power splitter output ports. Refer
to this assembly as splitter output 1.
5. Connect the 50 Ω SMA terminator (f) to splitter output 1.
6. Connect the other SMA (m)-to-SMA (m) adapter to the other output port of the power
splitter. Refer to this assembly as splitter output 2.
Table 2. Power Splitter Characterization for SMA Configuration
Configuration
Test Point
Impedance
Frequency
(MHz)
Amplitude (dBm)
1 50 Ω 0.05 -0.5
2 50 Ω
(PXIe-5185 only)
3000 -0.5
3 50 Ω
(PXIe-5186 only)
5000 -0.5
PXIe-5185/5186 Calibration Procedure | © National Instruments | 9
7. Connect the power sensor to splitter output 2.
The following figure illustrates the hardware setup.
Figure 1. Connection Diagram for Measuring at Splitter Output 2 (SMA)
8. Configure the signal generator to generate a sine waveform with the following
characteristics:
• Frequency: the Test Point Frequency value from Table 2
• Amplitude level: the Test Point Amplitude value from Table 2
9. Configure the power sensor to correct for the Test Point Frequency value using the power
sensor frequency correction function.
10. Use the power sensor to measure the power in dBm.
11. Repeat steps 8 through 10 for each configuration in Table 2, recording each result as
splitter output 2 power, where each configuration has a corresponding value.
12. Disconnect the power sensor and 50 Ω SMA terminator (f) from splitter output 2 and
splitter output 1.
1 Signal Generator
2 SMA (f)-to-N (m) Adapter
3 SMA (m)-to-SMA (m) Cable
4 50 ΩSMA Terminator (f)
5 SMA (m)-to-SMA (m) Adapter
6 Power Splitter
7 SMA (f)-to-N (f) Adapter
8 Power Sensor
1
64 5
3
7
8
2
5
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