background image

NI PXIe-5624R Calibration Procedure

|

© National Instruments

|

9

Self-Calibrating the NI 5624R

Allow a 20 minute warm-up time before you begin self-calibration.

Note

The warm-up time begins after the PXI Express chassis is powered on and the 

operating system completely loads.

The NI 5624R includes precise internal circuits and references used during self-calibration to 
adjust for any errors caused by short-term fluctuations in the environment. It is important that 
you perform a self-calibration function to validate the specifications listed in the next section. 

You can perform the self-calibration through Measurement & Automation Explorer (MAX) or 
programmatically using LabVIEW.

Self-Calibrating Using MAX

To initiate self-calibration in MAX, complete the following steps:
1.

Disconnect or disable any AC inputs to the digitizer.

2.

Launch MAX.

3.

Expand 

My System»Devices and Interfaces»PXI System

.

4.

Select the device that you want to calibrate.

5.

Initiate self-calibration using one of the following methods:

Click 

Self-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.

Self-calibration takes approximately 1 minute to complete.

Self-Calibrating Using LabVIEW

To initiate self-calibration using LabVIEW, complete the following steps:
1.

Disconnect or disable any AC inputs to the digitizer.

2.

Use the Self-Calibrate VI located at 

FPGA Interface»Software Designed Instruments»

IF Digitizer»Calibration

 to initiate self-calibration.

Self calibration takes approximately 1 minute to complete.

As-Found and As-Left Limits

The as-found limits are the published specifications for the NI 5624R. NI uses these limits to 
determine whether the NI 5624R meets the device specifications when it is received for 
calibration.

The as-left limits are equal to the published NI specifications for the NI 5624R, less guard bands 
for the measurement uncertainty, temperature drift, and drift over time. NI uses these limits to 
ensure that the NI 5624R meets the published specifications over its calibration interval.

Summary of Contents for 5624R

Page 1: ...PGA converts data from the ADC into quadrature I Q data This DSP shifts the frequency of decimates equalizes and calibrates the data before storing it into DRAM Use Interactive Spectrum Acquisition Ho...

Page 2: ...oftware from ni com downloads Documentation You might find the following documentation helpful as you perform the calibration procedure NI PXIe 5624R Getting Started Guide NI IF Digitizers Help NI PXI...

Page 3: ...for this procedure Verifying absolute amplitude accuracy Adjusting internal frequency reference B22 option needed for this procedure Adjusting absolute amplitude accuracy Frequency range 4 MHz to 2 00...

Page 4: ...adapter Huber Suhner 31_3 SMA 50 1 1 _UE or Fairview Microwave SM4236 Test system characterization Frequency range DC to 2 GHz Impedance 50 Return loss 23 dB 3 5 mm m to 3 5 mm m adapter Huber Suhner...

Page 5: ...each verification procedure insert a delay between configuring all devices and acquiring the measurement Adjust this delay depending on the instruments used but make sure it is at least 5 000 ms for t...

Page 6: ...e verification and adjustment procedures use test points from 5 MHz to 2 005 GHz in 5 MHz steps for the splitter balance characterization Frequencies in which harmonics alias on the fundamental freque...

Page 7: ...rrection function 7 Use the power sensor to measure the power at the frequency from step 6 8 Repeat steps 5 through 7 by updating the signal generator frequency from 5 MHz to 2 005 GHz in 5 MHz steps...

Page 8: ...e signal generator frequency from 5 MHz to 2 005 GHz in 5 MHz steps Record the resulting measurements as splitter output 1 power Each frequency should have a corresponding value 16 Calculate the split...

Page 9: ...ate self calibration using one of the following methods Click Self Calibrate in the upper right corner of MAX Right click the name of the device in the MAX configuration tree and select Self Calibrate...

Page 10: ...ference using a signal generator Use digitizer mode of the NI 5624R Use Interactive IF Acquisition Without DSP Host vi in the Multirecord Acquisition sample project as a starting point 1 Connect the s...

Page 11: ...gle Tone Information vi 5 Calculate the deviation using the following equation 6 Compare the value determined in step 5 to the verification test limits in the following table where initial accuracy 20...

Page 12: ...e across 400 MHz of bandwidth for each center frequency is measured This procedure requires the test setup and data collected in the Characterizing Power Splitter Balance section Characterize the powe...

Page 13: ...front panel connector The following figure illustrates the complete hardware setup Figure 4 Absolute Amplitude Accuracy Verification Cabling Diagram 1 Power Sensor 2 SMA m to N f Adapter 3 Power Spli...

Page 14: ...sult as measured input power Note Power sensor readings are in dBm not watts 9 Calculate the corrected input power using the following equation corrected input power measured input power splitter bala...

Page 15: ...R flash memory Successfully complete all required verifications or successfully complete reverification following adjustment prior to updating the calibration date and time on the NI 5624R Complete th...

Page 16: ...panel connector to the NI 5624R IF IN front panel connector using an SMA m to SMA m cable The following figure illustrates the hardware setup Figure 5 Internal Frequency Reference Adjustment Cabling...

Page 17: ...he power splitter balance characterization data for the correct frequency as the following frequencies are excluded from the adjustment procedure due to harmonics aliasing back on to the fundamental a...

Page 18: ...that the NI 5624R and the signal generator share a common reference The following steps assume you have connected the signal generator reference frequency REF OUT to the NI 5624R REF IN connector 6 C...

Page 19: ...plitter output 1 of the power splitter using the power sensor Record this value as the measured input power 12 Calculate the corrected input power using the following equation corrected input power me...

Page 20: ...NI Refer to the Worldwide Support and Services section for information about support resources or service requests Worldwide Support and Services The National Instruments website is your complete reso...

Reviews: