TEKTRONIX VX4240 VXIbus protocol waveform digitizer/analyzer module

Falling time (AF) measures the time it takes for a signal to drop from 90% steady state to 10% steady state, and returns the maximum/minimum/average values

Return the maximum/minimum/average value and corresponding address of the part where the overshoot (AO) signal exceeds 100% steady-state value

Return the maximum/minimum/average value and corresponding address for the part of the down rush (AU) signal below 0% steady-state value

Find the maximum/minimum voltage values and corresponding memory addresses within the specified sample range (AX/AM)

Pulse width (AW/AZ) measures the duration of pulse high/low levels, supports absolute zero or floating reference points, and returns maximum/minimum/average values

(2) Frequency domain analysis function

Function Name Description

FFT analysis (AC) fast Fourier transform, supports voltage (V) or power (dBm) units, can return maximum amplitude and frequency, harmonic parameters, etc

FFT+Hanning Window (AH) FFT with Hanning Window to reduce spectral leakage, suitable for non periodic signals

FFT+Blackman Harris Window (AQ) FFT with Blackman Harris Window, further suppressing spectral leakage and achieving higher resolution

Total Harmonic Distortion (THD) calculates the amplitude ratio of the fundamental wave to the first 5 harmonics, in dBc (relative to the carrier wave)

Signal to Noise Ratio (SNR) is the ratio of the fundamental amplitude to the amplitude of all non harmonic noise, measured in dBc

The difference between the fundamental amplitude and the maximum amplitude of the spurious signal (noise or harmonic) in the non spurious dynamic range (SFDR), measured in dBc

(3) Statistical and mathematical analysis functions

Function Name Description

Calculate the average voltage value within a specified sample range using the mean (AA)

The true RMS value (AT) calculates the true effective value of a signal (square root mean square), reflecting the actual power of the signal

The standard deviation (AS) reflects the degree of dispersion of sample data and can simultaneously return the proportion of data within the ± N σ range (N=1-9)

Integral (AI) calculation of the area under the signal curve (accumulated sample values multiplied by the sampling interval)

Differential (AD) calculates the difference between consecutive sample points, reflecting the rate of signal change

Cycle/Frequency/Duty Cycle (AY/AW/AZ) is based on zero crossing detection to calculate the signal cycle, frequency, and high-level duty cycle

(4) Recording and special analysis functions

Function Name Description

Record operation (AG) performs average, difference, and maximum/minimum value calculations on multiple records to generate new records

Single frequency DFT (AL) is a discrete Fourier transform for a specified frequency that returns amplitude (RMS) and phase (radians), supporting single/double precision

Zero crossing time (AZ) detects the zero crossing time of the signal, calculates parameters such as cycle and duty cycle, and the reference point is absolute zero

Installation and Operation Guide

1. Preparation and requirements before installation

(1) Tools and Environment

Essential tool: Phillips screwdriver.

Environmental requirements: The mainframe should provide sufficient heat dissipation (2.7 liters/second airflow, pressure drop of 0.19 mm H ₂ O, module temperature rise<10 ° C), operating temperature of 0 ° C~55 ° C, storage temperature of -40 ° C~85 ° C, relative humidity<75% (non condensing, 31 ° C~40 ° C).

(2) Switch settings (critical configuration, incorrect settings will cause module failure)

Description of switch name and position requirements

Logical address switch (S080) 1-255 (FFh is dynamically configured) base address calculation formula: [(64d × XYh)+49152d], it is recommended to match the slot number

The interrupt level switch (S081) 1-7 (0/8/9 disable interrupts) needs to match the interrupt handling level of the system controller

The Halt switch (S084) must be set to ON, otherwise the module cannot respond to VXIbus resource manager commands properly

The Bootstrap switch (S56) is set to OFF for factory testing purposes, and users do not need to adjust it

The memory size switch (S083) is preset by the factory and cannot be adjusted by oneself. It matches the hardware configuration of the memory

(3) Installation steps

Record the revised version of the module, serial number (top shield label), and switch settings, and fill in the installation checklist.

Confirm that the power supply of the host rack is turned off, and insert the module into any C/D size slot except for slot 0 (the D-size host rack should be adapted according to the host rack manual).

Tighten the module fixing screws to ensure that the front panel is grounded and avoid the risk of electric shock.

Connecting cables: The BNC interface uses RG58 coaxial cable to connect the device under test (UUT), while the DB25 interface can use CDS 73A-742P shielded connectors.

Check the overhead idle slot of the host: it needs to be covered with a blank panel to ensure heat dissipation; If there is a vacant slot on the left side of the module, the VME daisy chain jumper needs to be installed according to the host rack manual.