Telebyte Model 4975 Noise Generator and Analyzer for testing Single Pair Ethernet (SPE) including PoDL.

Model 4975
Noise Generator & Analyzer

Datasheet

The Telebyte 4975 SPE Noise Generator & Analyzer is a multi-function test instrument designed specifically for testing Single Pair Ethernet (SPE). This specialized instrument can be used to test a wide range of applications and features such as noise generation (including background and impulsive noise), noise capture to replicate field environments in the lab, Power Spectral Density (PSD) measurements, Transmitter clock frequency and jitter measurements, Voltage and PoDL measurements and more.   

This physical layer compliance test solution ensures interoperability between different designs and applications from hardware vendors. It can be configured with arbitrary waveform generator (AWG) cards, noise generation software, an A/D capture card, digital analysis software to emulate a storage oscilloscope and FFT Spectrum Analyzer, high-impedance differential mode probes and more.

When the Model 4975 SPE Noise Generator & Analyzer is used with the Telebyte Model 4950 SPE Cable Emulator (see separate datasheet), the test suite can be used for multi-vendor interoperability and performance testing on different twisted pair cable lengths and noise environments. 

See this product being used in Telebyte’s Network Topology Diagram

Includes Printable Reports

Features Include
Bandwidth up to 300 MHz
Expandable, Modular Design
o Portable Industrial Computer holds up to 4 PCIe cards (combination of AWG cards and/or capture card)
o Purchase only those components needed for specific requirement
Noise Generation
o Arbitrary Wave Form (AWG) sample rate – 625 MS/s, 16-bit
o Generate AWGN, crosstalk, impulse noise, RFI
o Generate AWGN from -70 dBm/Hz to -155 dBm/Hz in 0.1 dB increments
o Import real world noise from capture card
Digital Analyzer
o A/D Capture Card sample rate – 500 MS/s, 14-bit
o Capture, analyze and monitor live noise/interference
o Analyze in time and frequency domain
o Performs PSD mask verification
o Perform timing, jitter and droop measurements
o Testing on both sides of network simultaneously
o Generate test reports in PDF and Word formats
Applications
o IEEE 802.3 cg Compliance testing
o Performance Testing
o Interoperability Testing
Integrate with Telebyte’s Model 4950 SPE Cable Emulator

Noise Generation
User-friendly configuration software allows the user to select and build impairment models common to an Industrial Ethernet implementation. The 4975 can generate a wide variety of interferences including background Gaussian noise which may be used for Alien Crosstalk Noise Rejection, high frequency impulse noise from the AC electrical loads (REIN) and other types of impulsive noise, FM radio, Broadcast TV, Spark Plug Ignition noise, Power Line Communication (PLC) noise, Reverse Power Feed (RPF) noise and more. In addition, user-defined files in several formats (such as MATLAB, CSV and Excel) may be imported.

Telebyte Model 4975 screenshot showing noise capture. Used to replicate noise environments during lab testing.

Noise Capture
It is vital to test link performance in noisy conditions such as those found in factory environments with harsh EMC radiated noise. The effects of real-world noise environments on the twisted pair (including impulse noise, RFI, inductive noise, and background noise floor) can be captured, recorded and played back using the noise generation function of the 4975 to replicate different noise environments during lab testing. 

Cable Emulation
IEEE 802.3cg defines the cable models for testing 10Base-T1L. Telebyte’s model 4950 (see separate datasheet) is a cable emulator that is fully compliant with the cable models in IEEE 802.3cg and includes integrated differential model noise injectors at the input and output of the cable. Testing with the 4950 cable emulator and the noise generator function of the 4975 provides a powerful tool for gaining insight into the performance of 10Base-T1L network equipment.  

Power Spectral Density (PSD) Measurement
Power Spectral Density is a frequency domain measurement that typically requires a spectrum analyzer. The 4975 uses a 14-bit analog-to-digital converter (ADC) that samples at 500 MS/s in the time domain. An FFT algorithm is then employed to provide the frequency spectrum view. The computed PSD is then compared with the specification by using lower and upper masks to arrive at the result for both the 2.4V and 1.0V peak to peak modes. The DUT is set in Test Mode 3 for the PSD measurement.

Transmitter Clock Frequency and Jitter Measurements
Transmitter output voltage, clock frequency, and timing jitter are measured with the DUT in Test Mode 1. The symbol to symbol jitter must be less than +/- 10 ns and the transmit signal clock and receiver frequency tolerance at 7.5 Md must be +/- 50 ppm.

Droop Measurement
The Transmitter Output Voltage droop measurements are performed with the DUT in Test Mode 2 using the correct load termination of 100 ohms +/- 0.1%. The maximum allowed droop is 10% for both the positive and negative voltage with respect to the initial peak.

Telebyte 10BASE-T1L Compliance Test Report.

10Base-T1L Compliance Test Report
The test measurements are captured by the 4975, stored to the system data storage drive and post processed. The measurements are analyzed and compiled in a pass/fail report outputted in a pdf file with numerical data and graphs. The report includes the following sections from the IEEE 802.3cg test specification: 146.5.4.1 Transmitter Output Voltage, 146.5.4.2 Transmitter Output Droop, 146.5.4.3 Transmitter Timing Jitter, 146.5.4.4 Transmitter Power Spectral Density (PSD) and 146.5.4.5  Transmit Clock Frequency.