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) as defined in the Ethernet-APL Data Test Specification v1.0 and the IEEE 802.3cg-2019 standard. 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) and power level measurements, Transmitter clock frequency, distortion and jitter measurements, Voltage Droop, PoDL / SPoE 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. Save signal captures and run the test report to automatically analyze pass/fail criteria for IEEE 802.3cg and Ethernet-APL Test Data Specification v1.0 and document with a data report.

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, performance testing on different twisted pair cable lengths and noise environments and compliance testing using the Ethernet-APL Worst Case Communication Channels for Trunk or Spur ports.

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

Includes Printable Reports

Features Include
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 from 1kHz to 300MHz
o Generate AWGN, alien crosstalk, impulse noise, RFI, Ripple Voltage with a Crest Factor > 5
o Wide dynamic range of AWGN from -70 dBm/Hz to -155 dBm/Hz in 0.1 dB increments*
o Import real world noise from capture card
o Receive Packet Error Rate Stress Test noise with Alien Crosstalk and Ripple Voltage Noise
o Generates sinusoidal 1Vpp 1MHz signal for transmitter distortion test
Digital Analyzer
o A/D Capture Card sample rate – 500 MS/s, 14-bit from 20kHz to 250MHz
o Capture, analyze and monitor live noise/interference on a single twisted pair cable
o Analyze in time and frequency domain
o Performs PSD mask verification and Tx Power level
o Perform Transmitter distortion, timing, jitter and droop measurements
o Testing on both sides of network simultaneously
o Generate 10Base-T1L 802.3cg and Ethernet-APL Compliance test report in PDF format
Applications
o IEEE 802.3cg-2019 and Ethernet-APL Data Test Specification v1.0 Compliance testing
o IEEE 802.3cg Section 146.5.5.3 Alien Crosstalk Noise Rejection
o Cable Tray “6 around 1” Alien Crosstalk
o Performance Testing
o Interoperability Testing
Integrate with Telebyte’s Model 4950 SPE Cable Emulator
o Test APL.146.2.1 – Receive Packet Error Rate Stress Test
-Alien Crosstalk
-Ripple Voltage if port is a power source or powered load

*when used with integrated differential mode noise injector in the model 4950

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 IEEE 802.3cg 146.5.5.3 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 over Data Line (PoDL / SPoE) noise, Power Line Communication (PLC) noise, Ripple Voltage 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 and the Ethernet-APL Port Profile and Data Test Specifications define the cable models for testing 10Base-T1L for both Trunk and Spur cable segments. Telebyte’s model 4950 (see separate datasheet) is a cable emulator that is fully compliant with the cable models in IEEE 802.3cg and Ethernet-APL standards. It 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.

IEEE 802.3cg Compliance Testing with the Model 4975

Power Spectral Density (PSD) and Power Level 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 and writes this data to the disk. An FFT algorithm is then employed to provide the frequency spectrum view of the saved data. 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 and the Transmit power level. The transmit power level is also verified to between -0.2dBm and 2.2dBm for the 1.0 Vpp operating mode and between 7.4dBm and 9.8dBm for the 2.4 Vpp mode. This requirement is defined in IEEE 802.3cg section 146.5.4.4 Transmitter Power Spectral Density (PSD).

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 MBd must have a short term variation of less than 0.10 ppm/second. The Transmit Voltage level must follow the operating mode of 1.0 Vpp or 2.4 Vpp. This requirement is defined in IEEE 802.3cg sections 146.5.4.3 Transmitter Timing Jitter, and 146.5.4.5 Transmit Clock Frequency.

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 peaks with voltages measured at 133.3ns and 800ns, respectively from the zero crossing. This requirement is defined in IEEE 802.3cg sections 146.5.4.1 Transmitter Output Voltage and 146.5.4.2 Transmitter Output Droop.

10Base-T1L 802.3cg 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.

Ethernet-APL Compliance Testing with the Model 4975

Power Spectral Density (PSD) and Power Level 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 and writes this data to the disk. An FFT algorithm is then employed to provide the frequency spectrum view of the saved data. 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 and the Transmit power level. The transmit power level is also verified to between -0.2dBm and 2.2dBm for the 1.0 Vpp operating mode and between 7.4dBm and 9.8dBm for the 2.4 Vpp mode. This requirement is defined in Ethernet-APL Test Data Specification v1.0 section Test.APL.146.1.4 Transmitter Power Spectral Density (PSD) and Power Level.

Transmitter Clock Frequency, Distortion 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 MBd must have a short-term variation of less than 0.10 ppm/second. The Transmit Voltage level must follow the operating mode of 1.0Vpp or 2.4Vpp. Power Sources and Powered Devices are expected to include circuitry to limit voltages especially intrinsically safe spur devices. To support PoDL/SPoE these components may cause distortion in the transmitter signal which must be tested to insure it is less than 50mV in amplitude. This requirement is defined in Ethernet-APL Test Data Specification v1.0 sections Test.APL.146.1.3 Transmitter Timing Jitter, Test.APL.146.1.5 Transmit Clock Frequency, and Test.APL.146.1.7 APL Transmitter Distortion.

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 peaks with voltages measured at 133.3ns and 800ns, respectively from the zero crossing. The Ethernet-APL Test Data Specification allows for a greater droop equal to 15% when a power coupling network is involved. This requirement is defined in Ethernet-APL Test Data Specification v1.0 sections Test.APL.146.1.1 Transmitter Output Voltage, and Test.APL.146.1.2 Transmitter Output Droop.

Ethernet-APL 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 Ethernet-APL Test Data Specification v1.0: Test.APL.146.1.1 Transmitter Output Voltage, Test.APL.146.1.2 Transmitter Output Droop, Test.APL.146.1.3 Transmitter Timing Jitter, Test.APL.146.1.4 Transmitter Power Spectral Density (PSD) and Power Level, Test.APL.146.1.5 Transmit Clock Frequency and Test.APL.146.1.7 APL Transmitter Distortion.

Report Examples

APL 146.1.2 Transmitter Output Droop
802.3cg 146.5.4.4 Transmitter Power Spectral Density (PSD)

Standards Based Testing and Customer Care

Software and Support Maintenance Contract

Telebyte values our customers and understands time is valuable. We believe your success is our success. We help you get started testing quickly by providing guidance on the setup and use of our software to produce valid test results.

Telebyte tracks the standards and updates the 4975 software* based on update releases and customer requests on a quarterly basis.

Included in the first year of ownership: We are pleased to include the 1-Year Software & Support Maintenance Contract with the purchase of Telebyte hardware and software*.

Available for purchase after the first year: Beginning on the first one-year anniversary of the date of purchase, the Annual Software & Support Maintenance Contract provides any software updates for the product* that are released during the term of the contract** as well as unlimited support via webinar, email or phone for the term of the contract.

*Model 4900-NS1 software and/or Model 4975-500 software
** One, two and three-year contracts available