Sources of Electrical Noise | Fluke DSP-2000, DSP-100 specs

DSP-100/2000

Users Manual

Noise

Electrical noise is unwanted electrical signals that alter the shape of the signals transmitted on a LAN cable. Figure 7-5 shows an example of how noise affects the shape of an electrical signal known as a sine wave. Signals that are severely distorted by noise can cause communication errors in a LAN.

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Figure 7-5. Sources of Electrical Noise

Electrical noise is generated by any device that uses or generates voltages that vary over time. Varying voltage generates a varying electromagnetic field, which transmits noise to nearby devices in the same way that a radio transmitter transmits signals to your radio. For example, fluorescent lights, which use 50 or 60 Hz ac (alternating current) power, continuously radiate a 50 or 60 Hz signal that can be received by nearby devices as electrical noise.

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Fluke DSP-2000, DSP-100 user manual Sources of Electrical Noise

Contents

DSP-100/2000 Limited Warranty & Limitation of Liability Table of Contents DSP-100/2000 Appendices DSP-100/2000 List of Tables Tests Run per Test Standard During an Autotest List of Figures Plot of NEXT, Attenuation, and the Resulting ACR Overview of Features Introduction DSP-100/2000 Standard Accessories Standard Accessories Using This Manual DSP-100/2000 Safety and Operational Information International Electrical Symbols DSP-100/2000 Quick Start Powering the Test ToolUsing the Menus Key Setup Setting Quick ConfigurationQuick Configuration Settings Description Press ! Choice Results within Accuracy Range Asterisk and Test Tool Accuracy Autotest on Twisted Pair Cable Horizontal Cross Connect Blocks Meters Getting Started Autotest on Coaxial Cable Autotest on Coaxial Cable Main Unit Features DSP-100 DSP-2000 Feature Main Unit Features Description Remote Features Standard and Smart Remote Features Remote Features Remote Connectors and Features Strap and Bail Rotary SwitchOff Autotest Single Test Monitor Setup Special Functions Turning On the Test ToolPrint Smart Remote Model DSP-100 Selecting a Language for Displays and Reports Performing a Self-Test Noise Test Configuring the Test ToolOvervoltage Test Controlling the Backlight Adjusting the Display Contrast Selecting a Power Line Filter Frequency Selecting an Average Cable Temperature Selecting a Test Standard and Cable Type Selecting a Conduit Setting Selecting a Length Unit Selecting a Numeric Format Setting the Date and Time Setting the Power-Down Timer Enabling or Disabling the Audible Tones Remote Lights, Messages, and Audible Tones Remote End Testing Smart Remote Ready Remote Communication Error Battery Status Battery Status Display Autotest Autotest Softkeys Smart Autotest Automatic Diagnostics Model DSP-2000 Link Performance Grade Result Headroom Automatic Diagnostics Model DSP-2000 Wire Map Test Autotest Results for Twisted Pair Cable Autotest Results for Twisted Pair Cable Resistance Length Propagation Delay and Delay Skew Characteristic Impedance Attenuation Items on the Attenuation Results Screen Description Gc10c.eps Next Test Items on the Next Results Screen Description Next Plot Screen Items on the Next Plot Screen Description ACR Items on the ACR Results Screen Description ACR Plot Screen Items on the ACR Plot Screen Description Return Loss RL Items on the RL Results Screen Description RL@REMOTE Model DSP-2000 Psnext Power Sum Next Model DSP-2000 Connector Autotest Results for Coaxial Cable Anomaly No Reflection Saving Autotest Results Gc15c.eps Automatically Incrementing the Cable Identification Name Autotest ReportIf Memory is Full Part of an Autotest Report for Twisted Pair 10. Autotest Report for Coaxial Cable DSP-100/2000 Running Individual Tests Single Tests for Twisted Pair Cable When to Use a Remote Unit Scanning Function Test Remote Requirements for Cable Tests Remote Unit Running a Single Test on Twisted Pair Cable Running Individual Tests TDX Analyzer Running the TDX Analyzer TDX Analyzer Results Items on the TDX Analyzer Results Screen TDX Analyzer Plot How to Terminate the Cable TDR Test Running the TDR Test on Twisted Pair Cable Running the TDR Test on Coaxial Cable TDR Plot Screen TDR Results ScreenItems on a TDR Results Screen Twisted Pair Results Single Test Results for Twisted Pair Cable Next and NEXT@REMOTE Wire MapImpedance Return Loss RL and RL@REMOTE Single Tests for Coaxial CableRunning a Single Test on Coaxial Cable Single Tests for Coaxial Cable Monitoring Network Activity Single Test Results for Coaxial Cable Monitoring Network Activity DSP-100/2000 Items on the Traffic Monitor Screen Description Monitoring Impulse Noise Identifying Hub Port ConnectionsChanging the Impulse Noise Threshold Running the Impulse Noise Test Use Dto highlight Impulse Noise on RJ45 Noise Test Results Determining Hub Port Capabilities Model DSP-2000Items on the Noise Monitor Screen Description Using the Tone Generator Model DSP-2000 Viewing and Printing Saved Reports Printing Test Reports Printer Interface Cable Configuring the Serial PortPrinting Viewing and Printing Saved Reports Printing Test Reports DSP-100/2000 If the Printer Does Not Respond Viewing, Renaming, and Deleting Test Reports Calibrations and Custom Test Standards Calibrating the Test Tool Connections for Self-Calibration DSP-2000 Shown NVP Calibration Use Dto highlight Determine Cable NVP Configuring a Custom Cable Page DSP-100/2000 Basic Cable Testing LAN Cable Construction Twisted Pair Cable Twisted Pair Cable Construction 568A Coaxial Cable Coaxial Cable Construction Attenuation of a Signal Attenuation Noise Sources of Electrical Noise Characteristic Impedance Minimizing Impedance Discontinuities Locating Next Problems Crosstalk and Near-End Crosstalk Next A TDX Analyzer Plot Basic Cable Testing Incorrect Wiring Split Pair Split Pairs and Next Minimizing Crosstalk Nominal Velocity of Propagation NVP NVP and Length Measurements Time Domain Reflectometry TDR NVP Calibration Reflections from Opens Short Reflections from Shorts Reflections from Other Discontinuities Cable Termination Interpreting the TDR Plot ACR Limit in dB Frequency in MHz Troubleshooting Basics Finding Cable Faults Identifying Cable Faults Likely Causes of Failure Test Failure Identifying Cable Faults Examples of Test Displays and Plots Identifying Cable Faults Test Failure Next test fails Impedance anomaly is Detected DSP-100/2000 Maintenance Cleaning and Storage Replacing the NiCad Battery Pack Removing the Battery in the Standard Remote Internal Lithium Backup Battery Removing the NiCad Battery Pack Service Center Repair If the Test Tool Fails Symptom 3 Test results appear to be incorrect Troubleshooting the Test Tool Symptom 1 Display is blankSymptom 2 Remote unit is not detected Symptom 6 Self calibration fails Replacement Parts Description Replacement PartsPart Number Self-Calibration Period SpecificationsService Center Calibration Period Compatibility with Remote Units Test Standards Cable Types TestedTime for Autotest Propagation Delay Test Specifications Propagation Delay TestLength Test Specifications Length Test DC Loop Resistance Next TDR Specifications for Cables 100m 328 ft TDX Analyzer Specifications for Cables 100m 328 ftReturn Loss Model DSP-2000 LAN Traffic Impulse NoiseModel DSP-100 LAN Traffic Serial Interface PC Interface Cable 25-pin ConnectorPC Interface Cable Connections Test Tool End DB9S female Power Environmental Requirements Operating Environment Specifications Input Ratings Certifications DimensionsWeight Memory Warranty RJ45 ConnectorDisplay DSP-100/2000 Appendices Page Using DSP-LINK Introduction Connecting to a PC Installing DSP-LINKPreparing for Data Transfer Configuring the Serial Ports Figure A-1. Connecting the Test Tool to a PC Communication Problems DSP-LINK Functions Detailed Test Data Quick Plot DSP-100/2000 Formatting Hints for Uploaded Reports Table A-3. Formats for Uploaded Reports Courier Point Size Getting Software Updates from Fluke Downloading New Test Standards Downloading New Software 10BaseT 10Base2100BaseTX Auto-Negotiation Baseband SignalingBroadband Signaling Bandwidth Collision CapacitanceChannel Crossed Pair Download CrosstalkCSV Data EIA 568A Horizontal Cross-Connect Hardware Flow ControlHorizontal Cabling Impedance Discontinuity Near-End Crosstalk Next Propagation DelayLink Pulse Packet Runt Packet Reversed PairRJ45 Screened Twisted Pair ScTP Terminator Split PairTDXä Token Ring XON/XOFF Flow Control DSP-100/2000 Tests Run per Test Standard During an Autotest Next Prop. Return Loss Delay2 Delay Skew2 Tests Run per Test Standard During an Autotest C TP-PMD Prop Delay2 Delay Skew2 Return Loss DSP-100/2000 Index DSP-LINK Next DSP-100/2000 Index DSP-100/2000 Manual Supplement Change #1 Wire Map Condition Wire Map Displays Displayed Schematic Description Wire map display showing an open on pair 1 Wire map display showing a split pair on pairs 1, 2 and 3 Change #3