Reflections from Opens, Short | Fluke DSP-2000, DSP-100 specs

DSP-100/2000

Users Manual

Reflections from Opens

An open, or break, in the cable represents an abrupt increase in the cable’s impedance. The impedance of an open is nearly infinite. In an open cable, a signal’s energy is not dissipated by a terminating impedance, so the signal bounces back towards the source. This reflection appears at the source with the same amplitude and polarity as the original signal, as shown on the next page in Figure 7-9. By measuring the amount of time taken for the reflected pulse to return, the test tool can determine the location of the open in the cable.

	OFF	AUTO TEST	TEST	SINGLE	EXIT	FAULT INFO	TEST	12	DSP
				MONITOR	ENTER			3	-2000 CABLE
SMART REMOTE	SPECIAL FUNCTIONS	PRINT		SETUP			SAVE	4	ANALYZER

	OFF	AUTO TEST	TEST	SINGLE	EXIT	FAULT INFO	TEST	12	DSP
				MONITOR	ENTER			3	-2000 CABLE
SMART REMOTE	SPECIAL FUNCTIONS	PRINT		SETUP			SAVE	4	ANALYZER

Cable

End of Fault

Transmitted Pulse

Open

Reflected Pulse

Transmitted Pulse

Short

Reflected Pulse

	OFF	AUTO TEST	TEST	SINGLE	EXIT	FAULT INFO	TEST	12	DSP
				MONITOR	ENTER			3	-2000 CABLE
SMART REMOTE	SPECIAL FUNCTIONS	PRINT		SETUP			SAVE	4	ANALYZER

Transmitted Pulse

No Reflected Pulse

Terminator

(Matches cable characteristic impedance)

gc35f.eps

Figure 7-9. Signals Reflected from an Open, Shorted, and Terminated Cable

7-16

Image 128

Fluke DSP-2000, DSP-100 user manual Reflections from Opens, Short

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 Powering the Test Tool Using the MenusQuick Start Key Quick Configuration Settings Description Quick ConfigurationSetup Setting 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 Off Rotary SwitchStrap and Bail Autotest Single Test Monitor Setup Turning On the Test Tool PrintSpecial Functions Smart Remote Model DSP-100 Selecting a Language for Displays and Reports Performing a Self-Test Configuring the Test Tool Overvoltage TestNoise 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 If Memory is Full Autotest ReportAutomatically Incrementing the Cable Identification Name 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 Items on a TDR Results Screen Twisted Pair Results TDR Results ScreenTDR Plot Screen Single Test Results for Twisted Pair Cable Impedance Wire MapNext and NEXT@REMOTE Running a Single Test on Coaxial Cable Single Tests for Coaxial CableReturn Loss RL and RL@REMOTE 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 Changing the Impulse Noise Threshold Identifying Hub Port ConnectionsMonitoring Impulse Noise Running the Impulse Noise Test Use Dto highlight Impulse Noise on RJ45 Items on the Noise Monitor Screen Description Determining Hub Port Capabilities Model DSP-2000Noise Test Results Using the Tone Generator Model DSP-2000 Viewing and Printing Saved Reports Printing Test Reports Printing Configuring the Serial PortPrinter Interface Cable 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 Troubleshooting the Test Tool Symptom 1 Display is blank Symptom 2 Remote unit is not detectedSymptom 3 Test results appear to be incorrect Symptom 6 Self calibration fails Part Number Replacement PartsReplacement Parts Description Specifications Service Center Calibration PeriodSelf-Calibration Period Compatibility with Remote Units Time for Autotest Cable Types TestedTest Standards Propagation Delay Test Length Test SpecificationsPropagation Delay Test Specifications Length Test DC Loop Resistance Next Return Loss TDX Analyzer Specifications for Cables 100m 328 ftTDR Specifications for Cables 100m 328 ft Impulse Noise Model DSP-100 LAN TrafficModel DSP-2000 LAN Traffic Serial Interface PC Interface Cable Connections Test Tool End DB9S female 25-pin ConnectorPC Interface Cable Power Environmental Requirements Operating Environment Specifications Input Ratings Dimensions WeightCertifications Memory Display RJ45 ConnectorWarranty DSP-100/2000 Appendices Page Using DSP-LINK Introduction Preparing for Data Transfer Installing DSP-LINKConnecting to a PC 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 100BaseTX 10Base210BaseT Baseband Signaling Broadband SignalingAuto-Negotiation Bandwidth Capacitance ChannelCollision Crossed Pair Crosstalk CSV DataDownload EIA 568A Hardware Flow Control Horizontal CablingHorizontal Cross-Connect Impedance Discontinuity Propagation Delay Link PulseNear-End Crosstalk Next Packet Reversed Pair RJ45Runt Packet Screened Twisted Pair ScTP Split Pair TDXäTerminator 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