Black Box May-95, ME758C-RJ45, ME759C-RJ45, ME759C-RJ11 manual Diagnostic Testing Using the Error LED

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CHAPTER 5: Operation and Diagnostics

5.2 Diagnostic Testing Using the Error LED

5.2.1TESTING CABLE QUALITY

NOTE

The Error LED’s circuitry is designed to detect line quality across 4-wire twisted-pair cable only, and might not function properly with 2-wire cable.

If there is any question as to the quality of your line, we recommend the following test:

1.Disconnect both local and remote modems from their attached RS-232 DTE devices. Make sure the red TD, RD, and RTS LEDs are all lit.

2.Set the input impedance of both modems to 200 ohms by setting switch S3 position 1 “On” and S3 position 2 “Off.”

3.Set the data rate on both modems to 9.6 kbps by setting switch S1 position 1 “On,” S1 position 2 “Off,” S1 position 3 “Off,” and S1 position 4 “On.”

4.On the local modem, set carrier control for “Constantly on” by setting switch S1 position 8 “Off.”

5.On the remote modem, set carrier control to “Controlled by RTS” by setting switch S1 position 8 to “On.”

6.Move both front-panel toggle switches to the center (neutral) position. (The Test LED should not light.)

7.Connect both modems to the 4-wire twisted-pair cable to be tested. (See Section 4.5 for pinouts and guidelines for this type of cable.)

8.Here’s how to interpret the results:

A.If the quality of the line is good, neither modem’s Error LED will light. The local modem’s red CD LED will light, and the remote modem’s green CD LED will light.

B.If there is flat satin cable in the line somewhere between the modems, the local modem’s Error LED and green CD LED will both light. On the remote modem, the remote modem’s green CD LED will light, but the Error LED will stay dark.

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Contents Multi-Function LD Cards FCC Statements MULTI-FUNCTION LD Card NOM Statements Contents Specifications Connectors IndicatorsDiagnostics Power TemperatureWeight FuseOverview FeaturesIntroduction Introduction Setting the Switches on the Main Module Main-module switchesOn and OFF settings of the DIP switches Switch S1 SummaryS1 Position 7 Protocol S1 Positions 1 through 4 Data-Rate SettingS1 Positions 5 and 6 Clock Source S1 Position 8 Carrier-Control Method Switch S2 SummaryS2 Position 2 2-Wire vs -Wire Operation S2 Position 3 V.52 and V.54 Diagnostic Testing S2 Positions 4 and 5 RTS/CTS DelayS2-6 Signaling-Rate Range S2-7 and S2-8 Word LengthSwitch S3 Summary S3-1 and S3-2 Input ImpedanceRecommended Impedance Settings S3-4 Mode SelectionS3-5 DTE RS-232 Initiation of Local Loopback Test S3-6 DTE RS-232 Initiation of Remote Loopback TestSetting the Jumpers on the Interface Module S3-7 and S3-8 Antistream ControlFour interface modules Jumper locations Summary of Interface-Module Jumper Functions Line Interface Line Shield Connection to Frame Ground JB2Serial Interface Signal Ground and Frame Ground JB4 JB5Installation MicroRacks An OverviewMicroRacks’ Power Supply Installing the Multi-Function LD Card in the MicroRack Pinout of the 10-Pin RJ Interface RS-232 Serial Cables and ConnectorsPinout of the RS-232 Interface Modem-to-Modem Line Cables and Connectors Line-Cable Pinouts AT&T standard modular color codesTwo-pair star wiring for host and slave Cards Multipoint ApplicationsOperation and Diagnostics Status LEDsRTS and CD Indicators Diagnostic Testing Using the Error LED Power-Up V.54 and V.52 Diagnostic Tests Remote Digital Loopback RDL Using the V.52 Bert Test Independently Shipping and Packaging TroubleshootingCalling Your Supplier Wire Gauge Capacitance Resistance Appendix Cable RecommendationsMULTI-FUNCTION LD Card Copyright 1995. Black Box Corporation. All rights reserved
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