Near Loopback for codec testing | Telos ZephyrExpress manual

Near Loopback for codec testing

When the Codec: Loopback menu item is set to Near, incoming audio gets coded in the usual manner, sent into the ISDN interface but then looped directly back to the decoder. This checks over 90% of ZephyrExpress’ functionality with no ISDN line present.

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IMPORTANT NOTE!

If you are using the European ISDN TA and arenÕt connected to an active ISDN line, you will hear dropouts in the audio signal during Near Loopback. This is not a problem with the equipment.

COMPATIBILITY NOTE!

Near Loopback requires both the transmit and receive coding methods to be compatible.

CURIOSITY NOTE!

Near Loopback is great for trying ZephyrExpressÕ audio coding algorithms with- out an ISDN line, and getting used to what the different settings sound like. ItÕs also great for impressing people with the quality that ISDN can yield over a good system.

9-8 TROUBLESHOOTING

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Telos ZephyrExpress user manual Near Loopback for codec testing

Contents

UserÕs Manual Manual Version 1.0 / April What youÕve got here Customer Service Feedback Blank Screen? Test LinesZephyrExpress will dial a test line for you Warranty UpdatesPower Supply Trademarks Repairs Table of Contents Isdn Reference TroubleshootingSchematics and Data Sheets Appendix System Functions Introduction H i c t Block Diagram Menu Structure Utility Menu Quick Results Tune into one of our test lines Part Quick Results Gather information about your Isdn line Isdn type, check one Isdn telephone numbers with area codeMSN numbers, i f supplied Euro ETS300 only Set up the hardware Quick Results HConfigure ZephyrExpress for your Isdn line Quick Results Call yourself testing your unit and the line Configure the Codec HOT TIP Set up an audio input and output Place the call to yourself Quick Results Tune into one of our test lines Isdn TIP What do I do if IÕm totally lost? Fast Answers to Frequently-Asked QuestionsHe Basics Knob either direction to change the LCD Contrast How do I use the menus? Scrollbar Highlighted How do I enter numbers or names? How do I use a menu that appears locked?How do I lock a specific menu? Right H6 How do I create my own Setups and Master Setups? HOT TIP How do I manually enter a network setup? How do I test that IÕve set things up properly? Alternate test procedure What do I do if I canÕt connect? Audio setup How do I set ZephyrExpress for my microphones? How do I use line-level sources? How do I test my audio and compression setups? How do I create a monitor mix? Isdn Connection How do I place a call? What do I do if they canÕt hear me? HHOT TIP How do I send a test tone? How do I hang up? Where do I find answers to other questions? Circuit information · 1-4 coding methods · Quick Results Zephyrexpress Hardware About our hardware Front Panel Mixer Section Send Mixer Monitor Mixers Level Controls Display section Send and Receive MetersLock LEDs LCD Display Control section Edit knob Dial button Drop button Rear Panel Mode switches Data connection sectionIsdn Connections Interface Pinouts Remote Control jacks Line C Top pin Inputs RS-232 PinoutsParallel Port Output 12 N/C Input 15 N/C About the XLR Connectors Audio i/o sectionOutputs ZephyrExpress All XLR PinoutsMicrophone Inputs Ground Audio + Monitor 1 XLR outputs Line InputsConductor Input plug Direct Isdn Receive outputs Monitor 1, Monitor 2 Headphone outputs Power connectionPower Supply Jack Headphone Jacks Power Input Power Supply XLR Output+5Vdc @ 5A +12Vdc @ 1.5A 12Vdc @ .5A System Ground Zephyrexpress Hardware Zephyrexpress Hardware Audio Operations Console at your fingertips Mix flexibility Send Mixer Routing Beware the Phantom Mic Routing Switches Compression, will make any perceptual coder less efficient Routing, convert the mic inputs to line-level Line Routing SwitchGain Bold Face Front Panel Hardware Send Level Controls Send Meters Receive Meters Monitor Routing SwitchesMonitor Mixers Send About Monitor Panning Adjusting individual monitor panning Monitor 1 Send Receive Meters Lock lights Receiving calls Analog call signal routingAnalog G.711 phone calls Talkback and cues can cut the cost of remote broadcasts Placing calls Hanging up Dealing with Delay Mix-MinusPhones and Remotes Remote Site Audio Operations Layer 3 Features Compatibility Overview Introduction to Audio Coding Basic Principles of Perceptual Coding Coding Layer 3 Features Psychoacoustic Masking Ancillary Data Redundancy ReductionBit Reservoir Buffering Bands Layer 3 Joint Stereo 722 Layer 2 Joint StereoLayer 2 Mono-128 Cascading Mixed Mpeg Layer 2 And Layer 3 Signal Chains Audio Freq. Response/stereo Audio Coding Comparison ChartAlgorithm Audio Freq. Response/mono Layer 722 With one transmission path Delay vs. QualityDual vs Stereo vs Joint Stereo in Layer With two transmission paths With one transmission path Dual Site OperationLayer 2 Mono64kpbs vs MONO128 Dual vs Jstereo With two transmission paths Sampling Rate Compatibility Between Telos CodecsWith Non-Telos Equipment Coding Coding Autodial Setups Codec menu Audio menu Isdn menu System menu Safe mode menuMenu Overview Menu System Typical menu Navigation Shortcuts Getting Help Weõre not Fortune Tellers Menu Overview Utility Menu Using Setups Applying a SetupCreating or Changing a Setup Master Setups Applying a Master Setup Creating or Changing a Master Setup Auto-creating a new Master Setup Manually creating a Master Setup Updating an existing Master SetupDeleting a Master Setup Autodial Setups Creating a new AutodialEditing or deleting an Autodial Menu Details Codec menu Isdn TIP Audio menu See , Audio 75 dB @ 100 Hz -10 dB @ 40 Hz Isdn menu Directory Number 7 digits System menu Seconds Minute Minutes Minutes Never Safe mode menu Menus Ordering Central Office Switches and Protocols Background Basic Rate Interface BRIZephyrExpress Isdn Compatibility Isdn Basics Background Basic Rate Interface BRI Isdn TIP Spids Get the SPIDs Get the SPIDs Directory Numbers DNs Long-Distance Digital Connectivity Switch carriers Dealing with The Phone Company Details, Details CSD and CSV NT1s ZephyrExpress Isdn CompatibilityProtocols Terminals and Terminal Types Ordering Central Office Switches and Protocols1 National ISDN-1 USA and Canada Zephyrexpress Settings for YOU to Enter AT&T Point-to-Point Custom USA, Japan, Israel, some others Zephyr Settings for YOU to Enter AT&T Point-to-Multipoint Custom Euro-ISDN Europe, Hong Kong, some others Isdn System Functions Software Updates Introduction ZephyrExpress data ports Serial Port Communicating Pin GroundPin Security Levels Hello, ZephyrExpress Command Help Login user ¶ Command Language Details Compatibility Note Display current encoder input & decoder Kept Times # for decimal numbers Parallel Port Ground, the call is dropped System Functions Troubleshooting First Steps Thinking About Problem Solving General Troubleshooting Look into the Lights Diagnostic AidsOther Ideas Front-panel LEDs Loopback modes TheyÕre disconnected during Far Loopback modeFar Loopback for local audio testing NT1 status LED Block diagram of the audio circuitry during Far Loopback Near Loopback for codec testing Operation Far Loopback from the distant studioLoopback Summary Some Error Conditions No functionality the box is totally or partly dead Condition Isdn Connecting OK, But No Audio Site B, but works perfectly when site B calls site a Condition No Audio In Both Directions Condition Audio In One Direction OnlyCondition Audio Distorted Condition Major Echo Action Isdn ProblemsError Messages Condition CanÕt Get Isdn Ready Ready Indication Ready when the switch type is set to PTP, and you cannot Dial, itÕs likely that your line is really National ISDN-11 Really Important Isdn TIP Can you place a pots call? What does the Isdn Cause phrase say? Intermittent Isdn Problems Isdn Cause Phrases/Values Cause No No route to network Cause No No route to destination. Prefix 1 dialed in errorCause No Check number, redial Cause No No prefix Cause No Call rejected Cause No No far end responseCause No No answer Cause No Number changed Cause No No circuit available Cause No Net problem, redialCause No Access information discarded Cause No Net out of order Cause No Requested facility not subscribed Cause No Service operation violatedCause No Resource unavailable Cause No Incompatible bearcap Cause No Protocol Error, Unspecified Cause No Invalid information element contentsCause No Timeout disconnect Cause No Message type nonexistent or not implemented Troubleshooting Schematics Appendix ÒNominalÓ Levels Level, Gain, dBu and dBm Codec Compatibility Information CCS Comrex Intraplex YouCom Comprehensive ZephyrExpress Compatibility ListDialog CCS CDQ1000 CCS Prima CCS CDQ2000CCS CDQ2001 Comrex Layer-II DX-200 Philips MPR LIIBlue PKI G.722 phonePKI Magic Philips MPR Baby Blue Digifon List Telos World Wide Web site AudiobahnWWW Paper WWW Phone EdNet List of Known Working SPIDs by Telephone Company Pacific Bell Northern Pittsburgh Tele- phoneNynex Southwestern Bell Ordering Isdn Company Telephone Number Worldwide WEB IOC Capability Packages Protocols SPIDs CSD and CSV56/64kbps NT1s Terminals and Terminal TypesLong Distance Carriers Faxable Isdn Order Form for use in US only Faxable Isdn BRI Line Order Form Page 1 From Location for line Protocol National ISDN-1 Protocol AT&T Point-to-Point CustomCO Values Give us Protocol AT&T Point-to-Multipoint CustomProtocol Northern Telecom DMS100 ÔFunctionalÕ Custom, PVC1 Not supported by ZephyrExpress Appendix