Nortel Networks RTU-292 operation manual VOX Sensitivity Measurement

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RTU-292 Operations Manual

6.5.3 VOX SENSITIVITY MEASUREMENT

The following test procedure measure the sensitivity of the VOX in the RTU-292. This is the amplitude of the incoming signal from the telephone line required to trigger the VOX.

Figure 6-2 VOX Sensitivity Test Set-Up

6.5.3.1 VOX Test Procedure

1.Disconnect the RTU-292 from all other equipment and connect the test equipment as shown on Figure 6.2.

2.The PSTN level setting must be known. To determine this, remove the top cover and note the positions of SW2-1, -2, and -3.

3.Start with the following pushbuttons OFF: TEL LINE/PHONE and TEL LINE/RADIO. Push the TEL VOX button ON. The positions of the other buttons are unimportant.

4.Set the audio signal generator frequency to 1 kHz with an output amplitude of less than - 40dBm (7.7mV rms).

5.Push the TEL LINE/RADIO button to start the adaptation cycle.

6.When the initial adaptation cycle is complete, slowly increase the audio generator amplitude until the Keyed LED on the RTU-292 comes on. The audio generator amplitude at this point (read directly by the audio voltmeter) is the VOX sensitivity. The VOX trip point is dependent on the setting of the PSTN levels and the VOX sensitivity setting. It should be 16 + 2 dB below the PSTN setting as listed in the table below:

VOX Sensitivity	VOX Trip Point
MAX	19 + 2 dB below the PSTN setting
MED	16 + 2 dB below the PSTN setting
LOW	13 + 2 dB below the PSTN setting
MIN	10 + 2 dB below the PSTN setting
	6-23	JPS Communications, Inc.

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Contents JPS P/N Revision July JPS Communications, IncPhone 919 Fax 919 Proprietary StatementTable of Contents RTU-292 Theory of Operation Front Panel Buttons and Indicators Schematic Diagrams List Of Figures List of Tables Glossary This page intentionally left blank General Scope DescriptionTelephone Interface AssembliesMain Board Handset/Speaker Interface Power Supply SectionRadio Interface DSP ModuleQty Part Number Equipment and Accessories SuppliedOptional Equipment Not Supplied OptionsRTU-292 Specifications Reshipment of Equipment GeneralUnpacking and Inspection FCC Part 68 Regulations Installation OverviewInstallation Considerations Feature / Function Adjustment Default Setting 1RTU-292 Factory Default SettingsInput Power Selection Power RequirementsDC Input Power Selection Line Voltage SelectionSetting Telephone Send and Receive Levels Configuring the RTU-292Programming Mode Setup Parameters Factory default settings are indicated by an asterisk Recommended Phone Line SettingsType of System Telephone Send/Receive LevelsVOX Hangtime VOX HangtimeVOX Sensitivity VOX SensitivityDial Mode Dial ModeTelephone Ring Volume RX Line Input ImpedanceSW1-3 Radio Control Off Disabled Enabled Radio Control ModeFull/Half Duplex SW2-8 Full/Half Duplex Off Full Duplex10Password Protection Password Protection11Voice Prompts Enable Voice Prompts14TX Level Set-up Mode 12Local Phone EnableInterconnect Information 13 Local Phone Ringthrough15J1 TEL Line RJ-11C Telephone ConnectionPin Function Radio Connection17J7 Handset RJ12C Jack Handset Connector16P1-RADIO DB-9 Male 18Terminal Block 6 Position Terminal Block19P2 RS-232 Connector DB-9 Male Audio Level Setup and AdjustmentsSetting the Transmit Level 5 RS-232 Connection10.1.2 Setting the Receive LevelRTU-292 Operations Manual Outline Dimensions Control and Connector Locations Location Of Internal Option Settings Internal Option Setting Details Audio Interface Wiring Diagram Interface Details Installation Checklist Installation ChecklistOptions Installation and Configuration Front Panel CONTROLS, Indicators and Connectors Phones Volume Control Speaker Volume ControlKeypad TEL Line ButtonsAuto ANS Button Speaker ButtonsAudible Ring Button KEY Pushbutton1 P1 Radio Connector Rear Panel Connectors4 J2 Local Phone Connector 7 P1 AC Power ConnectorOperation Overview OperationUSE of the RTU-292 Speaker to Monitor Audio Placing a Telephone CallConnecting the Radio to the Telephone Line Using the Handset with the RadioReceiving a Telephone Call Putting a Telephone Call on Hold8.2 Manual Phone Patch Procedure8.1 8.4 8.38.5 8.6Remote KEY Negative Acknowledge ErrorSelf Test Automated OperationWaiting For Input Query Disconnecting DisconnectRadio Is Keyed Keyed Radio Is Unkeyed UnkeyedRTU-292 Adapts To The Phone Line Caller Enters The Password if enabledCaller Dials The RTU-292 Terminating a Call RTU-292 Enters the Command ModePlacing a Call in the Command Mode Operating the RTU-292 from the Front Panel Keypad Dtmf Control CommandsDtmf Command Function 1Standard Dtmf Operational Commands2Programming Mode Dtmf Commands Calling Timer RTU-292 Password ProtectionInactivity Disconnect Timer Programming the Speed Dial Directory Using the RTU-292 Speed Dial FeatureUsing the Speed Dial Feature Optional 4 Wire Operation Factory ResetSpeed Dial Reset Audio BUS Arrangement Front Panel Buttons and IndicatorsMain Board Telephone Receive Circuits Telephone Interface CircuitsTelephone Send Circuits Radio Interface Circuits Ring Detector and Tone RingerReceiver Input Amplifier Transmitter Audio OutputFSK Modem Dtmf DetectorMicrophone Circuit Speaker and Headphone CircuitsAdaptive Hybrid Audio DelayNoise Generator Peak DetectorAC Power Supply Power SupplyDC Power Supply 8 CPUVoice Prompt Option Option Interface BoardPrompt Tone Generator Speech ProcessorVoice Prompt Software Local Phone OptionInterface Circuitry DIAL/BUSY GeneratorsCommands Sent to the RTU-292 RS-232 Remote Control Overview1Command Summary Audible Ring Command Null CommandAuto Answer Command Dial Command Date CommandDtmf Command Disconnect CommandHandset Radio Command Handset Phone CommandSpeaker Radio Command Speaker Phone CommandSD nnALL num.? CR Speed Dial CommandTel-Line Radio Command Tel-Line Phone CommandSoftware Version Command Time CommandResponse Summary Status Returned from the RTU-292Call Starting Response Null ResponseAuto Answer Response Dtmf Response Dial ResponseDisconnect Response Handset Radio Response Elapsed Time ResponseHandset Phone Response Speaker Radio Response Speaker Phone ResponseTel-Line Radio Response Speed Dial ResponseTel-Line Phone Response Version Response Time/Date ResponseResponse Error Codes Response Error CodesCall Progress Responses from the RTU-292 Call Progress ResponsesRepair or Replacement Preventive MaintenancePerformance Testing AlignmentHybrid Balance Measurement Hybrid Balance Test Set-Up Main Hybrid Test Procedure Alternate Hybrid Test Procedure VOX Sensitivity Measurement VOX Sensitivity Test Set-Up VOX Test ProcedureFault Analysis Description Replaceable Parts ListDescription Reference Designator RTU-292 Operations Manual Reference Designator RTU-292 Options Special Software VersionsVoice Prompts Enable Installation and ConfigurationSW1-6 Voice Prompts Off Disabled Enabled OperationVoice Prompt Option Installation Local Phone Enable Local Phone Option Installation and ConfigurationSW1-7 Local Phone Off Disabled Enabled SW1-8 Ringthrough Off Disabled EnabledLocal Phone Option Operation 5Local Phone Dtmf CommandsVMM-100 Analog Interface VMM-100 HardwareVMM-100 DSP Section VMM-100 Software VMM-100 Installation and ConfigurationVMR Algorithm Noise Reduction AlgorithmVMM-100 Option Installation Environmental VMM-100 SpecificationsVMM-100 Switch Functions VMM-100 I/O Connector Information P9Dtmf Access Option After the Call Begins RTU-292 Prompts for Confirmation Squelch Break Access OptionSetting The Date Setting The TimeCall Logging Option Checking The Time And DateControlling the Radio VIA the RTU-292 Front Panel Keypad Radio Control OptionCommand Followed By Command Description 9DTMF Radio Control CommandsSchematic Diagrams Blank Index Environmental Self Test Speech Processor