Hardware Flow Control &E4, Modem Terminal | Black Box MD1641A

SERIES II INTELLIGENT DATA/FAX MODEMS

Modem-Initiated Flow Control

RS/232/V.24 Computer or

	Modem		Terminal
		data flow


	Computer-Initiated Flow Control

RS/232/V.24

Modem

data flow

Computer,

Terminal, or

Printer

Figure 5-2. Flow Control and Pacing

Hardware Flow Control &E4

With Hardware Flow Control, the modem uses its RS232C interface to control the flow of data from the computer or terminal to which it is attached. The CTS (Clear to Send) signal on Pin 5 of the RS232C interface is brought low to stop the flow of data, and is brought high to restart it. When you select Hardware Flow Control as your Modem Initiated Flow Control method, you will also be selecting it for Pacing.

The difference between the two, however, is that Modem-Initiated Flow Control uses the Pin 5 CTS output signal, while Pacing uses the Pin 4 RTS input signal.

Modem commands are used to select the method of flow control used by the Series II Modem when its error correction capabilities are used. These commands are covered in Section 5.4.9. If neither method is selected, the modem defaults to no flow control (&E3).

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Black Box MD1641A, MD1640A manual Hardware Flow Control &E4, Modem Terminal

Contents

Series II Modem Series II Modem 336+ Series II Modems Series II Intelligent DATA/FAX Modems Contents Manual Dial and Automatic Answer Command Mode Registers Callback Security and Remote ConfigurationModem Testing Other Appendixes DIP-Switch SettingsAppendix a Troubleshooting Introduction and Description Introduction How To Use This Manual Software Configuration Installation and ConnectionAT Command Mode Operation Manual Dial and Automatic Answer DIP-Switches Callback and Remote ConfigurationTesting Your Modem Modem Features What is in Your Modem Package? Fax Features Technical Specifications Intelligent Features Mode of OperationCommand Buffer Modulation Frequencies Fax CarrierLease Line Restoral Carrier Frequencies Diagnostics ConnectorsIndicators Operating Temperature Modem LED Indicators Power Introduction and Description Controls on PC Board Safety Warnings Installation and Connection Installation Series II Modem 336 MD1641A Connections Series II Intelligent DATA/FAX Modems Is Your Series II Modem Ready for Use? Operating Your Series II Modem Simple Operations Answer/Originate Voice/Data Toggle Switch Serial Port Limitations Introduction How Can You Identify Your Uart Type? Software Configuration COMnFIFO=1 16550 Uart and Windows Configuring Software for Your Modem Configuring Your Software PC Initialization Strings Changing Default ParametersAT &F X4 S0=0 M AT &F X4 S0= 2 M Macintosh Initialization Other ParametersAT &F X4 M AT &F X4 &E5 &E13 &D0 M Configuring Software for the Remote System Configuring Software for Your ComputerSoftware Configuration AT &F9 &W0 CR Terminal Emulation When to Disable Data CompressionFile Transfer Protocols User Guide for Series II Modems AT &F S0=0 X4 &E0 M Disabling Error CorrectionAT &F S0=0 X4 &E14 M Dialing/On-Line/Answering Manual Dial and Automatic Answer Series II Intelligent DATA/FAX Modems Automatic Leased Line Restoral Operation 336+ Only Manual Dial Backup Call Termination 336+ OnlyDial Backup and Leased Line Restoral 336+ Only Series II Intelligent DATA/FAX Modems Manual Call Origination Dial-Up Operation 336+ Only Automatic Answering Handshaking Details Manual Answering Call Termination Abort Timer AT Command Editing Command Mode Functional Modes Command Mode Functional Modes Summary of AT Commands Memorize Phone Numbers #L1 #L0#L2 #L3 E15 E14$BA1 +++ATCR Sr? Result CodesSr= #RCBNxx Q1 Standard AT Result Codes Q0 Series II Result Codes Continuous Redial a or Dialing Commands Dialing Action CommandsDial Command D DTR Dialing $D Dialing a Stored Number N Pulse or Tone Dial P or T Dial Modifier CommandsVoice/Data Dialing $VD Long Space Disconnect Y Set Pulse Dial Ratios &PAutomatic Pauses in Dialing Wait for New Dial-Tone W Return to Command Mode after Dial Command ExecutionReverse the Mode of Operation R Calling Card Detect Tones $ Flash On HookQuiet Answer @ ATDT101099907247465500$0123 4567 8910 Storing Phone Numbers D...N Phone Number Memory CommandsNumber Linking NN ATX4&E1&E5&E13&E15DT17247465500N3 Listing Numbers Stored in Memory L Loading Factory Defaults &F Configuration and Default Storage Commands Unix Uucp Spoofing $SP Modem Reset Z32terbo Enable/Disable #V 336 Only Synchronous Transmit Clock Select &X Async/Sync Mode Switching &M Echo Command Mode Characters E Command Response Result Code CommandsResult Codes Enable/Disable and No Response Answer Q Chap 5 Command Modeter Result Codes Basic and Extended and Call Progress Selection Result Codes Verbose/Terse Command Mode Enable/Disable Trelis Coded Modulation #T Phone Line Conditioning CommandsGuard Tones &G Phone Line Monitoring Speaker M Cleardown at Disconnect &CD Fallback Modes When On-Line #FEnable/Disable Lowspeed Fast Connect $FC 336+ Only Carrier Detect Control &C 7 RS232C Interface Control CommandsAuto Speed Detect #A Clear to Send Control &R Data Terminal Ready Control &D Data Set Ready Control &S Error Correction CommandsCTS/RTS Interaction Control &RF DSR/CD Interaction Control &SF Auto-Reliable Mode &E1 Normal Mode &E0 Mode Select #L Reliable Mode &E2Originate Mode Answer Mode Auto-Reliable Buffering $A Enable/Disable Auto Reliable Fallback Character $F Retransmit Count $R Error Correction/300bps $E Flow Control Commands Modem Terminal Hardware Flow Control &E4 Xon/Xoff Pass-Through &E7 Xon/Xoff Flow Control &E5 Hewlett-Packard ENQ/ACK Pacing &E9 Normal Mode Modem Flow Control On &E11Send Xon/Xoff Characters #X Maximum Block Size &BS Terminal/Computer Initiated Pacing &E13 Parity Selection #P Asynchronous Word Length Selection $EB 336 Only #X1 = #X0 = Normal Mode Modem Flow Control Commands Speed Conversion CommandsEnq/Ack Pacing Commands Modem Baud Rate $MB Speed Conversion $BA Serial Port Baud Rate $SB Help Screens $H Immediate Action Commands Windows 95 Autodetect Inquiry Inquiry for Product Code Listing S-Register Values L6 Listing On-Line Diagnostics L8Listing Current Operating Parameters L5 L7 On-line diagnostics information On or Off Hook H Break Atcr Exiting Command Mode, Going Back On-Line O Line Probe CommandsForce Answer Mode a Immediate Action Line Probe Commands Format of Line Probe Graph or Table Commands DF0DP1 DF1 Rings Which Have Occurred Number of Rings Until Modem Answers Line Feed Character Escape Code CharacterReturn Character Backspace Character Time for Carrier Abort TimerWait Time for Dial Tone Pause Time for Comma Carrier Detect Response Time S10 Carrier Loss Disconnect Delay Time S11 Tone Dialing Tone Spacing and Duration S13 Remote Configuration Escape CharacterS15 Callback Time Delay S18 Automatic Leased Line Restoral 336+ Only S16 Callback AttemptsS17 Changing Break Time S25 DTR Dropout Time S19 Dial-Back Timer 336+ OnlyS24 PBX/CBX Disconnect Drop Time for DSR/CTS/CD S29 Local Inactivity Timer S26 Failed Password Attempts S32 Time Elapse for Escape Sequence S30 Inactivity Timer S48 Program V.34bis Connect Speeds S36 Time Between DTR Inactive and Modem Off-HookS37 Time Between DTR Active and Modem On-Hook Examples of Assigning Values Reading and Assigning S-Register Values ATS0=30S3?, and ATS7=55S7? AT Command and S-Register SummaryExamples of Reading Values Callback Feature Description Callback Security Remote Configuration Remote Configuration Description Callback Security and Remote Configuration To change your Remote Configuration feature status Error To set parity of the password/message prompt To turn your modems Callback Security feature on and off AT#DB2CRÊorÊAT#DB1CR AT#IxxxxxxxxxxCR xxxxxxxxxx from TableAT#CBN0xxxxxxxxxxCR AT#CBN1xxxxxxxxxxCR AT#SyyyyyyyyyyCR yyyyyyyyyy from Table Password Callback Operational Sequence Procedures Remote Configuration Operation Procedures StepProcedure Remote Configuration Procedures Callback Security Enable/Disable #DB Remote Configuration and Callback Security AT CommandsAssign Passwords for Callback Phone Numbers #CBN Change Setup Password #S Change Login Password #IErase Callback Password #RCBNxx Erase Callback Phone Number #RDNxx Remote Configuration Character S13 Remote Configuration/Callback Security S-RegistersCallback Time Delay S15 Callback Attempts S16 Local Inactivity Timer S29 Failed Password Attempts S26 Modem Testing Local Analog Loopback Test/V.54 Loop Modem Testing Digital Loopback Test local/manual Digital Loopback Test/V.54 Loop 2 Local/Manual 119 Digital Loopback Test remote/automatic Digital Loopback Test/V.54 Loop 2 Remote/Automatic Back-to-Back Test 122 Local Analog Loopback Test Synchronous Mode Synchronous Mode Testing Digital Loopback Test Local/Manual Synchronous Mode Digital Loopback Test Remote/Automatic Synchronous Mode 126 DIP-Switch Settings Series II Modem 336+ MD1640A PC Board DIP-Switch Option Settings 129 130 Switch #4 AS/400 Mode Synchronous Mode/Leased Line/Dial-Up 131 132 133 134 135 Speaker Volume Control Function Position Effect Recording Option Configurations AT vs. Series II Result Codes DIP Switches #13-16 None of the LEDs Light When the Modem Is On Possible Causes and Solutions Modem Does Not Respond to Commands 141 Modem Dials But Cannot Make a Connection 143 Modem Disconnects While On-line Modem Cannot Connect When Answering Am Losing Data File Transfer Is Slower Than It Should Be Am Getting Garbage Characters on the Monitor Modem Model No Contacting Black Box Recording Modem Information Shipping and Packaging Making the Call Upgrading the Series II Modem’s Firmware Tone Dial Frequencies 697 770 852 941 1209 Digits 1336 1633 Appendix B Dial Pulse and Tone-Dial FrequenciesDial Pulses Command Appendix C Command SummaryDescription $An $BAn BSnCDn DsNd $Dn DFnDPn $EBn $En#Fn $FCn $Hn Command Values Description NdNe #Ln$MBn RFn #Pn$Rn $SBn Sr=nSFn $SPn $VDn #Tn #Xn 160 Command Description #DBn Callback Security/Remote Configuration Command Summary#CBNyyxxxxxx + Dxxxxxx???Nxx Password Command Summary 25bis Commands DIP-Switch Condition Effect Appendix D DIP-Switch SummaryAsynchronous Mode Synchronous Mode 166 Appendix E S-Register Summary Appendix E S-Register Summary S15 S13 S24 S36 Digit Words Appendix F Result Code SummaryEffect 172 Appendix F Result Code Summary Appendix G V.25bis Operation Delayed and Forbidden Numbers 25bis Operation Appendix G V.25bis Operation 25bis Set-Up and Initialization 25bis DIP-Switches 25bis Mode AT Commands 25bis Responses Result Codes 25bis AT Commands Change Serial Baud Rate CSP Command Enable/Disable V.25bis Mode $V Command Dial Phone Number Provided CRN Command Disregard or Connect to Incoming Calls DIC or CIC Command Listing Delayed Phone Numbers RLD CommandListing Forbidden Phone Number RLF Command DTR Dialing $D Command Italy ITU V.25bis Country Specific Information Austria Belgium France Singapore Appendix H Series II Modem Cables Appendix H Series II modem cables 188 Appendix I RS232C Interface Specifications Appendix I RS232C Interface Specifications Request To Send Pin 4, RTS CA Received Data Pin 3, RD BBDirection to modem Direction from modem Clear To Send Pin 5, CTS CB Signal Ground Pin 7, SG ABData Set Ready Pin 6, DSR CC Data Carrier Detect Pin 8, CD CF Data Terminal Ready Pin 20, TR or DTR CD Transmit Clock Pin 15, TC DBReceive Clock Pin 17, RC DD External Transmit Clock Pin 24, XTC Ring Indicator Pin 22, RI CETerminal Busy Out of Service Pin 25, OOS FCC and IC EMI/RFI Statements Appendix J Regulatory Information FCC Part 68 Regulations for Telephone-Line Interconnection Appendix J Regulatory Information 196 197 Canadian Limitations Notice Copyright 2000. Black Box Corporation. All rights reserved