Multi-Tech Systems MT5600BA, MT5600BL Local Digital Loopback Test (V.54 Loop 2)

C Loopback Tests

93

3. Dial the remote modem and establish your online connection.

4. Type the escape sequence +++AT and press ENTERto bring your modem into

online command mode.

5. Type AT&T6 and press ENTER. The local modem responds to this command by

transmitting an unscrambled marking signal, which causes the remote modem

to place itself in digital loopback mode. Then the local modem exits online com-

mand mode and enters data mode.

6. Enter data from your keyboard. For this test, typing multiple uppercase U char-

acters is a good way to send an alternating test pattern of binary ones and zeroes.

Data received by the remote modem enters its analog receiver, is converted to

digital data, is reconverted into analog, and then is transmitted back to your

modem. Your modem passes this test if the data received on your monitor is the

same as the data entered from your keyboard.

7. To exit the test, type the escape sequence +++AT and press ENTER. This puts the

modem in online command mode. The modem should respond with an OK mes-

sage. If you wish to stay on line with the remote modem for normal data trans-

mission, type AT&T and press ENTER to exit the test, then type ATO and press

ENTER to return on line. If you wish to terminate the call, type ATH and press

ENTER to hang up.

Note: You can also start and stop a remote digital loopback test by using the front

panel LCD and buttons. See “Diagnostic Options Trunk” in Chapter 3.

Local Digital Loopback Test (V.54 Loop 2)

The local digital loopback test is identical to the remote digital loopback test with

one exception. Instead of using your modem to signal a remote modem to place it-

self in digital loopback mode, your modem is placed in digital loopback mode while

the remote modem is not. Data is entered and transmitted from the remote modem,

sent across the phone line to your modem, and looped back to the remote modem.

Computer or Terminal

UUUUUUUUUUU

UUU

Local MultiModem Remote MultiModem Computer or Terminal

Digital Analog DigitalAnalog

AT&T3

OK

Figure C-3. Local digital loopback test.

Test procedure

1. Open your communications software and go into terminal mode. Type AT and

press ENTER; you should get an OK message. Type AT\N and press ENTER to dis-

able error correction.

Contents

Main ii iii FCC Part 15 Industry Canada iv Chapter 1: Introduction Chapter 2: Quick Start Chapter 3: Using the Front Panel Contents v Chapter 4: AT Commands, S-Registers & Result Codes Chapter 5: Remote Configuration Chapter 6: Callback Security Chapter 7: Leased Line Operation Chapter 8: Solving Problems Appendix A: Regulatory Compliance Appendix B: Technical Specifications Appendix C: Loopback Tests Appendix D: Warranty, Service, and Technical Support Appendix E: Upgrading the Modem Page Page Page 2 Product Description Features General 1 Introduction 3 Data Fax What Is in Your Modem Package? Related Manuals Page What You Will Need We supply You supply Safety Warnings Step 1: Connect the Modem to Your System RS232 Connection Dialup Connection Two-Wire Leased Line Connection Four-Wire Leased Line Connection Phone Connection Power Connection Surge Protectors and Lightning Step 2: Install the Modem in Windows Adding the Modem to Windows Removing Your Old Modem from Windows Step 3: Install and Configure Your Software Step 4: Call the Multi-Tech BBS Trio DataComm Windows HyperTerminal Windows Terminal Step 5: Send a Fax Trio Fax Microsoft Fax Other Ways to Access Microsoft Fax References Page Page Modem Configuration LED Indicators Liquid Crystal Display (LCD) Option Selection Menu Structure Page Page Page Page Page Page Menu Options Status Basic Options Advanced Options Remote Configuration Options Diagnostic Options Phone Number Memory Options Caller ID Options Page Page AT Commands s Page Page Page Page Page Page Page Page =x Page Page Page Page Page Page S-Registers Page Page Page Result Codes Page Page Page Page Basic Procedure Setup Changing the Remote Configuration Password 5 Remote Configuration Changing the Remote Escape Character Page Page Setup Procedures Turning Callback Security On and Off AT Command Method 6 Callback Security Assigning Callback Passwords At Command Method Assigning Callback Phone Numbers At Command Method 6 Callback Security Calling Procedure Callback Security Commands Page Callback Assignments Page Page 70 Two-Wire Setup 7 Leased Line Operation Four-Wire Setup Dial Backup and Leased Line Restoral Dial Backup and Leased Line Restoral Setup 7 Leased Line Operation Page Page None of the Indicators Light The Modem Does Not Respond to Commands The Modem Dials But Cannot Connect The Modem Disconnects While Online The Modem Cannot Connect When Answering File Transfer Is Slower Than It Should Be Data Is Being Lost There Are Garbage Characters on the Monitor The Modem Doesnt Work with Caller ID Page Page Appendix A: Regulatory Compliance FCC Part 68 Telecom A Regulatory Compliance Fax Branding Statement Canadian Limitations Notice International Modem Restrictions Commission Decision CTR21 A Regulatory Compliance EMC, Safety, and Terminal Directive Compliance New Zealand Telecom Warning Notice Appendix B: Technical Specifications B Technical Specifications Page Appendix C: Loopback Tests Local Analog Loopback Test (V.54 Loop 3) Remote Digital Loopback Test (V.54 Loop 2) Local Digital Loopback Test (V.54 Loop 2) Back-to-Back Test Page Appendix D: Warranty, Service, and Technical Support Limited Warranty Service D Warranty, Service, and Technical Support Technical Support Online Warranty Registration The Multi-Tech BBS About the Internet D Warranty, Service, and Technical Support Ordering Modem Accessories Appendix E: Upgrading the Modem Upgrade Overview Step 1: Identify the Modem Firmware E Upgrading the Modem Step 2: Identify the Current Firmware Version Multi-Tech Web Site Multi-Tech BBS Step 3: Download the Upgrade File Multi-Tech Web Site Multi-Tech BBS Step 4: Extract the Upgrade Files Step 5: Set the Modem to the Factory Defaults Step 6: Upgrade the Modems Firmware Step 7: Restore Your Parameters Appendix F: Cable Pinouts RS-232 Pinouts Figure F-2. 9-pin to 25-pin RS-232 cable. DTE DB-25 connector DCE DB-25 connector Leased Line Pinouts Figure F-4. Two-wire leased line cable. Appendix G: ASCII Character Map Page A B C D Index E F G H T S U V W