Multi-Tech Systems MT2834BLR, MT2834BR manual Digital Loopback Test/V.54 Loop 2 Local/Manual

Page 58

Chapter 5 - Testing the Modem

ATU1 and hit ENTER to place the modem in Analog Loopback mode, in the Answer mode. Then repeat step 3.

5.When testing is completed, you may exit Answer mode by entering an Escape Sequence (+++AT<CR> or <BREAK>AT<CR>), which returns the modem to Command mode.

6.Your modem passes this test if the data entered from your keyboard are the same as the data received on your monitor. If different data is appearing on your monitor, your modem is probably causing the problem, although it could also be your computer. If your modem passes this test, but you are receiving errors while On-line, the remote modem or the phone line could be at fault.

5.2Digital Loopback Test/V.54 Loop 2 (Local/Manual)

The Digital Loopback Test is an on-line test that loops data sent from one modem across the phone line to another modem, then back to the first modem. See Figure 5-2.

There are two ways to put a modem into Digital Loopback mode.

1.Locally or Manually, described here in section 5.2.

2.Remotely or Automatically, see section 5.3.

Note: Loopback tests operate at all speeds except 300 bps. Disable error correction (&E0&W0<CR>) before engaging in loopback tests.

In this test the local modem is placed in Digital Loopback mode. Data is entered and transmitted from the remote modem (which is not in digital loopback mode), sent across the phone line to the local modem and looped back to the remote modem.

The test procedure is as follows:

1.Go into Terminal mode. Type AT and hit ENTER; you should get an OK message.

58

Image 58
Contents User Guide Revision Date Description Contents AT Commands and S-Register Summary Introduction Features IntroductionHow to Use This Manual Installation Serial Cable PreliminariesCard Cage Telephone LineInstallation PC Board Controls DIP-Switch Settings Switch Function Position EffectAnswer/Originate Originate call Async/Sync/Leased Line OOS Busy Out Toggle Switch Dip Switch Settings #13 Position EffectOut of Service/Test Jumper 2 MI/MIC Option JumperDial-Up and Leased Lines Modem LED Indicators On-Line Diagnostics Installation Serial Port Limitations How Can You Identify Your Uart Type? MSD Uart Identification, Screen Configuring Your Software Configuring Software for Your ModemPC Initialization Strings AT &F X4 S0=0 MMEW Modem Initialization Setup Changing Default Parameters Macintosh InitializationConfiguring Software for Your Computer MEW Configuration Parameters ScreenConfiguring Software for the Remote System Terminal EmulationWhen to Disable Data Compression File Transfer ProtocolsDisabling Error Correction AT &F S0=0 X4 &E14 MModem Commands Modem AT Commands Commands = 0, 1, 2 or DP0 #F2 Command Values Default = speed Q0 selects Result Codes displayed Reads value of S-Register r and displays value = 4 or Tone Callback Security Commands Command Break Atcr Values Default DescriptionCallback password with xxxxxx being callback password Remote Configuration Remote Configuration Procedures4 V.25bis Commands Password CommandsCSPs Registers Escape Code CharacterLine Feed Character S10 Carrier Loss Disconnect Delay Time S25 DTR Dropout Time Result Codes S36 Time Between DTR Inactive and Modem Off-HookTerse Verbose No Dial Tone Busy No Answer AT Commands and S-Register Summary Modem Testing Local Analog Loopback Test/V.54 Loop UuuuDigital Loopback Test/V.54 Loop 2 Local/Manual Digital Loopback Test local / manual Digital Loopback Test/V.54 Loop 2 Remote/Automatic Digital Loopback Test remote / automaticLocal Analog Loopback Test Synchronous Mode Local Analog Loopback Test Syncronous ModeDigital Loopback Test Local/Manual Synchronous Mode Digital Loopback Test Local / manual SyncronousDigital Loopback Test Remote/Automatic Synchronous Mode Digital Loopack Test remote / automatic SyncronousWarranty and Service Limited Warranty Tech Support ServiceRecording Modem Information Using FlashPro to Upgrade Modem Firmware Upgrading the MT2834BRSafety Warnings Internet Babt Requirements Compliance with Babt Requirements European Low Voltage Directive Compliance with BS6789 .1 and Part Compliance with BS6328 Part Appendices Appendix a Appendix a Canadian Limitations Notice Appendix B Technical Specifications Data Rates modemFlow Control 2400 & 1200 bps Frequency Stability Index Index Index Index MNP SCC XON/XOFF S000316