3Com DIGITAL MODEM 3

3TROUBLESHOOTING

This chapter explains how to isolate and solve simple

problems encountered with the 3Com Impact digital

modem. Problems may stem from incorrect option settings

or improper installation. Follow the steps outlined in this

chapter.

There are no user-serviceable parts inside your 3Com Impact

digital modem. Unauthorized opening of the unit will void

the warranty.

Troubleshooting Tips

Before you call 3Com’s technical support organization for

assistance, check the following:

1The power supply is connected and the power LED is on.

2Turn the 3Com Impact digital modem power switch off

and then on again several times and observe the Test LED.

During power-up self-test, the Test LED ﬂashes.

■If the Test LED ﬂashes and remains on for more than a few

minutes, there is an internal failure. Notify your reseller that

the 3Com Impact digital modem has failed the self-test, and

order a replacement.

■If the LED goes off after the test has been completed, the

test has been successful.

3Verify that the ISDN cable is connected to the digital

modem, and make sure it is connected to the ISDN wall

jack.

Contents

Main 3Com Corporation 95052-8145 Santa Clara, California 5400 Bayfront Plaza C ONTENTS 3 A C B F IGURES T ABLES A How to Use This Guide Introduction UIDE Conventions Table 1 and Table 2 list text and icon conventions that are used throughout this guide: I NTRODUCTION Page 3Com Impact Digital Modem Features Data Capabilities Voice Capabilities Simultaneous Data and Voice Capabilities Analog Modem Capabilities 3Com Impact Digital Modem Package Contents Standard Package Contents Additional Contents ISDN Digital Line Conguration Requirements Computer System Requirements IBM PC or Compatible Requirements Apple Macintosh Requirements Cabling Requirements 2 C THE DIGITAL MODEM Page Installing the 3Com Impact Digital Modem Installing the Digital Modem in an IBM-compatible PC Page Page Conguring the 3Com Impact Digital Modem Conguration for IBM PC or Compatible Computer Page Page Page Page Page Conguration for Apple Macintosh Computer Page Placing and Receiving Calls Placing ISDN Data Calls Multilink PPP Calls With Dynamic Bandwidth Allocation Page Placing Analog Modem Calls Using Communications Software to Place Calls Receiving Data Calls Using the Phone Out Port Placing Calls Using the Phone Out Port Receiving Calls Using the Phone Out Port Protocol Support Async-Sync PPP Conversion QuickSelect 3 Troubleshooting Tips Page Page Page Downloading Firmware to Your External Digital Modem Page A O Page B REGISTERS, AND RESULT C AT Command Set for the 3Com Impact Digital Modem Table B-1 summarizes the AT command set. Page Page AT Command Set for Internal Analog Fax Modem Table B-1 summarizes the AT command set for the internal analog modem. Page Page Remote S Registers Page Page Digital Modem Result Codes Table B-4 lists the 3Com Impact digital modem result codes. C On-line Technical Services 3Com Bulletin Board Service World Wide Web Site Ask3Com on CompuServe 3ComFacts Automated Fax Service Support from Your Network Supplier Support from 3Com Returning Products for Repair