First set your speed, bits per character, and parity (async). The typically parameters set are; Autobaud (@An) to off, Command Echo to off, Quiet to On, DTR On, one unit to Answer mode (%O0) the other to Originate (%O1). After making your changes save them to memory (&W).

2. How do I configure the modem for Leased Line dial backup?

On both modems, set UADBU to on (%U1) and Lookback to on (%L1). Lookback instructs the modem to occasionally check to see if the Leased Line is back in service and able to handle data traffic. Use register S56 to define how often you want the modems to "lookback" to the leased line.

3. How do I setup the modem for pass-through security dialing?

On the Answering modem, first define your password (& name for additional security) by using the command AT&Zn. You can store up to 100 user password accounts in memory (&Zn). The command structure looks like this "AT&Zn:NAME:PASSWORD:PHONE:CONFIG:LINK:ATTR", however typically you will only use the Password, Name and Attr fields. Here's an example; "AT&Z5::Bk5L2cd::N". This places a user account in the 5th record with a password of "Bk5L2cd" and a "pass-through" attribute designator "N".

4. How do I setup for callback security dialing?

On the Answering modem, first define your password (& name for additional security) by using the command AT&Zn. You can store up to 100 user password accounts in memory (&Zn). The command structure looks like this "AT&Zn:NAME:PASSWORD:PHONE:CONFIG:LINK:ATTR", however typically you will only use the Password, Name and Attr fields. Here's an example; "AT&Z5::Bk5L2cd::N". This places a user account in the 5th record with a password of "Bk5L2cd" and a "pass-through" attribute designator "C".

5. How do I get my 28.8K/33.6K modem to work with a 14.4K modem? They try to sync up but never connect.

On the 2845 or 2853, set the register S40 to 0, then save the change and power cycle the modem. If you want to go back to connecting with faster speed modems set this register back to 5.

6. How can I tell what version firmware I have in my modem?

Type the command ATI3. This will return a value that will look something like 2845-AL 69-52860-310/311.

7. How can I upgrade the modem firmware?

There are 2 ways; one is by replacing 2-3 IC's, the other is by dialing into a Flash Upgrade server. Download the Modem Manager program "MMPlus.exe" and the file(s) associated to your modem type(s). Run the MMPlus program on a PC with a modem attached. From the modem you wish to upgrade dial to the MM server with the command ATDT555-1234F (but use the real phone number.

8. I can't "talk" to the modem. Why?

Several conditions can cause this. First check the condition of the DSR light. If it is either On steady or blinking you need to press the DISC button (on a rack mount unit) or the DL/DIS button on a tabletop unit. Now try again. If you still can't talk to the modem Command Echo may be turned off (ATE0) so try a simple command like ATI3. If you still can't get the modem to talk you may either be using the wrong Com Port, have a mis-matched speed, or a bad cable.

9. What do I do when the modem fails its self-test (as indicated by 4 low pitch beeps)?

The first thing to do is watch to see what LED lites after the modem fails its self-test (as indicated by 4 low pitch beeps)? The first thing to do is watch to see what LED lites after the 4 beeps, this will tell you which self-test failed. The majority of self-test failures are caused by corrupted non-volatile memory. The modem will still operate, but you may find a slight abnormal behavior. To correct this type of problem you can do a "Master" reset. This will clear the NVRAM and place the unit back into its original factory mode. Prior to resetting the modem it is best to document all of the configuration changes as well as any passwords or user accounts in the phone directory. After you have this done, just enter the command "AT&W255". Your modem is now reset and should be able to power cycle the unit and hear the normal 3-incrementing tones. If the unit still fails check again the LED that comes on right after the 4 beeps and contact the factory for corrective action.