Modem Reset

Keeping your connection statistics (Updated 8-Aug-01)

If you get blank or zero data from modem diagnostic commands after an Internet (DUNS) connection, your modem is being reset.

There are several things that can reset the modem:

Another software program (like Fax, voice-messaging, etc.)

The terminal program you are using to look at the data (like HyperTerminal)

The commands DUNS (dial-up-networking) gives to your modem at the end of a session.

Not all modems behave the same in how they retain diagnostic data, or what command(s) clear them. Even though the latest Microsoft specification indicates that any of the following commands will reset Universal Diagnostic (AT+UD) data: ATZ, AT&F, ATD, ATA, many modems will retain some or all the diagnostic data with the AT&F command.

Note - Modems using the Lucent LT chipset (Apollo/Mars) starting with firmware version 5.32 write diagnostic data to the Windows registry, so last call information will survive even a power-off!

If you have another software program that uses the modem while your not on the net, disable it, or set it to a manual/off mode, or send only.

If you use HyperTerminal, make sure you have it set up to access the COM port the modem uses, not the modem name with a connection to dial. (See Setting up HyperTerminal.)

The last is the trickiest. The .inf file for your modem includes commands that are sent by DUNS (dial-up-networking) after your modem hangs up. If this command resets the diagnostic data, you have to eliminate that reset. For example, the .inf file supplied for x2 USR Courier modems in '97 included the ATZ command - which resets the modem and the diagnostic data. (This was changed with the V.90 .inf file - AT&F1 is sent, along with other commands: this resets the modem to factory defaults, but does not clear the diagnostic data.) More recently, it appears that a number of .inf files for Rockwell and Lucent modems have appeared that clears the diagnostic data. The procedure to modify the .inf file for the '97 x2 Courier .inf file is included below; the same process can be used to modify .inf files for other modems - as long as you know what command is clearing the diagnostic data. This normally will be either AT&F and/or ATZ. You can determine if these commands reset the data by using HyperTerminal, dialing a number, disconnecting, examine the data, then issue the AT&F/ATZ and see which clears the diagnostic data. If both commands reset diagnostic data, you could use simply AT as the reset command.

I have tested and used the following procedure with the .inf file for the Courier v.Everything modem (pre-V.90 release) mdmusrcr.inf:

(1) Copy the mdmuscr.inf file from your Windows .inf folder to a new or existing folder (like C:/USR) (Use Find if you have trouble locating the file [Right-click the Start button, then left-click Find; make sure you 'look in' All Hard Drives or the root of your system drive - usually C:\] The make another copy of the file in the new folder, renaming the file mdmusrcr.org

(2) Edit the mdmusrcr.inf file (use Notepad) - search for ATZ; change it to simply AT

(3) Save the edited file (mdmusrcr.inf)

(4) Uninstall (remove) the modem from Control Panel->Modems

(5) add the modem from Control Panel->Modems (do *not* use auto-detect; select from list, select Have Disk, and enter the directory where the edited file resides) Note: if you have plug and play, you may need to re-boot before completing this step; otherwise Windows may not install the modem on the correct COM port, or 'really' remove the old modem. If this is the case, when Windows reboots, it will install the modem: make sure to use the Have Disk... option to specify the modified .inf file.

(6) To make sure your modem defaults to the appropriate settings, from a terminal program give the modem AT&F1 (and any other non-factory settings you wish to use) then AT&W.

If you have a Courier v.Everything with V.90 firmware:

The new .inf file for the V.90 does not give the modem a reset command (ATZ); it uses AT&F1 which resets the modem to factory defaults, but does not clear the last connection data. If you want your modem to use non-standard factory settings, you must use a similar procedure to change the .inf file:

(1) Copy the mdmusrv90.inf file to mdmusrv90.org (make a backup copy of the original)

(2) Edit the mdmusrv90.inf file - search for AT&F1 (it appears 3 times) - delete the &F1 (note - the first instance is simply AT&F1 which I change to AT; the next 2 instances have additional commands after the &F1; I delete
only the &F1 and leave the rest of the reset commands intact)

(3) Save the edited file (mdmusrv90.inf)

(4) Uninstall (remove) the modem from Control Panel->Modems

(5) Add the modem from Control Panel->Modems (do *not* use auto-detect; select from list, select Have Disk, and enter the directory where the edited file resides)

(6) To make sure your modem defaults to the appropriate settings, from a terminal program give the modem AT&F1 (and any other non-factory settings you wish to use) then AT&W.