My configuration is PM2ER 30 and PM2E30, both with 3.3.1c1 + Multitech MT2834MR.
I recently received a helpful list of settings from Multitech support (which
is included below).Following these settings did lower the rate of
disconnects due to loss of carrier but disconnects due to loss of DTR were
an alarming proportion (up to 40%).
It was not until I forced DTR on the modems (Dip switch 1 down) that this
problem disappeared.
I wonder whether I am actually doing something that is beneficial to my
users? Is there any harm in forcing DTR on?
Best regards
Brynjolfur Thorvardarson
brynthor@treknet.is
>
>
>
> MultiModem Manager Setup 2/14/96
>
>
> The purpose of this document is to assist Internet Service
> Providers(ISP)in setting up the MultiModem Manager for dial in
> access for its customers.
>
>
> Recommended Dip Switches
> ----------------------------------
>
> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
> Up Up Dn Up Up Up Up Up Dn Up Dn Dn Up Up Up Up
>
> Dip 7 must be placed into the up position to allow for the use of
> hardware flow control(RTS/CTS). If using Xon/Xoff, this switch can
> remain in the down position.
> Dip 8 has been placed into the up position to disable the "AT" detect
> mode. If using the modems for dial in only, this switch change will
> not allow the modem to accept "AT" commands from the RS-232 port.
> It will still take config commands from the MultiModemManager and
> the on-line window.
>
> Software Settings
> ---------------------
>
> The current version of the MultiModem Manager is release 4.1. In this
> version the recommended setup is to run the software on a 486/33 with
> a minimum of 8 Meg of memory. This PC should be dedicated to the
> running of MultiModemManager software. Is also recommended no screen
> savers or DOS windows be run while the MMM software is running.
> The software should be configured so the modems are in a defined
> modem group. This is done by adding a defined modem group, and then
> dragging the wanted modems into this group.(See section 3.7
> Organizing your Modems in the MultiModemManager Owner's Manual) The
> Configuration Options checked in the defined Modem Group should be
> configure On Power Up and On Disconnect. By using the software this
> way the modems are assured of being properly configured for every
> incoming call, regardless of how the previous call was terminated.
> The modems should have a configuration file associated with them.
> The config file is going to consist of the options needed to configure
> the modem parameters. In version 4.1 a basic config is already set,
> called ISP.CFG. This file is a good starting point for most
> applications but, you may have to go into the Configuration Manager
> and change the $SB command to match your serial port settings on the
> terminal server.
>
>
>
>
> The file consists of the following commands:
>
> E0 Q2 S13=0 S36=4 S37=5 $BA0 #V1 $SB57600 *H1
>
> The E0 command is to prevent the character echo back to the serial
> port.
>
> The Q2 command will disable the result codes of OK, RING and CONNECT
> from being sent back to the terminal server. These are normally not
> required by the terminal server and can cause problems.
>
> The S13 is the remote config escape character. By setting its value
> at 0 it is disabled and prevents possible hackers from getting into
> remote configuration and changing modem values.
>
> The S36 and S37 registers are values that work together. S36 will
> busy the modem out when DTR is removed for over 4 seconds. After
> the modem has busied out S37 takes over. When DTR has returned for 5
> seconds the modem will be put back into service. This will prevent
> users from ringing a modem where the server is for some reason down,
> disabled, or disconnected.
>
> The $BA0 command, works in conjunction with data compression. Having
> this value at 0 will allow the modem to communicate over the phone
> line at speeds of 300-28800, while keeping the serial port
> communication at 57600. This will allow for higher throughputs.
>
> The #V1 command will disable the V.32Terbo answer tones. This tone
> can cause other vendors modems to try to connect to the V.32 Terbo
> tone and then disconnect.
>
> The $SB command must be set to match the serial port of the system.
> If this value is incorrect users dialing in will get garbage and not
> be able to log on.
>
> The *H1 command will keep the modem off hook during the config process.
> This will help eliminate the possibility of a user calling into a
> modem that has not yet been configured or does not have DTR yet from
> the terminal server.
>
> These commands are edited through the Configuration Manager to match
> the system requirements. Commands may be added, to fine tune the
> operation of the modems as needed. The #F0 command has been shown to
> help if you suspect you have noisy lines or have users complain of
> disconnects and may be added here. A complete listing of the commands
> available are in the Master List.
> Other commands not available, or used in future releases of firmware
> may be added through the use of the User Defined Commands.
> Now assign the config file to the modem(s). This is done by
> highlighting the modems(s), going to the CONTROL menu selection and
> clicking SET MODEM CONFIG FILE. Click the desired config file.
> To view the changes go to Modem Groups and change the Display to
> Modem Configuration and open up the Rack of modems. The config file
> will be displayed next to the modem.
> Now send the config to the modem(s). Do this by highlighting the
> rack of modems or the individual modems then go to the CONTROL menu
> selection and click LOAD CONFIGURATION. Look at the front of the
> rack (if you can) and see the OH led's come on as each individual
> modem gets configured. Now the modems have the correct parameters
> and the software will config them after every call.
>
>
> Hardware Requirements
> ----------------------------
>
> The Management Interface Card is a peripheral device that uses I/O,
> IRQ, and Memory. Installing into a PC that has a lot of peripheral
> devices can be difficult. The most widely used range for the card is
> I/O Port Address of 2E0, IRQ 5, and a Buffer Memory Address of D800.
> The cable between the rack and the card is a standard twisted pair
> phone line. The terminators must be installed for proper operation,
> use of other terminators is not recommended.
>
> The switch settings are as follows:
>
> 1 2 3 4 5 6 7 8 Switches on top of card
> Up Dn Up Dn Dn Dn Up Dn for setting of 2E0, D800.
> \_______________/ \_______/
> Buffer Base
> Address I/O
>
> The Node ID switches are viewable on the back of the card, and
> must all be open in order to operate properly. This will make the
> card ID as 255, and leave the range 0-254 available for racks.
> Anything other than 255, and the managment software will not
> communicate with the rack(s).
> The MR4800 Controller card must also have its own individual address.
> This is done through the switch S1 on the right hand side of the
> controller, the range is 0-254. The default is node 1. The S1
> switch is in hex format (Refer to the MR4800 Rack Controller Manual
> page 2-2 for further assistance).
> When daisy chaining racks together, it is recommended that only
> three racks be attached from each connector on the Management card.
> Any more and a active repeater should be used to compensate for line
> loss. The maximum distance recommended from PC to Rack is 400 feet.
>
>
> Power levels can be measured on the back of the Rack cage between
> slots 14 and 16 just below the phone line interface. The voltage
> at this test point should measure around 5.05 - 5.15 Volts with a
> full rack. Refer to the power supply manual on how to adjust these
> voltage levels.
>
>
> Unmanaged Racks
> ----------------------
> Although we don't recommend it, the MMM rack may also be ran as an
> unmanaged rack. When running this way the controller card should not
> be installed in the rack and the configuration parameters will have
> to be stored (&W) in each modem. After you store the parameters the
> switches should be changed from factory to the recommended dip switch
> settings on page 1.
>
>