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Book Of Connections

Setting up modem Connection

  • Introduction :

    This document describes how to connect a modem to a Printronix printer (P5000, T5000 and L5000 with LVX Controller), and how to configure the modem and printer for remote ATK sessions through a telephone connection. The drawing below shows how the communication between the host computer running ATK and the remote printer is set up:

     

    modem

     

    Most modems use the AT command set for configuration and initialization. Before the communication start, the connected system or printer will send out a command string to initialize the modem. Unfortunately, there are many variations on the AT command set which makes it impossible to define a universal initialization string that will work on all modems. It has therefor been decided to implement two options : Use an initialization string that is recognized by the modems manufactured by USRobotics ( division of 3Com ), or send out a reset string which resets the modem and loads the configurations that has been stored in the modems novram profile number 0. The latest option requires that the user configures the modem using a terminal ( or terminal emulation program ), and save that configuration in the modems novram before connecting the modem to the printer.

     

    Using a USRobotics modem:

     

    When turning on the printer, the printer will send a command string out the selected diagnostic port to initialize an attached modem. When the printer configuration is set up as shown below, and a cable is used as specified in the cabling section, USRobotics modems should not need to be configured to operate with Printronix printers. The only important note here is the power-up sequence: the modem needs to be turned on first, as during the power-up sequence of the printer, the printer tries to find the modem by sending out the initialization string. If the modem is off, it will not respond, and the printer will not detect the modem. If the modem is detected, this will be shown on the LCD by displaying the 'MODEM DETECTED' message just before the printer goes on-line.

     

    Printer configuration: ( See "Configure the Printer" )

     

    Diagnostic port 'Serial'
    Select port 'Host' or 'Debug' (Depending on where the modem is attached to)
    Modem 'Enable'
    Modem NVM 'Disable' (Printer will send out the USRobotics initialization string)
    Modem Status 'Enable' (Printer will show modem status: Ring, Carrier, etc.)
    Dial Method 'Tone' or 'Pulse'.

    If for some reason, the US-Robotics modem that you use is not detected by the printer, you can try to configure the modem manually, and use the Modem NVM enable setting to use that configuration. Refer to the next section on how to manually configure the modem.

     

    Manually configure the modem:

     

    This section describes how to configure a modem before it is attached to the printer. To configure the modem and save the configuration in the modem's novram proceed as follows:

    1.  Connect the modem to a serial port of your computer, using a standard modem cable (the cable that came with your modem).

    2.  Now start a terminal emulation program that is capable of communicating with the serial port to which the modem is attached. Examples of a terminal emulation programs are HyperTerminal (comes with Windows) and Procomm.

    3.  Configure the terminal emulator to communicate directly to the serial port to which you attached your modem (do not configure it to talk to a modem attached to this port).

    4.  Turn on the modem, and enter 'AT' in the terminal window. The modem should now respond with 'OK' or '0'. If not, check if you configured the terminal program for the correct serial port. If this appears to be correct, check the selected baud rate in the program's properties. It could be set to a value which is not supported by your modem, or that your modem's baud rate is fixed to a value that does not match the terminal's baud rate.

    5.  Once you get the 'OK' or '0' response from your modem, you can proceed with the configuration by typing some AT commands. You best type them one by one to see if the modem responds correctly on each command. Note that the commands listed are the commands used for US-Robotics, which may not work on other modems. Refer to the manual that came with your modem to see which commands should be used for the described functions.

    Description of command: Command on USR modems:
    Echo off ATE0
    Verbal (text) responses on commands ATV1
    Modem speaker always off ATM0
    Transmit data flow control: X-On/X-Off AT&H2 Or AT&K4
    Receive data hardware flow control: ignore RTS AT&R1
    Control DTR operations: DTR override AT&D0
    Auto-answer on first ring ATS0=1

    It may be necessary to send one more command to adapt your modem to the local phone system. If you bought your modem locally, the default configuration will probably be correct. Otherwise, refer to your modem manual which command is used to configure for the correct phone systems (many modems, including USR, use the command ATBn for this configuration).

    6.  When the modem has correctly been set up, save the configuration in the modem's non-volatile memory (novram) in profile number 0 (many modems, including USR, use the AT&W0 command). This profile will get loaded when the printer is turned on: The printer will send out the ATZ0 command to load profile number 0.

    You have now configured your modem. Turn the modem off, and connect it to the printer, using the modem cable as specified in the cabling section. The modem can be connected to either the debug serial port or the host serial port ( do not use the T5xxx debug port when a validator is used ). Make sure the following settings are made in the diagnostic port sub-menu of the 'hidden' printer configuration by doing the following:

    Configure the Printer:

     

    Set printer 'Off-Line'.
     
    P5000:
    • Unlock the control panel, by pressing: 'Up and Down' keys simultaneously.
    • Access the hidden Diagnostic menu, by pressing 'Up, Down, Left and Right' keys simultaneously.
    • Press the 'Next' key, till 'Printer MGMT'
    • Press the 'down' key to access 'Diagnostic Port, where you can define the following:
     
    T5000:
    • Unlock the control panel, by pressing: 'Enter and Down' keys simultaneously.
    • Go with the 'Menu' key to Printer Control.
    • Go to Advanced user and select 'Enable'
    • Go again with the 'Menu' key to Printer Control and go to Host Interface and select 'Ethernet' or 'Centronics'.
    • Access the hidden Diagnostic menu, by pressing 'Previous, Next, Up and Down' keys simultaneously.
    • Press the 'down' key to access 'Diagnostic Port, where you can define the following:
     
    L5000
    • Unlock the control panel, by pressing: 'Up and Down' keys simultaneously.
    • Access the hidden Diagnostic menu, by pressing 'Up, Down, Prev and Next' keys simultaneously.
    • Press the 'Next' key, till 'Printer MGMT'
    • Press the 'down' key to access 'Diagnostic Port, where you can define the following:

     

    Diagnostic port 'Serial'
    Select port 'Host' or 'Debug' (Depending on where the modem is attached to)
    Modem 'Enable'
    Modem NVM 'Enable' (Printer sends ATZ0, and not an initialization string)
    Modem Status 'Enable' (Printer will show modem status: Ring, Carrier, etc.)
    Dial Method 'Tone' or 'Pulse'.

     

    Note that the power-up sequence is important: the modem needs to be turned on first, as during the power-up sequence of the printer, the printer tries to find the modem by sending out the ATZ0 string. If the modem is off, it will not respond, and the printer will not detect the modem. If the modem is detected, this will be shown on the LCD by displaying the 'MODEM DETECTED' message just before the printer goes on-line.

     

    Cabling:

     

     
    Cable for connecting modem to Printers Serial Debug Port
    Cable for connecting modem to Printers Serial Host Port