Equisys technical notes

Technical guidance, explanations and fixes for our products

HOWTO: Installing a Multitech ZBA USB modem with Zetafax



ID: ZTN2081

This Zetafax technical note applies to:

  • Zetafax 2014
  • Multitech Multimodem ZBA modem (model number MT9234ZBA-USB-CDC-XR)


Zetafax can be used with a compatible fax modem for sending and receiving faxes.  These can be a cost effective option for systems with a single analog fax line, and which do not require the more advanced features available with specialist fax boards and other telephony options.

If the Zetafax server computer has a serial (COM) port available, then we would recommend using a modem with a serial port connection such as the Multitech Multimodem ZDX.  However if the server computer does not have a serial port then an alternative option is to use a USB modem.

Equisys have tested Zetafax with the Multitech Multimodem ZBA, which is a USB fax modem designed for use with use with communication server products.   This document gives instructions on how to install and configure this modem for use with Zetafax.

More information

To use a Multitech ZBA USB modem with Zetafax the following steps are required:

  • Connect the modem to the Zetafax Server computer and phone line
  • Download and install the Multitech Windows drivers for the modem
  • Add a Zetafax device for the modem
  • Test the installation

These steps are described in more detail below.

Step 1 – Connect the modem to the Zetafax Server computer and phone line

Position the modem close to both the Zetafax Server computer and a suitable phone line socket.  If possible, ensure that the front panel is visible to help with initial configuration and testing, though this should not be necessary in normal usage.

Connect the modem to the phone line using the supplied cable.  There are two identical ports on the back of the modem – ensure that the phone line is connected to the port labelled LINE.

Now connect the modem to a spare USB port on the Zetafax Server computer, using the supplied USB cable.  Note that once the system has been configured the modem must always be connected to the same USB port on the computer.

If the modem is moved to a different USB port it will appear as a new device within Windows.  This will result in the Zetafax Server being unable to communicate with the modem until the device is re-configured within Zetafax, or moved back to the original USB port.

With later Windows versions you may see a notification from Windows that it is installing drivers from the device.  Wait for this to complete before continuing – this may take several minutes.

Step 2 – Download and install the Multitech Windows drivers for the modem

Visit the Multitech web site and find the Windows drivers (or “installation files”) for the modem.  The model number for the Multimodem ZBA device as tested is MT9234ZBA-USB-CDC-XR, and the download page (current at time of publication) is:


Download the installation file package, then extract (decompress) the installation files and save them in a folder on the Zetafax Server computer.

Follow the installation instructions in the user guide which is available on the same location.  If you are installing on Windows 8, Windows 8.1 or Windows Server 2012 and the installation guide does not contain explicit instructions for that operating system, then follow the instructions for Windows 7 instead.

The Windows drivers add a “virtual COM port” for the modem, which Zetafax will use to communicate with it.  When the installation is completed, you can check that this has been added correctly by running Device Manager from the Windows Control Panel.  You should see a section labelled Modems, including the Multitech modem:

Displaying properties for that device will display the Virtual COM port associated with the device.

The properties screen also enables you to test communication with the device, using the Diagnostics tab.  Note that once the modem has been configured in Zetafax has been added in Zetafax then the Zetafax Server must be stopped or the device set to Offline before testing communication in this way.

Step 3 – Add a Zetafax device for the modem

The next step is to add a device within Zetafax to use the modem. 

If the Zetafax Server software has already been installed, run the Zetafax Configuration Program, right-click on the Devices section, then choose Add to display the device configuration wizard.  If the Zetafax Server software has not yet been installed, then install it now and the device configuration wizard will be displayed automatically.

Zetafax now checks for any modems on this computer which have not yet been configured.  Provided the USB modem drivers have been installed correctly and the modem is connected, then the wizard will display a page asking whether you wish to configure and installed modem or another device.

If this screen is not displayed or the wizard goes straight to the “Other Device Types” screen, then check that the Windows drivers have been installed correctly (previous step), and that the device is connected.

Choose Search for installed modems then click Next to display the list of detected devices.

Select the Multitech ZBA modem (MT9234ZBA-USB), then click Add to display the device configuration screen,

You can configure the device so that it can be used for sending and receiving faxes, or is reserved for just one of these operations.  For systems which are used for receiving faxes it is often advisable to have at least one device reserved for incoming faxes, so that you can still receive faxes if a large number of faxes are queued for sending at the same time.

Configure the device as required, then click Next save the settings and complete the wizard.

Step 4 – Test the installation

The device should now be installed and ready to use with Zetafax.  To test the installation, do the following:

  • Start (or restart) the Zetafax Server program.  Check that the device is shown as Online in the device list window, and check that there are no errors reported by the FCLASS device controller program.
  • Send a fax to a test number (if you have enabled sending from the device).  Check that the fax sends correctly, and there are no errors reported by the FCLASS device controller program.  Note that if the Zetafax Server is configured with a single fax line then you will need to use a separate number for testing.
  • Send a fax from another number to the Zetafax Server (if you have enabled receiving on the device).  Check that the fax is received correctly, and that no errors are reported by the FCLASS device controller program.


Further details of the this modem can be found on the Multitech website www.multitech.com

Last updated: 23rd January 2015 (GW)

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