Remote Serial Connection#

Installing the FactoryTalk Remote Access tools on the computer adds a virtual serial port that is required to support the remote serial port virtualization and pass-through function.

This port is mapped by FactoryTalk Remote Access to a physical serial port on your remote PC by using the VPN connection.

Connect the remote serial port#

  1. From the Factory Talk Remote Access service, select the device, and then select VPN.

  2. Once the VPN is connected, open the Remote Desktop and go to the FactoryTalk Remote Access tools.

  3. In the navigation bar, click Connection. The content pane shows the current connection information with three tabs that represent the available connection types; VPN, Serial and USB.


    The connection status of each connection type is appended to the tab name.

  4. Select the Serial tab and click Connect

    • Configure port information as needed to assign the local port to the remote port.

    • Choose the type of encapsulation to use with the connection.

      • Data only: This setting remotes only data; it requires the manual setting of the serial line communication parameters.

      • Data + Port configuration: This setting remotes both data and port configuration; the port will be automatically configured by the system.

      • Data + Port configuration + Data signals: This setting remotes data, port configuration and serial control signals.

    • Choose the Serial line configuration parameters if needed.

  5. Click Connect.

Once you click Connect the local virtual port and remote physical port are virtually connected through Internet. Wait a few seconds until the status on the top of the tab show Serial - Connected.


FactoryTalk Remote Access supports serial pass-through with both half and full duplex connections at remote physical serial port.


Some serial protocols of automation devices are very sensitive to latency, and the remote serial communication could not work, even in the presence of very good connection times.

You can connect only physical serial ports not in use by other applications running on the remote computer.

You must close the applications that lock the serial port before connecting the remote port using FactoryTalk Remote Access.


The proper operation of the serial pass-through is strongly dependent by the Internet connection quality both on FactoryTalk Remote Access service side and FactoryTalk Remote Access tools side.

In quantitative terms, an acceptable roundtrip can be considered to be of the order of 100-120ms. What most affects the proper functioning of the system is the change in ping time that must not exceed 30-40% and the amount of packets lost that must be around zero.