Through the group policy settings, you can configure serial port redirection and control the extent to which users can customize redirected COM ports. Your choices depend on the user roles and 3rd-party applications in your organization.
For details about the group policy settings, see Serial Port Redirection Group Policy Settings.
If your users run the same 3rd-party applications and COM port devices, make sure that the redirected ports are configured in the same way. For example, in a bank or retail store that uses point-of-sale devices, make sure that all COM port devices are connected to the same ports on the client endpoints, and all ports are mapped to the same redirected COM ports on the remote desktops.
Set the PortSettings policy setting to map client ports to redirected ports. Select the Autoconnect item in PortSettings to ensure that the redirected ports are connected at the start of each desktop session. Enable the Lock Configuration policy setting to prevent users from changing the port mappings or customizing the port configurations. In this scenario, users never have to connect or disconnect manually and cannot accidentally make a redirected COM port inaccessible to a 3rd-party application.
If your users are knowledge workers who use a variety of 3rd-party applications and might also use their COM ports locally on their client machines, make sure that users can connect and disconnect from the redirected COM ports.
You might set the PortSettings policy setting if the default port mappings are incorrect. You might or might not set the Autoconnect item, depending on your users' requirements. Do not enable the Lock Configuration policy setting.
Make sure that your 3rd-party applications open the COM port that is mapped to the remote desktop.
Make sure that the baud rate that is in use for a device matches the baud rate that the 3rd-party application is attempting to use.
You can redirect up to five COM ports from a client system to a remote desktop.