The way your network peripherals are handled during different power modes is not controlled by Trader Workstation but by the operating system installed on your machine. Usually the network peripherals will also be put on a low power saving mode when the machine enters Sleep or Hibernation power states, and this will cause the existing network connections to be terminated.
Normally each operating system allows the user to have a certain level of control over the peripherals behavior during low power modes. Hence it might be possible for you to tweak some system settings to prevent the network interfaces from entering the power saving mode. However, this may not work or may not be available for your system. Sometimes the only way to avoid having network connections terminate is to prevent your computer from entering Sleep/Hibernation modes.
We suggest you search the Internet and explore the possibilities available to you, according to your specific operating system. Or, contact your local PC support should you prefer to obtain assistance in this way.