Protocols & Ports used

DHD systems use two network protocols for communication with other DHD systems or with a PC. A direct TCP/IP connection is used for direct data transfers from a DHD system to a PC or vice versa, e.g. for downloading a configuration or for updating the firmware. All optional DHD software applications (e.g. DHD Operation Manager) also base on direct TCP/IP connections.

In contrast, the UDP protocol is used for the following functions:

  • Global Logics
  • Global Potentiometers
  • Global Resources
  • General system messages in the Maintenance Window and in the DHD Communication Server

Since the UDP protocol is connectionless, the sender does not receive an acknowledge for the transmitted data from the receiver. The operating system of a DHD device does not directly send UDP data to certain destination addresses. Instead, it uses the Broadcast address to send data to all network nodes within the same subnet. All receiving nodes analyze the contents of the received UDP packets and react accordingly, if necessary.

For the communication to work properly, the network ports 2008, 2009 and 3008 need to be enabled both for TCP and UDP. Make sure you set up routers, firewalls and other security applications accordingly.

Control Link makes use of standard communication ports 2008, 2009, 3008 as specified below.

The ports are used as following:

Port Description
Port 80HTTP connections for system maintenance and Web Apps
Port 2008TCP/IP connnections to Series 52 DHD systems via DHD External Control Protocol (DHD ECP) and to RM4200D DHD systems
Port 2009Transfer of UDP packets to Series 52 DHD systems and to RM4200D DHD systems.
Port 3008TCP/IP connnections to Series 52 DHD systems.
Port 9000 TCP/IP connections to the Ember+ protocol interface of Series 52 DHD systems