Skip to content
Ask A Question
  • There are no suggestions because the search field is empty.

Connecting to GE 90/30 Controller via CMM 321 Ethernet module on Windows Vista / 2008 / 7 Operating Systems

A server project running on a Windows 2003 / XP or older operating system can connect to and receive data from the GE controller without any problems, but fails when running on a Windows Vista or higher operating system.

The likely issue here is that the dynamic source port range used by the Windows operating system exceeds the range of source ports that are allowed by the GE CMM communications card for connectivity.

Windows 2003 and older operating systems have a default dynamic source port range of 1025 to 5000. These ports are assigned by the operating system to the server when it asks to create a socket for communications with a device. To comply with Internet Assigned Numbers Authority (IANA) recommendations, Microsoft has increased the dynamic client port range for outgoing connections in Windows Vista, Windows Server 2008, and Windows 7. The new default start port is 49152, and the default end port is 65535.

GE CMM321 communications models running older Firmware versions do not support this new range of ports as source ports on connections.

Options for Resolving This Issue

  1. Update the communications card's Firmware if possible. (Preferred Method)
  2. Change the operating system's dynamic source port range using the netsh command. For operating system specific instructions for changing this range, see the steps below.

If option 2 is used, this process will need to be repeated if the operating system is reinstalled or the server PC is replaced for any reason.

Windows Vista and 2008 Server Netsh Commands

  1. Start by opening a DOS command prompt.
  2. Type netsh int ipv4 show dynamicport tcp and press Enter.  (This will display the current default port range settings - Starting Port Number and Number of Ports)
  3. Now, to change these settings, type netsh int ipv4 set dynamicport tcp start=xxxxx num=yyyyy and press Enter, where:
    • xxxxx is the desired Starting Port Number, and
    • yyyyy is the Number of Ports.
    Using the range supported by Server 2003 and earlier operating systems should allow you to communicate but you will want to check with an IT Manager for the desired ranges to be used.
  4. Once the port range has been set, the operating system will return an OK confirmation message.
  5. Restart the operating system to apply the changes.

Windows 7 Netsh Commands

  1. Start by opening a DOS command prompt.
  2. Type netsh int ipv4 show dynamicportrange tcp and press Enter. (This will display the current default port range settings - Starting Port Number and Number of Ports)
  3. Now, to change these settings, type netsh int ipv4 set dynamicportrange tcp startport=xxxxx numberofports=yyyyy and press Enter, where:
    • xxxxx is the desired Starting Port Number, and
    • yyyyy is the Number of Ports.
    Using the range supported by Server 2003 and earlier operating systems should allow you to communicate but you will want to check with an IT Manager for the desired ranges to be used.
  4. Once the port range has been set, the operating system will return an OK confirmation message.
  5. Restart the operating system to apply the changes.

Check with the IT/Network Manager to ensure there are no group policies in place that will prohibit the PC's dynamic port range from being changed and for the suggested starting and ending port numbers to be used.