UDP Connection

To create a UDP connection, do the following:

  1. Select New connectionUDP connection on the toolbar:

    sec-create-udp-300x226

  2. Specify the connection name.
  3. Choose the local COM port to be used in the connection.
  4. Check Create as virtual port if you want a virtual COM port to be created for this connection.

    Virtual ports work exactly like real ones and fully emulate their settings. Their main advantage is speed and also the fact that you can create any number of virtual ports you want and with arbitrary names.

    Note: a virtual COM port can have the same name as an existing real port. In this case the virtual port will “overlap” the real one, with the latter becoming inaccessible to other applications.
  5. Enable Strict baudrate emulation if you checked Create as virtual port and expect to send data in large blocks (2 KBs or more). This will limit the baud rate of the virtual port to the value it is actually opened with and will usually prevent potential data loss.
  6. Check Use different port to receive data if you want data from remote hosts to be received on a different UDP port than it is sent.
  7. Under Remote host name and Port specify the name or IP address of the remote host(s) along with the UDP port to send data to.
    Note: The UDP ports you select should be allowed by your firewall and should not be already in use by another application.
  8. Configure the advanced settings, if needed (see the next section).
  9. Press Create connection.

After that, you can create a connection of the same type on a remote host.

Advanced Settings

The advanced settings are grouped into two sections: Connection preferences and Signal lines. The rest of this page covers them in detail.

Connection preferences

Default port settings:

If specific port settings are expected by the device attached to your real COM port, you can set them here.

Note: If the Create as virtual port option was checked, Default port settings will be greyed out, as in this case the settings are to be defined by the application that opens the COM port.

Data transfer settings:

  • Receive data from:
    • None – no data will be accepted from any remote host.
    • Only first / Only last – data will only be accepted from the remote host that is currently first / last in the list.
    • Last active (incl. not on list) – data will only be accepted from the remote host from which it was received last, even if that remote host is not added to the list.
    • All – data will be accepted from all remote hosts (default).
  • Send data to:
    • None – no data will be sent to any remote host.
    • Only first / Only last – data will only be sent to the remote host that is currently first / last in the list.
    • Last active (incl. not on list) – data will only be sent to the remote host from which it was received last, even if that remote host is not added to the list.
    • All – data will be sent to all remote hosts (default).
Tip: In case you are wondering about the Telnet protocol, it cannot be used with UDP due to its connectionless nature. For more on the differences between TCP and UDP, check for instance this Wikipedia article.

Connection settings:

  • Add pause between packets – wait for the specified time after every network packet sent.
  • Before sending data wait for – accumulate all data in a buffer for the specified time before sending it out to the network.
  • Send out the data when the block is – accumulate all data in a buffer and send it only when it reaches the specified size.
  • Send data when received char with code – accumulate all data in a buffer and sent it only when a character with the specified ASCII code is received.

Signal lines

In this section you can configure the line states of the local COM port. For real ports you can set the states of the DTR and RTS lines, for virtual – DSR, CTS and CD.