Haxxio UDP Serial Port Redirector
UDP Transmit Mode Selection
Field Specific Help
This selection controls how the Redirector sends data.


There are five distinct transmission modes.

Transmission Mode Description
No transmissions Exactly what it says - the Redirector will not transmit any data to the network. Any data sent by your application to the virtual serial port will be discarded.
Reply to last sender Each time a packet is received by the Redirector, it notes the source address of that packet. All subsequent transmissions by the Redirector will be made to that source address.


This can work very well for a many-to-many type scenario, see the Groups of PCs and/or terminal Servers communicating example. However, the Timer Interval Selection must be set short enough that data intended for different recipients doesn't get jumbled into the same packet.


If all the devices are on the same network (or more correctly, on the same broadcast domain) and the application uses some sort of device addressing, so it can tell serial data streams apart, the broadcast mode may work better.

Reply to first sender The source address of the first packet will be captured, and all replies sent to that address.


This mode is most useful when there is only one other communicating device on the network, and for some reason (eg DHCP assignment) you don't know what it's address is.

Broadcast replies This is one of the most useful modes, as it allows a group of devices on the same network (or more correctly, on the same broadcast domain)to communicate without further setup.
Send to fixed address This mode specified the address of the communicating device. This is generally used in one of two situations


a) A point to Point serial link, where both end-points know their address and that of the opposing party. See the example Replacing a Serial Cable


b) Where this station is one end (indeed the "one" end) of a many to one scenario. The other endpoint (the "many" will probably use either "broadcast replies", or possibly "reply to last sender"


Unless "No Transmissions" is selected, then the address to which the Redirector is transmitting is shown by the Remote IP Address field.

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