Is there anyone help me?

What are you trying to do?

The term "DAB" is generally an abbreviation for "Digital Audio Bus". In the context of the NION there are two different digital audio buses to be considered, the IDAB (or Internal Digital Audio Bus within each NION) and the XDAB (or eXternal Digital Audio Bus, used to share audio between NIONs within a rack at extremely low latency). Either of these DAB's do not have anything to do with sending control messages.

If you simply want to send a TCP message from your project to a computer somewhere on the network to tell it to do something, you may want to look at using the Comms Processor. I need to know what you are trying to do before I can even consider assisting you.

Thanks!