UDP send and receive blocks function as sender and receiver blocks following UDP protocol in all the toolboxes.
The difference between them is that blocks are adapted as per the toolbox in which they are included.
UDP blocks in Instrument Control toolbox are meant for interface-based communication (creating an object of the interface type here UDP interface) to connect to the instrument. Whereas UDP block in Embedded Coder Toolbox are meant for code generation. For example, UDP blocks from the Instrument Control Toolbox are not supported for code generation but blocks from Embedded Coder does.