The Asynchronous Message Communication (AMC) Reference Library is a general purpose LabVIEW API for sending messages within a process, between processes, and between different LabVIEW targets (systems on a network) in a LabVIEW application.
I think its the newer version of AMC that added this, but either way when using it across the network the port information is encoded in the "receiver host" string. So when your target gets a message, it knows what port to send it back on (if not the default). Unfortunately, the rest of the library doesn't seem to use this at all, so for as far as I can tell, the user must manually parse blah out of the string, convert that into a number, and then use that number to respond, or else it will not reach its destination. Using package 3.3.1.22 but it seems to be an issue in the source as well.
I think its the newer version of AMC that added this, but either way when using it across the network the port information is encoded in the "receiver host" string. So when your target gets a message, it knows what port to send it back on (if not the default). Unfortunately, the rest of the library doesn't seem to use this at all, so for as far as I can tell, the user must manually parseblah out of the string, convert that into a number, and then use that number to respond, or else it will not reach its destination. Using package 3.3.1.22 but it seems to be an issue in the source as well.