get a send/receive method within an external

The clean way to do this is having your object A directly calling methods of B. This is straightforward (use object_method in one of its flavors) as long as A knows the memory address of B – which can be accomplished in a variety of ways (according to how you want your objects to be aware of each other), including binding B to a symbol:
gensym("my_B_object")->s_thing = x;
or iterating the patcher…

On a side note, but this is strictly personal, I don’t like wireless communication in Max. I am suspicious about the pattr system, value, pv and even send/receive, I use them as little as I can… I think they really work against the Max paradigm… but, then again, that’s just me… ;)

aa

Hi,

to accomplish a mechanism like send/receive, you need to use the object notification system of Max. Unfortunately, the usage of this is quite splitted up within the documentation (at least, this was the case in the Max 5 SDK — I don’t know if the situation changed with Max 6, as I still did not make that step). I implemented a generic “stream” object (an object capable of streaming bytes between externals that use my interface) within The sadam Library a few years ago, using the globalsymbol/object_notify/object_method stuff. On the one hand, you may wish to experiment with using that one; although my project is closed-source, the header file describing the interface of my streaming object is public, and the documentation contains a chapter explaining how to use it. On the other hand, you may wish to read the forum thread where I summarized the key points of attaching to/detaching from named objects (along with the links mentioned by Nicolas): http://cycling74.com/forums/topic/globalsymboling-issues (and, as a small addendum: http://cycling74.com/forums/topic/object_notify-and-thread-safety ).

Hope this helps,
Ádám