Ken Roach said:You will probably have to set up your MSG instructions so they all execute in sequence.
Ok, Ken brings up a good issue that warrants a statement.
For efficient communications, you should be reading/writing an entire set of data to a particular node. Messaging is more efficient if you send a continuous "array" of data versus sending multiple single elements. The way to do this would be to move or copy your data into a dedicated data array to data file that is used for communications.
Another tip would be to only send this "array" on data change.
Don't forget that you should have a "handshake" with the remote node at all times. This way, your controller "knows" the status of the other.