1. An asynchronous multiplex system, comprising: a plurality of first data storage means each adapted to receive a data word into storage therein from a corresponding data source; means coupled with each of said plurality of data storage means for detecting the presence of a data word in any of said data storage means; means for generating a multi-bit data code identifiable with that first data storage means in which the presence of a data word has been detected by said detecting means; second data storage means connected with said generating means and with each of said first data storage means, and adapted to be coupled with a multichannel communication line for storing said data word and data code as single data message therein; and control means coupled with said detecting means, each of said first data storage means, said generating means and said second data storage means, for causing said data word and said data code to be delivered into storage in said second data storage means, and for causing said data message to be delivered from said second data storage means to said communication line for transmission thereon.