... the MDB Bill Acceptor and MDB Coin Changer data to RS-232 data to PC. Bill acceptor and coin validator ... to the Master's request (polling) consists of a header and data bytes. If there is no BA or CC activity ... , the status is one byte, the header only. When the IU receives data from the BA or CC, it sends ... a header followed by data bytes in the response to master's status request ...