Denon DN-A7100 User Guide - Page 42

ENGLISH TRANSMISSION DATA FORMAT Transmission data format from Host to Slave There are two kinds of transmission data form from Host shown below. • Form1: Command Command is a data that requests some status change. Start character : '@' COMMAND : see "Command list" End character (CR) : 0Dh start command end '@' "xxx:"+"..." 0Dh • Form2: Status request Status request is a data that requests a answer of some status. Start character : '@' Request status : see "Status request list" Request character : '?' End character (CR) : 0Dh start request status end '@' "xxx:?"+"..." 0Dh Transmission data format from Slave to Host There are two kinds of transmission data form from Slave shown below. • Form1: ACK/NAK ACK is a reply data from Slave when Slave got an acceptable command data from Host. (ACK is sent to Host when Slave has no related status by the Command.) Start character : '@', ACK : 06h, End character (CR) : 0Dh start ACK CR '@' 06h 0Dh NAK is a reply data from Slave when Slave got an incorrect Command data, Status request data or some other data from Host. Start character : '@', NAK : 15h, End character (CR) : 0Dh start NAK CR '@' 15h 0Dh THE TRANSACTION SEQUENCES AND THE REGULATIONS The transaction sequences The transactions have three kinds of sequence. * A transaction is a Command from Host then Slave will be an answer by Status answer, ACK or NAK. * A transaction is a Status request from Host then Slave will be an answer by Status answer or NAK. * A transaction is Auto status feedback from Slave when a Slave's status changed. (If the auto status feedback is enabled.) The transaction regulations The transactions have some kinds of regulation. * An answer (ACK, NAK or Status answer) transmittion by Slave has to finish within 500ms when got a Command or a Status request from Host. * Host must not transmit an another Command or Status request until "it receives a answer by a previous Command or Status request" or "it passes a term of waitinng time from a finishing of previous transmission of a Command or a Status request ". * Slave has to finish a transaction under 500ms when it sends Auto status feedback data. Specification of Auto status feedback There are some specific regulations about Auto status feedback. * The product status has segmented into four layers of 1, 2, 3 and 4. * The status of layer 1 are assigned most kindly status to Host. (The statuses of layer 2 are assigned kindly status, the statuses of layer 3 are not so need status to Host and the statuses of layer 4 are probably no wished statuses.) * Each layer status can control transmit enable or disable by Host command. (The product default would be all disables.) * Slave sends auto status feedback by itself when the status is changed and if the status feedback is enabled. * The product defined and segmentationed layers are takeing in status list. Example of the transactions Command max. 0.5 sec TxD Status answer, ACK or NAK Status request max. 0.5 sec RxD Status answer RxD TxD a transaction a transaction Example of the transactions • Form2: Status answer and Auto status feedback Status answers are reply data when Slave got an acceptable Request status or Command data from Host. Auto status feedbacks are send to Host data when a Slave's status is changed. Start character : '@' Answer character : see "Status list" End character (CR) : 0Dh start status end '@' "xxx:"+"..." 0Dh 38