Focus Firestore FS-M, Руководство пользователя

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MANL-0977-01 Review Draft - FS-M User Manual
45
Transfer Mode
6.3.3.1 Track command
The
Track
command plays a selected track. The command structure
includes both the command block and a data block containing the track
ID.
6.3.4 Data Transfer Protocol
The data transfer protocol provides a method that permits the sending of large or
small amounts to data between the Host and the FS-M. The process is described
below:
1.
The Host issues a command to the FS-M to initiate a data transfer.
The type and quantity of data returned depends on the command.
2.
The FS-M collects the requested data and parses it into 255-byte data blocks.
3.
The FS-M returns a
Transfer Data Size
message to the Host with the total size in
bytes of the data about to be sent.
4.
Host confirms size of the data transfer by returning the data size to the FS-M.
5.
The FS-M sends the data in a series of
Transfer Data Packets
. As an error check-
ing method, each packet includes a checksum of its data.
6.
The Host receives and reassembles the data.
7.
The Host verifies data integrity using the checksum and returns it to the FS-M,
indicating the successful receipt of the data packet.
8.
When done, the FS-M issues a command reply message back to the Host.
6.3.4.1 Transfer Data Size
6.3.4.2 Transfer Data Packet
Transmit Reply
STX DIG: X ETX STX DIG ETX
X
is the track number: 1 - 999.
Transmit Reply
‘L’ Data Size ETX ‘L’ Data Size ETX
Transmit Reply
‘T’ Byte Size Data Checksum ETX Check sum