№
SX-DCT00221 -
45-
Panasonic Corporation
13-6. Transmission sequence
●
Handshake code
For line control, following codes are used:
Name
Code
Functions
Description
SOH
01h
Heading start
Start code of communication data, which is followed by address.
STX
02h
Text start
Start code for sending command data.
ETX
03h
Text end
Termination code for command data.
EOT
04h
Transmission end
Sent from the amplifier when transmission message is finished.
ENQ
05h
Request for sending
Inquiry code from host controller to amplifier. The amplifier sends
data transmission command when sending data is available, and
transmission end command when sending data is not available.
ACK
06h
Positive response
Sent when received message is judged to be normal.
NAK
15h
Negative response
Sent when received message is judged to be abnormal.
●
Composition of sent and received data
Shows composition of data transferred on physical phase.
There are two transmission patterns available depending on the contents of command.
Request for sending/ Positive response/
Negative response/ Transmission end command
(Host
→
Amplifier, Amplifier
→
Host)
Data transmission command
(Host
→
Amplifier, Amplifier
→
Host)
SOH
SOH
Sending address 1
Sending address 1
Sending address 2
Sending address 2
Senders address 1
Senders address 1
Senders address 2
Senders address 2
ENQ/ACK/NAK/EOT
STX
Command 1
Command 2
Data number 1
Data number 2
Data number 3
Data number 4
Data 1
Data 2
Data 3
Data 4
ETX
BCC
Sending address: Set the mating device number for sending data in ASCII2 byte.
Host ID 01h (01) - 1Fh (31)
Amplifier ID 80h (128) - 9Fh (159)
When the sending address is set to 80h (128), all connected amplifiers executes
the command (only for some commands). However, response is not made
from the amplifier
Senders address: Set the address of communication sending source (self) in ASCII 2 bytes.
Host ID 01h (01) - 1Fh (31)
Amplifier ID 81h (129) - 9Fh (159)
Command : Control command (2 bytes)
Data number : Set the data number to be controlled in ASCII 4 bytes.
Data : Set the writing data in ASCII 4 bytes.
When data is minus, it is converted by signed 16 bits.
(e.g. In the case of -10, data is ASCII code of hexadecimal FFF6.)
BCC
:
:n the case of data transmission command, set XOR (logically inverted) value of each byte from STX to
ETX.