Rosen Aviation
Document Number: 100173
Revision: G
Date: 17 April, 2007
Template: 4.2.3-6-FM; Revision A; 16 May, 2005
Page 7 of 10
3.2. Communication Protocol
z
9600 baud
z
8 data bits
z
1 stop bit
z
no parity
3.3. Packet Format
There are typically 3 bytes per message. The first byte is a header byte and the second identifies
the specific command. The third byte is the network address. A network address byte of 0 is
reserved as the “global” address, in other words all slave units should respond to that command.
3.4. Packet Timing
z
Within a message packet, there is a maximum time of 20mSec between bytes.
Messages with bytes sent more than 20mSec apart will not be recognized by the
receiving unit.
z
There should be a minimum elapsed time of 50mSec between any two message
packets. This allows the given processor sufficient time to process the previous
message.
z
Messages sent less than 50mSec apart are not guaranteed to be processed by the
receiving unit.
3.5. Wiring
Rosen Aviation equipment uses a half-duplex wiring layout. Only two RS-485 wires need to be
run between each individual unit. On most products, the RS-485 wires have been internally
daisy-chained so that four external pins exist on the connector.
3.6. Packet Format Descriptions for Single-Disc DVD Control Commands
Byte 1:
0xB0
DVD Control Header
Byte
2:
0x01
“enter”
command
Byte 3:
network id (value between 1-31) 0 is not a valid id for this command.
Byte 1:
0xB0
DVD Control Header
Byte
2:
0x02
“menu
left”
command
Byte 3:
network id (value between 1-31) 0 is not a valid id for this command.
Byte 1:
0xB0
DVD Control Header
Byte
2:
0x03
“menu
right”
command
Byte 3:
network id (value between 1-31) 0 is not a valid id for this command.
Byte 1:
0xB0
DVD Control Header
Byte
2:
0x04
“menu
up”
command
Byte 3:
network id (value between 1-31) 0 is not a valid id for this command.
Byte 1:
0xB0
DVD Control Header
Byte
2:
0x05
“menu
down”
command
Byte 3:
network id (value between 1-31) 0 is not a valid id for this command.
