User manual

Matrix Switching System—User Manual
51
Appendix C RS-232 Communication Protocol
This AV Matrix RS-232 communication protocol uses variable length bytes of information
as define below. The default baud rate is 9600 bps, no parity, 8 data bit and 1 stop bit.
Command timeout is 300 ms, and byte to byte timeout is 30ms.
Use the RS-232 connecting cable to connect the computer serial port to the RS-232
communication port of the matrix device. The computer can control the matrix device via
RS-232. Aside from using the front panel keys for operation, you are also permitted to
use the RS-232 connection port for remote operation.
Protocol Command
A. Standard Command
Standard command is 5 bytes command.
Device + Request + Index + Value + CRC
Byte 1: Device Byte (DB)
Byte 2: Request Byte (RB)
Byte 3: Index Byte (IB)
Byte 4: Value Byte (VB)
Byte 5: CRC Byte (CB)
B. Variable Length Command
Variable length command is 2n+4 bytes command.
Device + Request + Length + Index 1 + Value 1 + … + Index n + Value n + CRC
Byte 1: Device Byte (DB)
Byte 2: Request Byte (RB)
Byte 3: Length Byte (LB)
Byte 4: Index 1 Byte (IB
1
)
Byte 5: Value 1 Byte (VB
1
)
Byte 6: Index 2 Byte (IB
2
)
Byte 7: Value 2 Byte (VB
2
)
… … … … …
Byte 2n + 2: Index n Byte (IB
n
)
Byte 2n + 3: Value n Byte (VB
n
)
Byte 2n + 4: CRC Byte (CB)
 Host must send CRC code to follow the last byte.