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APPENDIX C RS-232 COMMUNICATION PROTOCOL
This AV Matrix RS-232 communication protocol uses fixed length with 5 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 Switcher device. The computer can control the Switcher
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.
D-1 Host Request
A standard command is 5 bytes:
R 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)
Host must send CRC code to follow the last byte.
D-1.1 Device Byte
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DB
BT
0
1
Device ID (0 - 31)
BT:
Broadcast Command Flag.
0 - Instruction for Device ID only
1 - Instruction for all devices. (Device ID must be written 0)
Devices will not response, when receiving the broadcast command.
0: Reserve, Always 0.
1: Identifier, Always 1.
Device ID:
Device id ranges from 0 to 31. (Please refer to device’s user manual)
