User manual

Matrix Switching System—User Manual
52
Protocol Byte
Host (PC) command: 1st byte and 2nd byte are fixed.
Byte 1: Device Byte (DB)
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 respond, 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)
Byte 2: Request Byte (RB)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RB
VAR
0
Request Type (0 - 63)
VAR: Variable Length Command Flag.
0 - Standard Command (Recommended)
1 - Variable Length Command. (Only support the command Ack Type A)
Request Type: Please refer to "Table - Host Request List".
A. Standard Command
Byte 3: Index Byte (IB)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
IB
Index
Index: Please refer to "Table - Host Request List" and "Table - Command Index List".
Byte 4: Value Byte (VB)
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
VB
Value
Value: Please refer to "Table - Host Request List" and "Table - Command Value List".