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VISCA Communication
Specifications
VISCA packet structure
The basic unit of VISCA communication is called a
packet. The first byte of the packet is called the header
and comprises the sender's and receiver's addresses.
For example, the header of the packet sent to the FCB-
EX780S/EX780SP assigned address 1 from the
controller (address 0) is hexadecimal 81H. The packet
sent to the FCB-EX780S/EX780SP assigned address 2
Header
Sender's
address
1
Bit 7
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
(MSB)
Command and inquiry
G Command
Sends operational commands to the FCB-EX780S/
SP.
G Inquiry
Used for inquiring about the current state of the
FCB-EX780S/SP.
Command Packet
Inquiry
8X QQ RR ... FF
1)
QQ = 01 (Command), 09 (Inquiry)
2)
RR = 00 (Interface), 04 (camera 1), 06 (Pan/Tilter), 07 (camera 2)
X = 1 to 7: FCB-EX780S/SP address
Packet (3 to 16 bytes)
Message (1 to 14 bytes)
Byte 1
Byte 2
Receiver's address
0
(LSB)
Note
QQ
1)
= Command/Inquiry,
2)
RR
= category code
is 82H. In the command list, as the header is 8X, input
the address of the FCB-EX780S/EX780SP at X. The
header of the reply packet from the FCB-EX780S/
EX780SP assigned address 1 is 90H. The packet from
the FCB-EX780S/EX780SP assigned address 2 is
A0H.
Some of the commands for setting FCB-EX780S/
EX780SP units can be sent to all devices at one time
(broadcast). In the case of broadcast, the header should
be hexadecimal 88H.
When the terminator is FFH, it signifies the end of the
packet.
Byte 3
1
1
1
Bit 7
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
(MSB)
Command List
Terminator
FF
1
1
1
1
1
(LSB)
19
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