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 camera assigned address 1 from the controller (address 0) is hexadecimal 81H. The packet sent to the camera
Command List
assigned address 2 is 82H. In the command list, as the header is 8X, input the address of the camera at X. The header of the reply packet from the camera assigned address 1 is 90H. The packet from the camera assigned address 2 is A0H.
Some of the commands for setting cameras 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.
Packet (3 to 16 bytes)
Header |
|
| Message (1 to 14 bytes) |
|
| Terminator | ||
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Byte 1 | Byte 2 | Byte 3 |
|
|
| FF |
|
|
|
|
|
|
|
|
|
|
|
|
| Sender’s |
|
|
|
|
|
|
|
| ||||
|
|
|
| address |
|
|
|
|
|
|
|
|
|
| ||
1 |
|
|
|
|
| 0 | Re | ceiver’s addre | ss | |||||||
|
|
|
|
|
|
|
| |||||||||
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Bit 7 Bit 6 |
| Bit 5 Bit 4 Bit 3 | Bit 2 Bit 1 Bit 0 | |||||||||||||
(MSB) |
|
|
|
|
|
|
|
|
|
| (LSB) | |||||
1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
|
|
|
|
|
|
|
|
Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
(MSB) |
|
|
|
|
|
| (LSB) |
Command and Inquiry
●Command
Sends operational commands to the FCB camera.
●Inquiry
Used for inquiring about the current state of the FCB camera.
| Command Packet | Note |
Inquiry | 8X QQ RR ... FF | QQ1) = Command/Inquiry, |
|
| RR2) = category code |
1)QQ = 01 (Command), 09 (Inquiry)
2)RR = 00 (Interface), 04 (camera 1), 06 (Pan/Tilter), 07 (camera 2)
X = 1 to 7: FCB camera address
40