Sony FCBEH3300 Product Manual (Tehnical Manual for new HD Block Cameras) - Page 28

Command List 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 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. Header Packet (3 to 16 bytes) Message (1 to 14 bytes) Byte 1 Byte 2 Byte 3 Terminator FF Sender's 1 address 0 Receiver's address Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 B it 2 B it 1 B it 0 (MSB) (LSB) 1111 1111 Bit 7 Bit 6 B it 5 B it 4 B it 3 Bit 2 B it 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 28