Sony SRG-120DH Technical Manual page 30

Payload type
Stores the value (Byte 0 and Byte 1) of the following table on the payload division.
Name Value (Byte 0)
VISCA command 01h
VISCA inquiry 01h
VISCA reply 01h
VISCA device setting 01h
command
Control command 02h
Control reply 02h
Payload length
Stores the number of bytes (1 to 16) of data is stored on
the payload.
Example: When the payload length is 16 bytes.
Byte 2: 00h
Byte 3: 10h
Sequence number
The controller stores the sequence number that is
added every time a message is sent. If the sequence
number reaches the limit, next value will be 0. The
peripheral device saves the sequence number in the
message from the controller, and stores the sequence
number of the received message corresponding to the
message sent to the controller.
Payload
Depending on the payload type, the following are
stored.
• VISCA command
Stores the packet of the VISCA command.
• VISCA inquiry
Stores the packet of VISCA message.
• VISCA reply
Stores the reply for the command or inquiry
(Acknowledge message, completion message, or error
message).
• VISCA device setting command
Stores the packet of the VISCA device setting
command.
Value (Byte 1) Description
00h Stores the VISCA command.
10h Stores the VISCA inquiry.
11h Stores the reply for the VISCA command and VISCA inquiry,
or VISCA device setting command.
20h Stores the VISCA device setting command.
00h Stores the control command.
01h Stores the reply for the control command.
• Control command
The following are stored on the payload division of
the control command.
Name
RESET
ERROR
• Controlled reply
The following are stored on the payload division of the
reply for the control command.
Message
Acknowledge
Delivery confirmation
VISCA over IP uses UDP as a communications
protocol of the transport layer. Delivery of messages is
not guaranteed for the UDP communication. Delivery
confirmation and retransmission should be performed
on the application.
When the controller sends a message to the peripheral
device, wait until a reply for the message is received
before sending the next message. You can confirm
delivery of messages by managing the time-out waiting
for a reply message sent.
If time out occurs on the controller, loss of one of the
following messages is considered:
• Command
• Acknowledge message
• Completion message for the command
• Inquiry
• Reply message for the inquiry
• Error message
• Inquiry of the VISCA device setting command
• Reply message of the VISCA device setting command
Command List
Value Description
01h Resets the sequence number to
0. The value that was set as the
sequence number is ignored.
0Fyyh yy=01: Abnormality in the
sequence number.
yy=02: Abnormality in the
message (message type)
Value Description
01h Reply for RESET.
0