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Payload:
According to Payload type, the following data will be saved.
VISCA command: Save VISCA command packet
VISCA inquiry: Save VISCA message packet
VISCA reply: Save VISCA return packet
VISCA device setting command: Save VISCA equipment setting command packet.
Control command: The following data is saved in control command payload
Control reply: The following data is saved in the return command payload of control command.
Delivery confirmation:
VISCA over IP uses UDP transmission communication protocol. UDP communication message
transmission is not stable, it is necessary to confirm delivery and resent in application.
Generally, when controller sends a command to camera, controller will wait for the return message then
send the next command. We can detect and confirm if the camera receives the commands within its return
message’s lag time. If controller detects overtime, it is regarded as error transmission. Controller will resend
the commands to check camera’s status. The resent command sequence number is the same as the previous
one. Following chart lists possible received message and the corresponding status after the resent command.
Lost message
Received message
for retransmission
Status after
retransmission
Correspondence after
retransmission
Command
ACK message
Command is
performed by
retransmission.
Continue processing.
Completion
message
For the
command
ERROR
(Abnormality in the
sequence number.)
Command has been
performed.
If only the ACK
message is lost, the
completion
message returns.
If the result by the completion
message is needed, retransmit by
updating the sequence number.
Completion
message for
the command
ERROR
(Abnormality in the
sequence number.)
Command has been
performed.
If the result by the completion
message is needed, retransmit by
updating the sequence number.
Inquiry
Reply message
Inquiry is
performed by
Continue processing.
Name
Value
Description
RESET
0x01
Resets the sequence number to 0. The value that was set as the
sequence number is ignored.
ERROR
0x0Fyy yy=01: Abnormality in the sequence number.
yy=02: Abnormality in the message (message type).
Message
Value
Description
ACK
0x01
Reply for RESET.
