You can control the monitor settings using VMC packets
superimposed on SDCP. A VMC packet is applied to
the Data field of an SDCP packet to send commands to
the monitor and receive its status.
Community Unit/Group ID Command VMC Command
Format of VMC Packets
A VMC packet is comprised of combinations of strings.
The Category field specifies the category of the
command and the Command field contains the
command string and its parameters. Both fields have
variable length. A space is used as the separator
"Category Command Parameter1 Parameter2"
The termination code (0x00) for the strings is not sent.
The command may not be correctly interpreted if a
space is appended after a string. (You must configure
the receiving device to accept strings with termination
codes or spaces.)
Communication sequence for the VMC
SDCP (TCP) communication sequence
The following diagram shows the SDCP (TCP)
The monitor returns the response to a command upon its
reception. For a command that takes time to process, the
execution continues even after the response is sent out.
If the monitor receives the next command while
executing the previous command, it places the next
command in the queue. For a status request, the monitor
returns the response only after the command result
becomes ready to be sent and the status value is set.
VMC Command Description
Request STATset (1)
Request STATget xxx
Response OK STATret xxx yyy
Request STATset (2)
Request STATset (3)
Refurns its status