Cisco Video Switch, User Manual

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Communicating with the Video Switch
VISCA Standard Commands
Command Set Command
Packet
Comments
CAM_IF_Clear 8x 01 00 01 ff Clear command buffer. Stop any
current operation in progress.
CAM_Address_Set 8x 30 0p ff p = address for this device. If x=8
(broadcast), increase p with 1 before
sending to chain.
CAM_Command_
Cancel
8x 2p ff p = Socket ID. Not supported in TVS
CAM_Power 8x 01 04 00
0p ff
p = 2: Power on. p = 3: Power off.
VISCA Standard Inquiries
Command Command
Packet
Comments
IF_DeviceType_Inq 8x 09 00 02 ff y0 50 gg gg hh hh jj jj kk ff
gggg = Vendor ID
hhhh = Model ID
jjjj = ROM Revision
kk = Max sockets
(No support for this in the TANDBERG
Video Switch. Ignore it.)
CAM_Power_Inq 8x 09 04 00 ff y0 50 0p ff
p = 2: Power on.
p = 3: Power off.
Communicating using VISCA
NOTE! This section applies only to users wanting to
control the switch directly from an external control
system connected to Data port 3 on the switch.
The following describes how to communicate with
the Video Switch using the VISCA protocol.
VISCA Interface Basics
The Video Switch (TVS) uses a RS-232 control
interface that resembles the Sony VISCA protocol.
TVS is configured in exactly the same way as a
VISCA camera. TVS will always be located first in
the camera chain(s).
The main jobs of the VISCA interface in the TVS
are:
•
Select which video source to use
•
Route VISCA messages to the connected
cameras
•
Control picture resolutions sent to the codec
Cameras chained to the switch will start with id 2.
The codec will automatically recognize this and
map the cameras accordingly.
VISCA Serial Ports
The switch has a total of 4 serial ports that
communicate using the VISCA protocol.
•
Port 0, on the THSI interface, is always
connected to the codec.
•
Port 1 is the primary VISCA chain for cameras
connected to the Switch.
•
Port 2 is the secondary VISCA chain for the
cameras that normally are connected to codec
video inputs 2-5. See the section on Enhanced
VISCA below.
•
Port 3 is intended for external control systems,
and works in the same way as port 0, but with
some limitations on available commands. It is
comparable to running the daisy port on a Cisco
TelePresence PrecisionHD 720p camera in
dual-visca mode.
This article covers the use of port 3 as the
control port for the switch. You may use port 0 if
you do not intend to use the THSI interface, but
only use HDMI out.
Enhanced VISCA
Since the switch has two possible camera chains,
all normally formatted commands will be sent to
the primary chain. To access the secondary chain,
you must first turn Enhanced VISCA on with the
SW_eVisca command.
Commands going to the secondary chain must be
prefixed with FE 01. Replies from the secondary
chain will also be prefixed with FE 01. You will only
receive push messages from the secondary chain
if Enhanced VISCA is turned on.
IMPORTANT : Since the switch can receive VISCA
from either the codec or an external control
system, and since there are two possible camera
chains, there are limitations on how commands are
issued and answered:
•
Only one command can be processed at a time
•
Sending a new command when you receive an
ACK from a Sony camera is not allowed. ACK
messages will be thrown away by the switch
•
Reply will always go to the source that issued
the command.
•
Sony push messages will be sent to both
sources.
If this is not expected behaviour, an external control
system may, of course, be setw to control all
connected cameras directly via VISCA.
VISCA Messages
Commands that are prefixed with SW_ are new for
the switch. The CAM_ prefix is used for commands
that are copied from Cisco TelePresence
PrecisionHD 720p camera, or are standard VISCA
messages.
14
Video Switch User guide
D14794.02 Video Switch User Guide, October 2012
© 2011-2012 Cisco Systems, Inc. All rights reserved.
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