Communicating with the video switch – TANDBERG RJ45RJ11 User Manual

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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.

VISCA Standard Push Messages

Command

Command Packet

Comments

CAM_Network_Change

x0 38 ff

This indicates that cameras have been

added to or removed from the camera

chain.

To avoid issues with (some) Sony

cameras, the control system or

codec should delay 9 seconds before

reconfiguring the chain.

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 TANDBERG Video Switch using the

VISCA protocol. For details about the protocol

implementation, refer to the System Integrators

Guide – Interfacing to the TANDBERG Wave 2

Camera.

VISCA Interface Basics

The TANDBERG 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

TANDBERG Precision HD Camera in dualvisca

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 TANDBERG Precision HD

Camera, or are standard VISCA messages.

Communicating with the Video Switch

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