Cisco Systems 1080P12X Manual De Usuario

Cisco TelePresence PrecisionHD Camera

PrecisionHD Camera User guide

D14640.09 PrecisionHD 1080p-720p Camera User Guide, June 2012.

www.cisco.com

The VISCA™/RS–232

control protocol

The codec is using the Sony Visa protocol to

control the cameras.

Interfacing the camera
When interfacing to the camera the codec

uses an RS-232 control interface that

resembles the Sony VISCA™ protocol.

Supported cameras
The following Cisco PrecisionHD cameras are

supported:

•

PrecisionHD 1080p12x

•

PrecisionHD 1080p4x

•

PrecisionHD 1080p4xS2

Currently there is support for detection of the

following third party cameras:

•

Sony HD1

•

Sony HD7

VISCA message format

A particular command is recognized by the

message information after the address byte.

Message Format
Commands are initiated from the host (i.e. the

codec or any other external controller) to the

camera.
After a camera has been issued a command,

the camera will generate a response.

Commands and responses (messages) have

the following format:

•

Address byte (1)

•

Message bytes (1..14)

•

Terminator byte (1)

See the illustration for details.

The minimum length of any command or response is 3 bytes:

1. Address byte (1):

Let us assume there is one host, i.e. the codec (the host is the unit

controlling the camera). The host has address 0. The four least significant bits of the address

byte contain the address of the receiver. In the case of a broadcast message, the receiver

address must be set to 8. When we are operating a single camera, the address is 1. Hence,

address bytes in messages from the host are 0x81, and messages from the camera to the

host are 0x90 (the protocol allows for up to 7 cameras).

2. Message bytes (1..14):

Any number of bytes containing the actual message information. Bytes

may have any value in the range 0...254. The value 255 (i.e. hexadecimal FF) is reserved for

the terminating byte.

3. Terminator byte (1):

All messages must be terminated with a byte containing all 1’s, i.e.

decimal 255 (or hexadecimal FF).

Command and response exchange
When the camera receives a command, it

responds with either:

•

Completion message: 90-5Y-FF

Returned by camera when execution of

commands and inquiries are completed.

•

Error packets: 90-6Y-..-FF

Returned by camera instead of a

completion message when command or

inquiry failed to be executed.

•

General error messages, unless otherwise

specified:

•

90-6Y-01-FF Message length error

(>14 bytes)

•

90-6Y-02-FF Syntax error

•

90-6Y-03-FF Command buffer full

•

90-6Y-04-FF Command cancelled

•

90-6Y-05-FF No socket (to be

cancelled)

•

90-6Y-41-FF Command not executable

•

Y = socket number

A camera may contain two buffers so that

two commands, including the command

being executed, can be received.

NOTE:

The PrecisionHD 1080p

camera supports a single socket only.

Consequently, the Y always assumes the

value

Y = 0

Exceptions to these rules:

•

An Initialize message will respond as

indicated in the Table of Commands (this

message is in fact a broadcast message,

and any unit other than the host receiving

the broadcast message must pass it on).

•

Do not route commands or replies that

are longer than 16 bytes through Sony

cameras. The easiest way to avoid this is

to put the Cisco cameras first in the chain.

Commands and replies that are longer than

16 bytes are clearly marked below.

The RS232 Message format

...

Sender’s

address

Receiver’s

address

1 0

LSB

Packet (3 to 16 bytes)

Message (1 to 14 bytes)

Address

Byte 1 Byte 2 Byte 3

Terminator

1 1 1 1 1 1 1 1

LSB

Contents

Appendices

Introduction

The physical interface

Connecting the camera

Video output formats

Daisy chaning

Appendices