VISCA Protocol

From Wikipedia, the free encyclopedia

VISCA is a professional camera control protocol used with PTZ cameras. It was designed by Sony to be used on several of its surveillance and OEM block cameras.

Implementation

It is based on RS232 Serial communications at 9600 bit/s, 8N1, no flow control typically though a DB9 connector, but can also be on 8-Pin DIN, RJ45 and RJ11 connectors use in daisy chain configurations.

VISCA utilizes a serial repeater network configuration to communicate between the PC (device #0) and up to 7 peripherals (#1 through #7). The daisy chain cable configuration means that a message walks the chain until it reaches the target device identified in the data packet. Responses then walk the rest of the way down the chain and back up again to reach the system. Some packets may be broadcast to all devices.

A command data packet consists:

Address byte (1) message header
Information bytes (1..14)
Terminating byte (1) 0xFF

The message header is of the format:

bit 7: always ‘1’
bits 6-4: source device#
bit 3: ‘0’ normal packet/ ‘1’ for broadcast packets
bits 2-0: destination device# or ‘000’ for broadcast
In the packet descriptions below, multi-byte quantities are big-endian (Motorola-style) ordering, with the MSB at
[i] and the LSB at [i+1].

Each command data packet has a corresponding response data packet. The response to a particular packet is variable in size and may indicate an error condition.

Uses

The VISCA Protocol is used on Polycom and Cisco/Tandberg video conferencing systems. Sony and Canon use VISCA for CCTV cameras.

External links

This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.