Introduction and Terminology

Introduction and Terminology

Art-Osc is designed to provide a standardized syntax for transmission of lighting control data over the Open Sound Control (OSC) protocol. OSC is a transport independent mechanism and, by definition, so is Art-Osc. However it is considered likely that UDP will be the preferred transport. Art-Osc provides a common syntax that allows three separate ‘languages’ to be encapsulated by OSC. These are:

  1. DALI: Transfer of both forward and reverse DALI frames using a per-circuit addressing mechanism with loosely coupled poll and response transactions.
  2. RDM: Transfer of RDM data, in a human readable form, out to devices capable of displaying or acting upon the data.
  3. Automation: Transfer of remote control and triggering information.

Initially, Art-Osc servers are likely to be iPad, iPhone and Android tablet devices.

Glossary of Art-Osc terms and conventions:

  • The abbreviation RDM means: ANSI E1.20 -2010 Entertainment Technology RDM Remote Device Management Over DMX512 Networks.
  • The abbreviation OSC means: The CNMAT, UC Berkeley, Open Sound Control Specification v1.1.
  • The abbreviation DALI means: The IEC 62386 standard.
  • An Art-Osc Client is any device that sends Art-Osc packets.
  • An Art-Osc Server is any device that receives Art-Osc packets.
  • Floating point data is formatted as single precision to the IEEE 754 standard.
  • All multi-byte data is transmitted in big-endian format.
  • Server Port: All Art-Osc servers listen on Port 7000
  • Client Port: All Art-Osc clients send on Port 8000
  • Address Pattern: The first section of an OSC message containing the Signature, Language, Object Vector, Instance and Parameter, all separated by forward slash characters.
  • Signature: A component of the Address Pattern that defines the OSC data as being Art-Osc. It contains the upper case characters ‘AL’.
  • Language: A component of the Address pattern that defines the language of the Art-Osc packet as either DALI, RDM or Automation.
  • Object Vector: A component of the Address pattern, the meaning of which depends upon the Language.
  • Instance: A component of the Address pattern, the meaning of which depends upon the Language.
  • Parameter: A component of the Address pattern, the meaning of which depends upon the Language.
  • Type Tag: A character that denotes the type of the data in the argument list. Example: ‘f’ means floating point.
  • Type Tag String: A string of Tag Type characters that starts with the comma character. Each Tag Type character defines the type of each consecutive argument in the argument list.
  • Argument List: A contiguous sequence of data ordered and formatted as defined by the Tag Type String