Digital Signal Interface

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Digital Signal Interface (DSI) is a protocol for dimming stage lighting (initially electrical ballasts). It was created in 1991 by Austrian company Tridonic ATCO and is based on Manchester-coded 8-bit protocol, data rate of 1200 baud, 1 start bit, 8 data bits (dimming value), 4 stop bits, and is the basis of the more sophisticated protocol Digital Addressable Lighting Interface (DALI).

The technology uses a single byte to communicate the lighting level ( 0-255 or 0x00-0xFF). DSI was the start of digital communication technology and was the precursor to DALI.

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[edit] Advantages

  • Its simple nature makes it straightforward to understand, implement, and diagnose, while its low voltage means it typically runs along relatively thin cables.
  • Because each device has its own wire to the controller (rather than being part of a network) it has no need of an address to be set, so can be replaced simply by unplugging the faulty one and plugging in the new.

[edit] Disadvantages

  • It requires one wire per control channel so a sophisticated system could have hundreds of wires, thereby making diagnoses of problems difficult.

[edit] Rival protocols


[edit] DALI

DALI is an open standard for digital control of lighting. Several companies have adopted the DALI protocol in their product offerings. Even though DALI is an open standard, there are already versions of its implementation emerging in different lighting manufacturers products as they strive to provide a point of difference. DSI is essentially the same technology as DALI in terms of messaging, however, DSI eliminates the individual addressing aspect of each light fitting found in DALI.