IEEE 1355 - Definition

Definition

This description is a brief outline. The standard defines more details, such as the connector dimensions, noise margins, and attenuation budgets.

IEEE 1355 is defined in layers and slices. The layers are network features that are similar in different media and signal codings. Slices identify a vertical slice of compatible layers. The lowest layer defines signals. The highest defines packets. Combinations of packets, the application or transaction layer, are outside the standard.

A slice, an interoperable implementation, is defined by a convenient descriptive code, SC-TM-dd, where:

• SC is the signal coding system. Valid values are DS (data strobe encoding), TS (three of six), and HS (high speed).
• TM is the transmission medium. Valid values are SE (single-ended electrical), DE (differential electrical), and FO (fiber optic)
• dd is the speed in hundreds of megabaud. Note that a baud is a change of the signal, not a bit. Transmission codings may send several bits per baud, or several baud per bit.

Defined slices include:

• DS-SE-02, cheap, useful inside electronic equipment, (200 Mbit/s, <1 meter maximum length).
• DS-DE-02, noise-resistant electrical connections between equipment (200 Mbit/s, <10 meters).
• TS-FO-02, good, useful for long distance connections (200 Mbit/s, <300 meters).
• HS-SE-10, short very fast connections between equipment (1 Gbit/s, <8 meters).
• HS-FO-10, long very fast connections (1 Gbit/s, <3000 meters).

Spacewire is very similar to DS-DE-02, except it uses a standard 9-pin "D" connector (lower-weight, and available much less expensively), and low voltage differential signaling. It also defines some higher-level standard message formats, routing methods, and connector and wire materials that work reliably in vacuum and severe vibration.