IEEE 1355

IEC 14575 is a low-cost, low latency, scalable serial interconnection system, originally intended for communication between large numbers of inexpensive computers.

The standard defined several different types of transmission media (including wires and optic fiber), to address different applications.

The protocol was designed for a simple, low cost switched network made of point-to-point links.

This network sends variable length data packets reliably at high speed.

Unlike Token Ring or other types of local area networks (LANs) with comparable specifications, IEEE 1355 scales beyond a thousand nodes without requiring higher transmission speeds.

IEEE 1355 had goals like Futurebus and its derivatives Scalable Coherent Interface (SCI), and InfiniBand.

][citation needed], and gives one hundred times the data transmission capacity, while implementing a full switching network and being easier to program.

IEEE 1355 resulted from an attempt to preserve the Transputer's unusually simple data network.

This data strobe encoding scheme makes the links self-clocking, able to adapt automatically to different speeds.

IEEE 1355 is used in scientific instrumentation because it is easy to program and it manages most events by itself without complex real-time software.

[4] Researchers measuring the performance and reliability of the Macramé testbed provided useful input to the working group which established the standard.

[5] The work of the Institute of Electrical and Electronics Engineers was sponsored by the Bus Architecture Standards Committee as part of the Open Microprocessor Systems Initiative.

The chair of the group was Colin Whitby-Strevens, co-chair was Roland Marbot, and editor was Andrew Cofler.

[7] The family of standards use similar logic and behavior, but operate at a wide range of speeds over several types of media.

This makes it compatible with other common transmission media, including standard telecommunications links.

When there is an error, the two ends of a link exchange an interval of silence or a reset, and then restart the protocol as if from power-up.

Each link defines a full-duplex (continuous bidirectional transmission and reception) point-to-point connection between two communicating pieces of electronics.

In the high speed optical slices, half-duplex throughput would be limited by the synchronization time of the phase locked loops used to recover the bit clock.

The standard defines more details, such as the connector dimensions, noise margins, and attenuation budgets.

A slice, an interoperable implementation, is defined by a convenient descriptive code, SC-TM-dd, where: Defined slices include: Spacewire is very similar to DS-DE-02, except it uses a microminiature 9-pin "D" connector (lower-weight), 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.

Every slice defines a number of special link control characters, sometimes called "L-chars."

Building flow control in at a low level makes the link far more reliable, and removes much of the need to retransmit packets.

Hardware does not need to store the packet, or perform any other calculations on it in order to copy it and route it.

It sends data at up to 200 megabits per second, for up to 1 meter, this is useful inside an instrument for reliable low-pin-count communications.

Note the implementation the "half twist", routing inputs and outputs to the same pins on each plug.

If it is absent, the pins should include a 1 MΩ resistor to ground to leak away static voltages.

Combined with a longitudinal redundancy check, it avoids the need for a CRC which can double the size of small packets.

And when the nibble has two 1 bits, there is ambiguity: HS-SE stands for "High speed, Single-ended Electrical."

However, the modulation and link control features of this standard are also used by the wide-area fiber optic protocols.