S-LINK
Encyclopedia
S-LINK, for simple link interface, is a high-performance data acquisition standard developed at CERN
for collecting information from particle accelerator
s and other sources. Unlike similar systems, S-LINK is based on the idea that data will be collected and stored by computers at both ends of the link, as opposed to a "dumb" devices collecting data to be stored on a "smart" computer. Having a full computer at both ends allows S-LINK to be very thin, primarily defining the logical standards used to feed data at high speed from the motherboards to the link hardware interfaces.
S-LINK started in 1995 in response to problems collecting data from the new ATLAS experiment
at CERN. ATLAS was extensively instrumented with stand-alone computers, which sent data via a variety of methods to be collected on various servers. S-LINK was seen as a way to provide a single mechanism for forwarding the data from the collection to the link hardware with extremely low latency. Generally the S-LINK hardware provided functionality that would normally be provided by networking (or other) drivers running on the host CPU
, thereby tying up cycles and introducing delays.
S-LINK used a 32-bit
bus running up to 66 MHz, allowing for throughout up to 264 MB
/s. The "link side" was typically connected to optical fibre for transmission to the collecting machines, known as the read-out motherboard, or ROMB. Data could also be sent back to the front-end motherboard or FEMB, typically for flow control purposes at a much lower speed.
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
for collecting information from particle accelerator
Particle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
s and other sources. Unlike similar systems, S-LINK is based on the idea that data will be collected and stored by computers at both ends of the link, as opposed to a "dumb" devices collecting data to be stored on a "smart" computer. Having a full computer at both ends allows S-LINK to be very thin, primarily defining the logical standards used to feed data at high speed from the motherboards to the link hardware interfaces.
S-LINK started in 1995 in response to problems collecting data from the new ATLAS experiment
ATLAS experiment
ATLAS is one of the six particle detector experiments constructed at the Large Hadron Collider , a new particle accelerator at the European Organization for Nuclear Research in Switzerland...
at CERN. ATLAS was extensively instrumented with stand-alone computers, which sent data via a variety of methods to be collected on various servers. S-LINK was seen as a way to provide a single mechanism for forwarding the data from the collection to the link hardware with extremely low latency. Generally the S-LINK hardware provided functionality that would normally be provided by networking (or other) drivers running on the host CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
, thereby tying up cycles and introducing delays.
S-LINK used a 32-bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
bus running up to 66 MHz, allowing for throughout up to 264 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
/s. The "link side" was typically connected to optical fibre for transmission to the collecting machines, known as the read-out motherboard, or ROMB. Data could also be sent back to the front-end motherboard or FEMB, typically for flow control purposes at a much lower speed.