FASTBUS

Last updated

FASTBUS (IEEE 960) is a computer bus standard, originally intended to replace Computer Automated Measurement and Control (CAMAC) in high-speed, large-scale data acquisition. It is also a modular crate electronics standard commonly used in data acquisition systems in particle detectors.

Computer Automated Measurement and Control

Computer-Aided Measurement And Control (CAMAC) is a standard bus and modular-crate electronics standard for data acquisition and control used in particle detectors for nuclear and particle physics and in industry. The bus allows data exchange between plug-in modules and a crate controller, which then interfaces to a PC or to a VME-CAMAC interface.

Modular crate electronics are a general type of electronics and support infrastructure commonly used for trigger electronics and data acquisition in particle detectors. These types of electronics are common in such detectors because all the electronic pathways are made by discrete physical cables connecting together logic blocks on the fronts of modules. This allows circuits to be designed, built, tested, and deployed very quickly as an experiment is being put together. Then the modules can all be removed and used again when the experiment is done.

In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator. Detectors can measure the particle energy and other attributes such as momentum, spin, charge, particle type, in addition to merely registering the presence of the particle.

Contents

Bus description

A FASTBUS system consists of one or more segments. Each segment may be a "crate segment" or a "cable segment". Segments are connected together using a segment interconnect (SI). A crate segment typically consists of a backplane with slots to hold up to 26 modules, mounted in a 19-inch rack. Each module is typically a printed circuit board with a front panel, similar to a blade PC. Modules are physically about 14 inches by 15 inches, and may occupy one or more adjacent slots. [1]

19-inch rack standardized frame or enclosure for mounting multiple equipment modules

A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is 19 inches (48.3 cm) wide. The 19-inch dimension includes the edges, or "ears", that protrude on each side which allow the module to be fastened to the rack frame with screws. Common uses include computer server, telecom, broadcast video, lighting, audio, and scientific lab equipment.

A blade PC is a form of client or personal computer (PC). In conjunction with a client access device on a user's desk, the supporting blade PC is typically housed in a rack enclosure, usually in a datacenter or specialised environment. Together, they accomplish many of the same functions of a traditional PC, but they also take advantage of many of the architectural achievements pioneered by blade servers.

Small systems may consist of only one crate segment, or a small number of independent crate segments connected directly to a central computer rather than using segment interconnects.

FASTBUS uses the emitter coupled logic (ECL) electrical standard, which allows higher speed than TTL and generates less switching noise. Segments implement a 32-bit multiplexed address/data bus, which allows a larger address space than CAMAC. A module may be a master or slave. There may be multiple masters in a segment; masters arbitrate for control of the bus and then perform data transfers to or from slaves. This allows for very fast read-out of an entire segment by doing a chained block read from a master with a general-purpose CPU. Each I/O card will then assume mastership, send its data and then hand off mastership to the next card in a sequence, all without the overhead of the supervising board with the general-purpose CPU.

Cable Segments are implemented using 32-bit-wide parallel twisted-pair cables and a differential signalling scheme. The electrical standard allows regular ECL receiver chips but requires custom transmitter circuits which allow lines to be safely driven both high and low at the same time - this feature is required by the arbitration logic.

Full-size crates hold 26 modules. [1] Each module may dissipate up to 70 W, giving a total crate heat load of 1750 W. Modules require a −5.2 V supply for the ECL interface, usually a separate −2 V supply for ECL termination, and often a +5 V supply for TTL or CMOS logic. The FASTBUS standard also has +15 V and -15 V pins on the backplane, which are typically fed with very small power supplies as most modules use very little +/- 15 V (or any at all). Special high-capacity power supplies with large 15 V supplies would have to be used if modules drew large amounts of current on those rails. Crates typically have dedicated 200 A or 300 A switched-mode power supplies, providing current to the modules through multiple pins on the backplane connector. A large installation typically has multiple racks, each with three crates. Cooling and air handling are a significant issue, as is the safe design of high-current power distribution.

Physical description

A FASTBUS crate is quite a bit taller than other types of electronics crates. The power supply for a FASTBUS crate is typically mounted below the crate, rather than being integral for the crate itself, taking up even more vertical rack space.

History

FASTBUS was conceived as a replacement for CAMAC in data acquisition systems. Limitations of CAMAC were a slow bus speed, limited bus width, single bus controller and unwieldy inter-crate communications (the CAMAC Branch Highway). FASTBUS sought improvement in all these areas by using a faster bus logic (ECL), an asynchronous bus protocol, and a sophisticated multi-segment design. At the time, it seemed obvious that the way to get higher speed was a wide parallel bus, since the logic for each bit was already as fast as the electronics allowed. Later developments have moved to high-speed serial protocols such as SATA, leaving designs such as the FASTBUS serial segment as a technological dead end.

The IEEE standard was originally approved in May 1984.

FASTBUS was used in many high-energy physics experiments during the 1980s, principally at laboratories involved in the development of the standard. These include CERN, SLAC, Fermilab, Brookhaven National Laboratory, and TRIUMF.

CERN International organization which operates the worlds largest particle physics laboratory

The European Organization for Nuclear Research, known as CERN, is a European research organization that operates the largest particle physics laboratory in the world. Established in 1954, the organization is based in a northwest suburb of Geneva on the Franco–Swiss border and has 23 member states. Israel is the only non-European country granted full membership. CERN is an official United Nations Observer.

Fermilab laboratory in Illinois, USA

Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been operated by the Fermi Research Alliance, a joint venture of the University of Chicago, and the Universities Research Association (URA). Fermilab is a part of the Illinois Technology and Research Corridor.

Brookhaven National Laboratory United States Department of Energy national laboratory

Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, New York, on Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base. Its name stems from its location within the Town of Brookhaven, approximately 60 miles east of New York City.

FASTBUS has now largely been replaced by VMEbus in smaller-scale systems and by custom designs (which have lower per-channel cost) in large systems.

VMEbus

VMEbus is a computer bus standard, originally developed for the Motorola 68000 line of CPUs, but later widely used for many applications and standardized by the IEC as ANSI/IEEE 1014-1987. It is physically based on Eurocard sizes, mechanicals and connectors, but uses its own signalling system, which Eurocard does not define. It was first developed in 1981 and continues to see widespread use today.

The problems of manufacturing cable segment transmitter chips reliably, together with the cable-handling issues of the wide parallel bus, contributed to the low usage of cable segments. The system interconnect modules were also complex and expensive, again discouraging cable segment use. These problems, together with the late development of inexpensive protocol chips, hindered the expression of the full potential of FASTBUS multi-segment architecture.

Standards

FASTBUS is described in the IEEE standard 960-1986: "IEEE Standard FASTBUS Modular High-Speed Data Acquisition and Control System"

The system on which the IEEE standard is based (US Department of Energy Report DOE/ER-0189) was developed by the NIM committee of the US Department of Energy. Representatives of the ESONE committee of European laboratories and of other laboratories in Europe and Canada also contributed to the standard.

Related Research Articles

Backplane

A backplane is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete computer system. Backplanes commonly use a printed circuit board, but wire-wrapped backplanes have also been used in minicomputers and high-reliability applications.

Expansion card a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer motherboard, backplane or riser card to add functionality to a computer system via the expansion bus

In computing, the expansion card, expansion board, adapter card or accessory card is a printed circuit board that can be inserted into an electrical connector, or expansion slot, on a computer motherboard, backplane or riser card to add functionality to a computer system via the expansion bus.

Scalable Coherent Interface organization

The Scalable Coherent Interface or Scalable Coherent Interconnect (SCI), is a high-speed interconnect standard for shared memory multiprocessing and message passing. The goal was to scale well, provide system-wide memory coherence and a simple interface; i.e. a standard to replace existing buses in multiprocessor systems with one with no inherent scalability and performance limitations.

Futurebus, or 'IEEE 896, is a computer bus standard, intended to replace all local bus connections in a computer, including the CPU, memory, plug-in cards and even, to some extent, LAN links between machines. The effort started in 1979 and didn't complete until 1987, and then immediately went into a redesign that lasted until 1994. By this point, implementation of a chip-set based on the standard lacked industry leadership. It has seen little real-world use, although custom implementations continue to be designed and used throughout industry.

Low-voltage differential signaling technical standard

Low-voltage differential signaling, or LVDS, also known as TIA/EIA-644, is a technical standard that specifies electrical characteristics of a differential, serial communications protocol. LVDS operates at low power and can run at very high speeds using inexpensive twisted-pair copper cables. LVDS is a physical layer specification only; many data communication standards and applications use it and add a data link layer as defined in the OSI model on top of it.

Data acquisition all methods of simultaneous or sequential time measurement and counting for measurable or quantifiable data and groups of contiguous data

Data acquisition is the process of sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems, abbreviated by the acronyms DAS or DAQ, typically convert analog waveforms into digital values for processing. The components of data acquisition systems include:

A Controller Area Network is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. It is a message-based protocol, designed originally for multiplex electrical wiring within automobiles to save on copper, but is also used in many other contexts.

Electronic test equipment equipment used to create signals and capture responses from electronic devices under test

Electronic test equipment is used to create signals and capture responses from electronic devices under test (DUTs). In this way, the proper operation of the DUT can be proven or faults in the device can be traced. Use of electronic test equipment is essential to any serious work on electronics systems.

The Serial Peripheral Interface (SPI) is a synchronous serial communication interface specification used for short-distance communication, primarily in embedded systems. The interface was developed by Motorola in the mid-1980s and has become a de facto standard. Typical applications include Secure Digital cards and liquid crystal displays.

Advanced Telecommunications Computing Architecture is the largest specification effort in the history of the PCI Industrial Computer Manufacturers Group (PICMG), with more than 100 companies participating. Known as AdvancedTCA, the official specification designation PICMG 3.x was ratified by the PICMG organization in December 2002. AdvancedTCA is targeted primarily to requirements for "carrier grade" communications equipment, but has recently expanded its reach into more ruggedized applications geared toward the military/aerospace industries as well. This series of specifications incorporates the latest trends in high speed interconnect technologies, next-generation processors, and improved Reliability, Availability and Serviceability (RAS).

The Nuclear Instrumentation Module (NIM) standard defines mechanical and electrical specifications for electronics modules used in experimental particle and nuclear physics. The concept of modules in electronic systems offers enormous advantages in flexibility, interchange of instruments, reduced design effort, ease in updating and maintaining the instruments.

STEbus

The STEbus is a non-proprietary, processor-independent, computer bus with 8 data lines and 20 address lines. It was popular for industrial control systems in the late 1980s and early 1990s before the ubiquitous IBM PC dominated this market.

Parallel SCSI

Parallel SCSI is the earliest of the interface implementations in the SCSI family. SPI is a parallel data bus; There is one set of electrical connections stretching from one end of the SCSI bus to the other. A SCSI device attaches to the bus but does not interrupt it. Both ends of the bus must be terminated.

A CPU card is a printed circuit board (PCB) that contains the central processing unit (CPU) of a computer. CPU cards are specified by CPU clock frequency and bus type as well as other features and applications built into the card.

Fbus is an ANSI/IEEE data bus protocol oriented towards backplanes and cell phones. The standard specifies a way for various pieces of electronic hardware to communicate, typically with one piece acting as master, and another acting as a slave. The F-Bus is a bi-directional full-duplex serial type bus running at 115,200 bit/s, 8 data bits, no parity, one stop bit (8N1). Much like a standard RS-232 serial port, F-Bus connections use one pin for data transmit, one pin for data receive and one pin for ground.

VAX 8000

The VAX 8000 is a discontinued family of minicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA).

HP BladeSystem blade server

BladeSystem is a line of blade server machines from Hewlett Packard Enterprise that was introduced in October 2004.

References

  1. 1 2 "AN INTRODUCTION TO FASTBUS". FNAL. Archived from the original on 23 September 2013. Retrieved 21 September 2013.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.