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Nuclear |
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> The Bridge choice for VME bus control |
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The VME BUS has its roots in the Motorola 68000 microprocessor data bus architecture: in the past years the VME controllers were nothing more than Motorola 68000-based SBCs (Single Board Computers). The PC increasing popularity turned into the success of the PCI architecture, which allowed the availability of high performance/low cost chipsets, useful for the development of PCI-based motherboards. This fact was so attractive for both industry and scientific research manufacturers, that today is more than unlikely to buy a SBC other than PCI based.
This evolution allowed also the VME controllers to be integrated in the PCI architecture; actually the PCI bus did not replace the VME bus: quite simply today most VME controllers are SBC (based either on Intel or on Motorola processors) featuring PCI architecture and housing one chip which interfaces the PCI bus with the VME bus. Such chips are known as “bridges”.
The innovation in electronics is frequently market-driven: the use of easily available components derived from other fields permits to reduce production costs. Anyway the use of SBCs as VME controllers is not always the smartest (nor the cheapest) solution, since a new type of VME controllers was introduced: the remote bridges (also known as bus interfaces”).
The remote bridge is an evolution of the PCI-based SBC where the PCI to VME interface is split: the VME card hosts the VME part while the PCI interface is placed remotely. In this way it is possible to use the CPU RAM and disks of the remote PC and access the VME cards through a link (USB, optical, firewire, LVDS, etc… ).
This solution is smarter than the SBC use under many points of view, such as lower total cost of ownership, easier hardware and software upgrade, lower CPU usage, development speed up and time-to-market reduction, simplified inter-crate communication, greater realiability.
The new VME crate controllers (Mod. V1718 and V2718) introduced by CAEN SpA feature all such advantages by using two type of links, whose preference depends on the use conditions. The modules are VME64X standard compliant; moreover some additional features and a programmable I/O section make them particularly useful for test and debug purposes.
The CAEN Mod. V1718 is a VME bridge, which uses the USB2.0 as link between the PC and the VME bus: this makes it a particularly user friendly and versatile tool. The module is, in fact, “Plug-and-Play” and allows to control the VME bus also via a notebook; this feature makes the V1718 ideal for either small laboratories or maintenance technicians, where the latter can use it as their portable reference set up. The high data throughput of the USB 2.0 (theoretical: 480 Mbit/s; actual: 30 Mbytes/s) allows most customers to be satisfied with high speed data acquisition using the V1718.
The CAEN Mod. V2718 is a VME bridge, which uses the 1.25 GHz optical link: the smartest solution when the highest data throughput, the lowest latency or greater distances between PC and VME crates must be achieved.CAEN Mod. V2718 has also the capability to control up to 8 VME crates using a single optical link in daisy-chain connection mode so you need only a single PCI card (CAEN Mod. A2818) to control the crates. This unique feature permits a great density because you can host more A2818 PCI cards in a single PC.Moreover the distance achievable (up to 500 m) makes V2718 the better choice when the VME crate is located in a hostile area, where the presence of microprocessors, mass-storage units or other sensible parts is not advisable. Examples of such an environment are the experiments at the CERN LHC, where the superconducting magnets generate high magnetic fields, also where the data acquisition electronics is placed. In this case, the use of the V2718, whose internal electronics tolerate such magnetic fields, is a smart solution, allowing the placement of powerful post-processing workstations at a safe distance from the magnetic field source.
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> EURITRACK project: non-destructive detection and characterisation |
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of illicit substances in containers |
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 The aim of the 3-year, 6 FP priority, STREP EURITRACK project (European Illicit Trafficking Countermeasures Kit), which was launched on 28 and 29 October 2004 at Saclay CEA, is to develop a system for quick and non-destructive detection and analysis of explosives or other dangerous substances hidden in cargo containers. The project involves coupling a neutron detection system with information processing to the existing resources, to analyse the chemical composition of suspect containers, identified by X-ray radiography. By allowing fast and complete analysis of the chemical elements detected inside the container, EURITRACK will provide large sea-ports with a high-performance tool which will reduce the number of manual inspections involving unloading, thereby reducing operational costs, saving time and increasing safety. Coordinated by CEA-LIST, EURITRACK is a consortium of 10 industrial partners and research organizations, representing 5 European countries; CAEN was designed as the manufacturer of the data acquisition electronics and of the detector power supplies. The front end electronics provided for the data acquisition will include both CAEN catalog and custom designed VME boards, while the power supply solution will be SY1527-based.
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Aerospace |
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> Central Payload Power Supply for space applications |
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 The “state of the art” performances of the first Central Payload Power Supply (CPPS) Engineering Model have been illustrated at ESA/ESTEC on 19 January during Power R&D Final Presentation day.
In the case of small satellites, the use of centralised services is usually identified as a potential mass saver. Due to the common need of power conditioning for each Payload, the concept of a Centralised Power Supply may be conceived as a step towards compactness. For this purpose, a Central Payload Power Supply (CPPS) has been specifically designed to power Highly Integrated Payload Suites on future small satellites missions where reduced mass, size and power consumption are key factors.
The CPPS architecture is based on a fully redundant, push-pull, Peak Current Mode control, DC/AC Primary Conversion Stage with symmetrical High Frequency AC Bus. The High Frequency AC Bus (from Main or Redundant DC/AC Primary Conversion Stage) is distributed to 23 Secondary Side Post Regulators (SSPRs) through DPDT latching relays, which perform the instrument ON/OFF management. Each outlet is regulated by means of a step-down, Voltage Mode control, SSPR. A TM interface provides the bus current monitor and the ON/OFF status of each group of Instrument supply voltages.
The CPPS sets a new standard of performances, substantially improving efficiency over currently available state of the art solutions based on ‘off the shelf’, hi-rel converters in the low power range (<5 W).
Thanks to high modularity, compact volume and reduced weight, the CPPS allows to limit the engineering efforts to obtain a wide variety of secondary supply voltages and may be easily adapted to different space missions interface requirements.
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