Software acceleration on Xilinx FPGAs using OmpSs@FPGA ecosystem

The OmpSs@FPGA programming model allows offloading application functionality to Xilinx Field Programmable Gate Arrays (FPGAs). The OmpSs compiler splits the code (written in C/C++ high level language) in two parts, targeting the host and the FPGA. The first is usually compiled by the GNU Compiler Collection (GCC), while the latter is given to the Xilinx Vivado HLS tool (hereafter HLS) for high level synthesis to VHDL and bitstream used to program the FPGA. OmpSs@FPGA is based on compiler directives, which allow the programmer to annotate the part of the code to automatically exploit all Symmetric MultiProcessor system (smp) and FPGA resource available in the execution platform. This technical report provides both descriptive and hands-on introductions to build application-specific FPGA systems using the high-level OmpSs@FPGA tool. The goal is to give the reader a baseline view of the process of creating an optimized hardware design annotating C-based code with HLS directives. We assume the reader has a working knowledge of C/C++, and familiarity with basic computer architecture concepts (e.g. speedup, parallelism, pipelining)

Performance and energy footprint assessment of FPGAs and GPUs on HPC systems using Astrophysics application

New challenges in Astronomy and Astrophysics (AA) are urging the need for a large number of exceptionally computationally intensive simulations. "Exascale" (and beyond) computational facilities are mandatory to address the size of theoretical problems and data coming from the new generation of observational facilities in AA. Currently, the High Performance Computing (HPC) sector is undergoing a profound phase of innovation, in which the primary challenge to the achievement of the "Exascale" is the power-consumption. The goal of this work is to give some insights about performance and energy footprint of contemporary architectures for a real astrophysical application in an HPC context. We use a state-of-the-art N-body application that we re-engineered and optimized to exploit the heterogeneous underlying hardware fully. We quantitatively evaluate the impact of computation on energy consumption when running on four different platforms. Two of them represent the current HPC systems (Intel-based and equipped with NVIDIA GPUs), one is a micro-cluster based on ARM-MPSoC, and one is a "prototype towards Exascale" equipped with ARM-MPSoCs tightly coupled with FPGAs. We investigate the behavior of the different devices where the high-end GPUs excel in terms of time-to-solution while MPSoC-FPGA systems outperform GPUs in power consumption. Our experience reveals that considering FPGAs for computationally intensive application seems very promising, as their performance is improving to meet the requirements of scientific applications. This work can be a reference for future platforms development for astrophysics applications where computationally intensive calculations are required.Comment: 15 pages, 4 figures, 3 tables; Preprint (V2) submitted to MDPI (Special Issue: Energy-Efficient Computing on Parallel Architectures

Evaluating SoC power efficiency through N-body application

Currently, the High Performance Computing (HPC) sector is undergoing a profound phase of innovation, in which the main stopper in order to achieve "exascale" performance is the power-consumption. The usage of "unconventional" low-cost computing systems is therefore of great interest for several scientific communities looking for a better trade-off between performance and power consumption. In this technical report, we make a performance assessment of commodity low-power System on Chip (SoC) using a direct N-body application for astrophysics. We also describe the methodology we have employed to measure the power drained by the application while running. We find that SoC technology could represent a valid alternative to traditional technology for HPC in terms of good trade-off between time-to-solution and energy-to-solution. This work arises in the framework of the ExaNeSt and EuroExa projects, which investigate the design of a SoC-based, low-power HPC architecture with a dedicated interconnection scalable to million of compute units

Industrial solutions trends for the control of HiRes spectrograph@E-ELT

Starting a few years ago, ESO initiated a number of projects aiming to explore the possible adoption of industrial standards and commercial off-the-shelf components (COTS) for the control of future VLT and E-ELT instrumentations. In this context, ESPRESSO, the next generation high-stability spectrograph for the VLT and to a certain extent, a precursor of HiRes, has adopted since the preliminary design phase those solutions. Based on the ESPRESSO experience and taking into account the requirements inferred from the preliminary Hi-Res studies in terms of both high-level operations as well as low-level control, I will present in this paper the current proposal for the HiRes hardware architecture. <P /

ESPRESSO Instrument Control Electronics and Software: final phases before the installation in Chile.

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, is undergoing the final testing phases before being shipped to Chile and installed in the Combined Coudé Laboratory (CCL) at the European Organisation for Astronomical Research in the Southern Hemisphere - Very Large Telescope site (ESO-VLT). The integration of the instrument took place at the Astronomical Observatory of Geneva. It included the full tests of the Instrument Control Electronics (ICE) and Control Software, designed and developed at the INAF - Astronomical Observatory of Trieste. ESPRESSO is the first ESO-VLT permanent instrument whose electronics is based on Beckhoff PLCs. Two PLC CPUs shares all the workload of the ESPRESSO functions and communicates through the OPC-UA protocol with the VLT instrument control software. In this phase all the devices and subsystems of ESPRESSO are installed, connected together and verified, mimicking the final working conditions in Chile. This paper will summarize the features of the ESPRESSO control system, the tests performed during the integration in Europe and the main performances obtained before the integration of the whole instrument “on sky” in South America

A PLC Distributed Layout: the Case of the Instrument Control Electronics of ESPRESSO

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations of the European Southern Observatory (ESO) is passing the integration phase in Geneva before being shipped to Chile and installed at the Very Large Telescope (VLT) site on the Cerro Paranal. It is going to be one of the first permanent instruments of VLT with a distributed control electronics based on Beckhoff PLCs. About 40 motorized stages, more than 90 sensors and several calibration lamps are controlled by the Instrument Control Electronics (ICE) and Software (ICS). All the ESPRESSO functionalities are managed by two main CPUs that Sshare the workload. The Beckhoff EtherCAT decentralization modules ensure the EtherCAT continuity between the 7 PLC electronics subracks placed in different cabinets, allowing optimal distributed architecture. Furthermore, one of the two CPUs is equipped with an IEEE 1588 protocol interface, used for the time synchronization of the distributed clocks in the networks. In this paper the features of the CPUs used, the distribution of functions among them, the electronic cabinets configuration and a detailed overview of the PLC control system used are presented

Integration of the instrument control electronics for the ESPRESSO spectrograph at ESO-VLT

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations of the ESO - Very Large Telescope site, is now in its integration phase. The large number of functions of this complex instrument are fully controlled by a Beckhoff PLC based control electronics architecture. Four small and one large cabinets host the main electronic parts to control all the sensors, motorized stages and other analogue and digital functions of ESPRESSO. The Instrument Control Electronics (ICE) is built following the latest ESO standards and requirements. Two main PLC CPUs are used and are programmed through the TwinCAT Beckhoff dedicated software. The assembly, integration and verification phase of ESPRESSO, due to its distributed nature and different geographical locations of the consortium partners, is quite challenging. After the preliminary assembling and test of the electronic components at the Astronomical Observatory of Trieste and the test of some electronics and software parts at ESO (Garching), the complete system for the control of the four Front End Unit (FEU) arms of ESPRESSO has been fully assembled and tested in Merate (Italy) at the beginning of 2016. After these first tests, the system will be located at the Geneva Observatory (Switzerland) until the Preliminary Acceptance Europe (PAE) and finally shipped to Chile for the commissioning. This paper describes the integration strategy of the ICE workpackage of ESPRESSO, the hardware and software tests that have been performed, with an overall view of the experience gained during these project's phases. <P /

EELT-HIRES the high resolution spectrograph for the E-ELT: software and hardware solutions for its control

The current E-ELT instrumentation plan foresees a High Resolution Spectrograph conventionally indicated as EELTHIRES whose Phase A study has started in March 2016. Since 2013 however, a preliminary study of a modular E-ELT instrument able to provide high-resolution spectroscopy (R 100,000) in a wide wavelength range (0.37-2.5 μm) has been already conducted by an international consortium (termed "HIRES initiative"). Taking into account the requirements inferred from this preliminary work in terms of both high-level operations as well as low-level control, we will present in this paper possible solutions for HIRES hardware and software architecture. The validity of the proposed architectural and hardware choices will be eventually discussed based also on the experience gained on a real-working instrument, ESPRESSO, the next generation high-stability spectrograph for the VLT and to certain extent the precursor of HIRES. <P /

A complete automatization of an educational observatory at INAF-OATs

The Astronomical Observatory of Trieste (OATs), part of the Italian Institute for Astrophysics (INAF), hosts a Celestron C14 telescope, equipped with a robotic Paramount ME equatorial mount, used for public outreach. The telescope is installed inside a dome, recently upgraded with a Beckhoff PLC control system, a SIEMENS inverter for the communication with the motor of the dome's roof, and further equipment to allow the complete automatization of the system. A peculiarity of the system is that, when operating, the telescope may exceed the height of the roof: due to this fact the telescope pointing is constrained by the full opening of the roof and, oppositely, the closing of the roof is allowed only when the telescope is in park position. Appropriate sensors are installed to monitor the position of the telescope to properly handle the complete opening or closing of the roof. Several emergency operations are also foreseen, for example in case of bad weather or lost connection with the user. The PLC software has been developed using TwinCAT software. An OPC-UA server is installed in the PLC and allows the communication with a web interface. The web GUI, developed in PHP and Javascript, allows the user to perform the remote operations like switching on all the instrumentations, open the dome's roof, park the telescope and view the status of the system. Furthermore through TheSkyX software it is possible to perform the pointing of the telescope and its set up. A dedicated script, interfaced with TheSkyX, have been implemented to perform a complete automated acquisition. An appropriate data storage system is foreseen. All these elements, that cooperate to create a fully remoted controlled system, are presented in this paper

The instrument control electronics of the ESPRESSO spectrograph @VLT

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, is a super-stable Optical High Resolution Spectrograph for the Combined Coudé focus of the Very Large Telescope (VLT). It can be operated either as a single telescope instrument or as a multi-telescope facility, by collecting the light of up to four Unit Telescopes (UTs). From the Nasmyth focus of each UT the light is fed, through a set of optical elements (Coudé Train - CT), to the Front End Unit (FEU) which performs several functions, as image and pupil stabilization, inclusion of calibration light and refocusing. The light is then conveyed into the spectrograph fibers. The whole process is handled by several electronically controlled devices. About 40 motorized stages, more than 90 sensors and several calibration lamps are controlled by the Instrument Control Electronics (ICE) and Software (ICS). The technology employed for the control of the ESPRESSO subsystems is PLC-based, with a distributed layout close to the functions to control. This paper illustrates the current status of the ESPRESSO ICE, showing the control architecture, the electrical cabinet’s organization and the experiences gained during the development and assembly phase