PLATO Main Electronics Units (MEU) based on inputs from P. Plasson and the system team J. Miguel Mas-Hesse Centro de Astrobiología (CSIC-INTA)

PLATO Kick Off November 2010J. Miguel Mas-Hesse2 On-board data processing: Introduction Stellar fieldPLATO image DPS goal: automatically process and extract accurate stellar light curves from the raw, messy CCD images.

PLATO Kick Off November 2010J. Miguel Mas-Hesse3 On-board data processing: baseline concept The normal-telescopes onboard data processing system will be formed by: –4 CCD + 1 FEE per focal plane (telescope) 32 telescopes –1 Data Processing Unit (DPU) per 2 focal planes 16 DPU boards –4 DPUs per 1 Main Electronics Unit (MEU) 4 MEU boxes –1 Instrument Control Unit (ICU) per 4 MEUs 1 ICU (+ 1 fully redundant ICU)

PLATO Kick Off November 2010J. Miguel Mas-Hesse4 On-board data processing: architecture 1 N-DPU for 2 N-cameras F-cameras

PLATO Kick Off November 2010J. Miguel Mas-Hesse5 On-board data processing: architecture Present MEU baseline concept: + 1 DPU per 2 focal planes + 1 single DPU PSU box, external to the MEU’s To ICU-MTo ICU-R SpW

PLATO Kick Off November 2010J. Miguel Mas-Hesse6 PLATO MEU: FEE – DPU SpW link FEE – DPU link baseline: –2 SpaceWire links per FEE (100 Mbps) Alternative: –1 SpaceWire link per FEE (200 Mbps) Feasibility has to be demonstrated. SpW 100 Mbps

PLATO Kick Off November 2010J. Miguel Mas-Hesse7 On-board data processing: architecture

PLATO Kick Off November 2010J. Miguel Mas-Hesse8 On-board data processing: architecture

PLATO Kick Off November 2010J. Miguel Mas-Hesse9 PLATO MEU: operation Window Extraction up to stars / 25 sec Fullimage Acquisition x 8 2 images / 6.25 sec Data correction and LC extraction Masks & window positions updating 6.25 sec 6.25 sec 6.25 sec 5400 sec Target count for 2 x 4 CCD per DPU (to be processed every 25 sec.): Nominal sample 2x( stars/telescope) = stars/DPU Extended sample (+50% margin) = stars/DPU Background win.2 x 400 Imagettes up to 2 x Offset windows2 x 2 x 4 half-row (2.255 pixels) Smearing rows 2 x 4 x 10 overscan rows Total memory requirement, including 50% margin on star count: 250 Mbytes per DPU

PLATO Kick Off November 2010J. Miguel Mas-Hesse10 PLATO MEU: CPU load The CPU load has been estimated for various processors, based on current baseline for number of stars + extraction algorithms. At this phase the %CPU load should be ≤ 50%. The present concept seems feasible, but: –with 1 DPU/2 telescopes, no margin on star counts acceptable. –with 1 DPU/telescope an extended sample with +50% margin in star counts could be considered, if required.. Weighted mask photometry assumed

PLATO Kick Off November 2010J. Miguel Mas-Hesse11 PLATO MEU: open points Backup concept: + 1 DPU board per telescope + 4 DPUs per MEU + 8 MEU More powerful, but too heavy

PLATO Kick Off November 2010J. Miguel Mas-Hesse12 PLATO MEU: open points BaselineAlternative Number of telescopes per DPU 21 MEU-PSU1 MEU-PSU box for 4 MEU boxes 4 MEU-PSU inside each MEU box FEE / DPU number of SpaceWire links 2 SpaceWire links per FEE (100 Mbps) 1 SpaceWire links per FEE (200 Mbps) FEE  DPU image transfer mechanism and protocol RMAPDMA transfer tables DPU Boot mechanismBoot Software in PROMPure RMAP hardware boot

PLATO Kick Off November 2010J. Miguel Mas-Hesse13 PLATO: next steps The industrial MEU definition study is starting now. Goals: –Definition and dimensioning of the N-DPUs Global architecture, choice of processors, number of SpaceWire data links, location of PSUs, mass, power comsumption,… Trade off on algorithms potential increase of complexity – Development of simulators/breadboards for critical interfaces Spacewire link FEE – DPU Final design within mass and power budgets, but compliant with scientific requirements!