Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/irlab/doc/spie_06/6274-33.pdf Дата изменения: Tue Jun 13 19:11:32 2006 Дата индексирования: Sat Dec 22 06:56:13 2007 Кодировка:

The Versatile Acquisition System of Giano
C.Baffa, V.Biliotti, S.Gennari, E.Giani, I.Mochi, E.Oliva, L.Origlia, E.Rossetti, M.Sozzi
INAF-OAA, INAF-OABO, INAF-CGG, INAF-IRA


Giano spectrometer
To be installed at

T h e T NG T he G a l i l e o I t a l i a n N atio n al T e les co p e L a P alm a


Main characteristics


All Near-IR spectrum measured in a single shot High Resolution up to R=46,000 Range=0.9-2.5m Low Resolution R=400 Range=0.9-2.5m Very Low Resolution. R=200 Range=0.7-2.5m









Common users instrument: always at telescope


Giano Detector


2 K x 2 K H aw a i i 2 18 m Pixel Pitch 0 . 7 - 2. 5 m m r a n g e M u l t i p l e M od e s Low Dark Current (<1 e-/sec) Low Read Noise (<10 e-) Q .E . > 6 0 % 3 - 6 m V /eW e l l C a pa c i t y ~ 1 0 5 e L ow G l ow i n g


The acquisition system development guidelines


T he s y s t e m i s d i vi de d i n s e v e r a l m o d u l e s w i t h c l e a r b o u nd a r i e s . We use, as far as possible, commercial parts at board level. We use largely accepted standards as boundaries, as a PCI bus, a n i n du s t r i a l s t a n d a r d P C 10 4 b u s or a n E t h e r n e t c on n e c t i o n . We designed the custom parts as concepts, not around a p ar tic u lar ele ctr o n ic d ev ic e. The waveform generation is as flexible as possible Design from Fasti, reusing as much as possible.












General Structure


Detector board and preamplifier Bias and clock generation, conversion Data buffers, PC104 interface An embedded system as general controller The main data collection PC The user interface PC












Clock Generation
Two different approaches:


Custom micro-controller based (patented), with specialized micro-assembler. It is implemented in a Altera FPGA. Software available: assembler, emulator, visualizer. Very flexible, precious in laboratory, steep learning curve. Programmable sequence of w av ef orm m acros. Also implemented in Altera FPGA, small and fast. Easy to use, but lack the 'what if' flexibility. To be used at telescope.




Sequence emulator display


Preamplifier

12 11 10 D ualFetA 9 T ra n s c o n d u c ta n c e (m A /V ) 8 7 6 5 4 3 2 D ualFet B

C o l d p re a m p l i f i e r. D i s c r e t e c o m p on e n t s ba s e d ( U 4 4 0 D ua l - F E T ) Se l e ct i o n o f FE T s N oi s e p r o p o r t i on a l t o









T/G

m



N oi s e b e t t e r t ha n 2 nV H z B e t t e r r e a d- o ut no i s e

-Ѕ


50 100 150 200 T e m p e ra tu re (K ) 250 300



B e t t e r c r o s s -t a l k i m m u n i t y

Cfr. Biliotti et al. Submitted to AJ, 2006


The acquisition chain hardware


The conversion board The buffer board The embedded system






The conversion boards


4 or more boards: one on each detector output Fast 18 bit AD7674, used at 500KS/Sec Faster 16bit+average option (up to 4MS/Sec) Fault-tolerant design Control logic on a Altera FPGA FlexConnect© to detector cold board Copper or fiber optics LVDS up link Hosts also the biases generation
















The buffer board


Control logic based on a FPGA 2 full frame memory capacity Up to 32 LVDS input capabilities Link to a PC104 or a PCI bus Fifo mode operation Movable memory window mode












The embedded System


An industrial standard single board computer The actual device is a x86 based PC104 board Connected by means of PC104 bus and Ethernet Embedded Linux, Slax server version Flexible, rich in mature libraries and applications Possibility of remote maintenance












Giano software structure


Low Level Software - I Server104


A network daemon inside the embedded system. It does all initialization, housekeeping and control for data acquisition. It communicates by means of a network socket. It programs the waveform generator for the current acquisition mode (correlated double sampling, single reading, multiple non destructive read-out, continuous dummy integrations) and process data. It collects and communicates some of the telemetry.










Low Level Software - II Gbridge


A m i d dl e - w a r e n e t w o r k da e m o n i n t h e d a t a a c qu i s i t i o n c om p u t e r . It acts as server for User Interface, and as client of Server104. I t s p l i t h i g h l e ve l c om m a nd s i n e l e m e nt a r y o p e r a t i o ns , a n d s e nd s t h e l a t t e r t o S e r v e r 1 0 4 . I t c on t r ol s t h e i n t e gr a t i o ns , a s s e m b l e s d a t a a n d a r c h i v e s telemetry in FITS format and sends the resulting files to the a r c hi ve . I t h a s a t e c hn i c a l h u m a n i n t e r f a c e ( G u i L a b ) f o r l a b o r a t o r y and testing purposes.










The internal communication protocol


A single protocol format for all Giano internal communications All communications in packet form and only one packet format. Binary header with destination process ID and checksum. ASCII payload on command and messages for ease of debug Binary scientific data payload for efficiency.










More about Giano


Web general: http://stars.bo.astro.it/giano/documents/documents.html Web technical: http://www.arcetri.astro.it/irlab/doc/doc.php This conference:
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General Optics Mechanics Cryogenics Gui software Calibration

Oliva et al. 6269-46 Gennari et al. 6269-146 Bruno et al. 6269-148 Mochi et al 6263-141 Gennari et al. 6269-147 Rossetti et al. 6274-85 D'Amico et al. 6269-197