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BFEM Telemetry data vs. Rescued data (4) -- Telemetry data properties --

BFEM Telemetry data vs. Rescued data (4) -- Telemetry data properties --. December 16, 2002 Tsunefumi Mizuno mizuno@SLAC.Stanford.EDU. Trigger rata and telemetry event rate (p.2) Do we understand the telemetry sampling? (p.3) Delta_t distributions (pp.4-6)

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BFEM Telemetry data vs. Rescued data (4) -- Telemetry data properties --

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  1. BFEM Telemetry data vs. Rescued data (4)-- Telemetry data properties -- December 16, 2002 Tsunefumi Mizuno mizuno@SLAC.Stanford.EDU • Trigger rata and telemetry event rate (p.2) • Do we understand the telemetry sampling? (p.3) • Delta_t distributions (pp.4-6) • Delta_L1tCount distributions. (pp.7-9) • Relation between data size and delta_t (pp.10, 11) BFEM telemetry sampling is complicated and we have not succeeded in reproducing it yet. In this memo, I summarize the telemetry data properties hoping that they help us to understand the sampling mechanism.

  2. Trigger rate and telemetry event rate • We need to know the trigger rate and telemetry event rate because they could affect the way telemetry samples the data. Below, rates of Run53 (before the flight), Run54 (during ascent) and Run55 (level flight) are summarized. Run54 consists of 16 small runs, and run #0, #2, #3, #5, and #6 are recovered from hard disk (“rescued data”). Run53 (before flight) Run54 during ascent) Run55 (level flight) #3 #5 #6 #2 trigger rate #0 telemetry event rate Figure 1: Trigger rate (upper figures) and telemetry event rate (lower figures).

  3. Do we understand the telemetry sampling? • We thought that telemetry sampling mechanism is easy and straightforward. The sampling algorithm is as follows. • The size of buffer is 25kbyte • Telemetry reads data with rate of 25kbyte/s • For every event, event size is compared with a free space in the buffer • If there is enough space, write data to buffer. If not, do nothing. • Does this algorithm reproduce the data? See Figures below. We have not yet understood the telemetry mechanism. To understand it, we need to know the telemetry data in more detail. delta_L1tCount delta_t TKR data size Rescued data, sampling algorithm is applied telemetry data Figure2: Delta_L1tCount (left), delta_t (middle) and TKR data size (right) distribution of run#5 in Run54. Telemetry data and rescued data (after the sampling algorithm is applied) are compared.

  4. delta_t distribution of Run53 • In Run53, trigger rate (~19Hz) exceeds the telemetry event rate limit (~12Hz). However, delta_t distribution in telemetry data preserves the property of original events. Figure3: delta_t distribution of Run53, data before the flight. In small delta_t region, the distribution obeys exponential distribution of rate~19Hz. exponential distribution of tau=0.526s (19Hz)

  5. Delta_t distribution of Run54 • Delta_t distribution of Run54 has some interesting properties to be understood. They are as follows. • The distribution has two peaks. • The width of the peak depends on trigger rate. • The position of the peak does not depend on trigger rate. Trigger rate ~ 1.2kHz Trigger rate ~ 500Hz Figure4: Delta_t distributions of Run54.

  6. Delta_t distribution of Run55 • Delta_t distributions of Run55 are quite similar to that of the last run in Run54. Trigger rate ~ 500Hz Figure 5: Delta_t distribution of Run55.

  7. Deltla_L1tCount distribution of Run53 #eventNo runCount l1tCount deltaL1tCount time deltaTime size 0 4 2362 0 121.9546197 121.9546197 1820 1 4 2363 1 121.96650925 0.01188955 1820 2 4 2364 1 122.0497416 0.08323235 1800 3 4 2365 1 122.2542353 0.2044937 1844 4 4 2366 1 122.26198345 0.00774815 1840 5 4 2367 1 122.34521875 0.0832353 1824 6 4 2368 1 122.35294895 0.0077302 1780 7 4 2371 3 122.41682985 0.0638809 1768 8 4 2372 1 122.43723185 0.020402 1796 9 4 2373 1 122.47480865 0.0375768 1824 10 4 2374 1 122.51359235 0.0387837 1788 11 4 2381 7 122.82771535 0.314123 1788 12 4 2382 1 122.8277943 7.89499999883e-05 1848 13 4 2383 1 122.92686035 0.09906605 1760 14 4 2384 1 122.93835175 0.0114914 1804 15 4 2385 1 122.9605948 0.02224305 1836 16 4 2391 6 123.2076196 0.2470248 1868 17 4 2392 1 123.3410519 0.1334323 1756 18 4 2393 1 123.404386 0.0633341 1824 19 4 2394 1 123.4435602 0.0391742 1768 20 4 2395 1 123.49557565 0.05201545 1800 21 4 2396 1 123.49863615 0.00306049999999 1780 22 4 2401 5 123.64569315 0.147057 1788 23 4 2402 1 123.68442905 0.0387359 1788 24 4 2403 1 123.6997522 0.01532315 1800 25 4 2404 1 123.7810644 0.0813122 1860 26 4 2405 1 123.83214985 0.05108545 1840 27 4 2406 1 123.8869122 0.05476235 1932 28 4 2411 5 124.16774435 0.28083215 1836 • Increment of the L1T count is studied for Run53, and a periodicity is observed. Something happens for every 10 events. Figure 6: (upper) Delta_L1tCount distribution. (right) L1T count, time, data size, etc. of Run53.

  8. #eventNo runCount l1tCount deltaL1tCount time deltaTime size 0 1 1 0 0.1574671 0.1574671 1788 1 1 2 1 0.1733494 0.0158823 1820 2 1 3 1 0.18562775 0.01227835 1784 3 1 4 1 0.1912049 0.00557715 1768 4 1 5 1 0.2153597 0.0241548 1844 5 1 6 1 0.23545425 0.02009455 1796 6 1 7 1 0.2435615 0.00810725 1836 7 1 8 1 0.2491269 0.0055654 1840 8 1 9 1 0.2577922 0.0086653 1812 9 1 10 1 0.27889255 0.02110035 1808 10 1 11 1 0.35064095 0.0717484 1836 11 1 12 1 0.35543905 0.0047981 1816 12 1 13 1 0.4038629 0.04842385 1828 13 1 14 1 0.4040319 0.000169 1844 14 1 15 1 0.4570617 0.0530298 1784 15 1 16 1 0.5319549 0.0748932 1788 16 1 17 1 0.544143 0.0121881 1808 17 1 18 1 0.59495515 0.05081215 1788 18 1 21 3 0.6578561 0.06290095 1832 19 1 22 1 0.66027255 0.00241645 1784 20 1 23 1 0.70666675 0.0463942 1820 21 1 24 1 0.7215709 0.01490415 1796 22 1 25 1 0.7277854 0.0062145 1844 23 1 26 1 0.75773185 0.02994645 1804 24 1 31 5 1.069791 0.31205915 1816 25 1 33 2 1.12162315 0.05183215 1780 26 1 35 2 1.14139685 0.0197737 1840 27 1 41 6 1.3051762 0.16377935 1852 28 1 42 1 1.3252517 0.0200755 1988 29 1 43 1 1.36044865 0.03519695 1800 30 1 44 1 1.3970339 0.03658525 1836 31 1 45 1 1.40155845 0.00452455 1792 32 1 51 6 1.66041425 0.2588558 1812 • Again, the periodicity is observed. We also see a quantization in delta_L1tCount distribution. Deltla_L1tCount distribution of Run54 Trigger rate ~ 1.2kHz Trigger rate ~ 500kHz Figure 7: The same as Figure 5 but for Run54 instead of Run53.

  9. Delta_L1tCount distribution of Run55 #eventNo runCount l1tCount deltaL1tCount time deltaTime size 0 9 105048 0 212.50643245 212.50643245 1848 1 9 105097 49 212.60309645 0.096664 1856 2 9 105155 58 212.7303804 0.12728395 1816 3 9 105193 38 212.79652315 0.06614275 1856 4 9 105231 38 212.8795398 0.08301665 1816 5 9 105310 79 213.02768045 0.14814065 1784 6 9 105330 20 213.07538085 0.0477004 1836 7 9 105380 50 213.1563338 0.08095295 1792 8 9 105429 49 213.227591 0.0712572 1816 9 9 105457 28 213.2962297 0.0686387 1828 10 9 105486 29 213.35964095 0.06341125 1884 11 9 105533 47 213.4498159 0.09017495 1812 12 9 105563 30 213.51941515 0.06959925 1836 13 9 105601 38 213.5815389 0.06212375 1800 14 9 105689 88 213.7374533 0.1559144 1780 15 9 105709 20 213.79389425 0.05644095 1760 16 9 105747 38 213.86998735 0.0760931 1784 17 9 105787 40 213.9413496 0.07136225 1832 18 9 105855 68 214.082666 0.1413164 1772 19 9 105892 37 214.15148545 0.06881945 1820 20 9 105922 30 214.2274421 0.07595665 1800 21 9 105951 29 214.28738975 0.05994765 1844 22 9 106000 49 214.37289235 0.0855026 1808 23 9 106039 39 214.4451837 0.07229135 1776 24 9 106106 67 214.57648865 0.13130495 1932 25 9 106136 30 214.63917315 0.0626845 1840 26 9 106166 30 214.71205585 0.0728827 1820 27 9 106195 29 214.7842712 0.07221535 1776 28 9 106223 28 214.8482916 0.0640204 1816 29 9 106253 30 214.93362335 0.08533175 1816 30 9 106283 30 215.00544805 0.0718247 1816 • Again, quantization in delta_L1tCount is observed. Trigger rate ~ 500kHz Figure 8: The same as Figure 5 but for Run55 instead of Run53.

  10. How TKR data size depends on delta_t? (1) • Data of Run54 is sorted based on delta_t and TKR data size is histogrammed. If the event is in the first peak in Figure 4(delta_t<=0.11s), the event of larger delta_t tends to show larger data size. However, the event in the second peak (delta_t>=0.11s) does not show such property. 0.000s<=delta_t<=0.060s 0.060s<=delta_t<=0.072s 0.072s<=delta_t<=0.090s 0.090s<=delta_t<=0.110s 0.110s<=delta_t Figure 9: TKR data size distribution of Run54, where events is divided into 5 based on delta_t.

  11. How TKR data size depends on delta_t? (2) • Data of Run55 has similar property to that of Run54. The event of larger delta_t shows larger data size, but this tendency is not seen when the delta_t is too large. (delta_t >= 0.11s, second peak in Figure 5) Figure 10: The same as Figure 8 but for Run55 instead of Run54.

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