Notes about PAS operations
2022/08/22 Last meeting with Andrei
PAS procedures duration
In the following formulas:
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Config_procedure[s]
= 715 + 25* <CEM_Nominal_Voltage[V]>/50 + 30 -
Calibration_procedure[s]
= 24*<Nsteps of CEM HV> +10 sec ; Nsteps_of_CEM_HV = ROUND((STOP_HV - START_HV)/50 + 1.0) -
TTF_Recovery[s]
= 210 + 25* <CEM_Nominal_Voltage[V]>/50 + 30
CEM_HV are computed from hexadecimal ADC raw values to V using 1.221 coefficient.
This conversion can gives decimal values like 1799.754V rather than expected 1800V, and the integer division by 50 can give differents results than rounding to the nearest integer nb_steps.
int (1799,754 / 50) = int (35.99) = 35 steps
round (1799.754 / 50) = 36 stepsQ1) Indicate if we have to use round() or integer division to compute number of steps, as it may change the computed duration.
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Andrei> by email of 2022/08/21 Use round() to compute nb_steps |
PAS STATIC mode checks
Rules for PAS ON procedure after PAS switch on beginnning of STP or at 00:00, 06:00, 18:00:
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We have to start NM (AIAF061A) AFTER the 300 s SCET boundary, in the time interval [ 20 : 90] or [120 : 190] seconds offset after the 300 s SCET boundary
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We have to stop NM 100s (AIAF063A) (+/- 5 s) after the start.
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We can restart STATIC in 20 s after the NM stop
In default IORs prepared byt MSSL, there is a default delay of 01:50 = 110s between PAS_Start_science and PAS_Stop_science
This 110s delay breaks rule 2) and will need a lot of modification in further STPs
⇒ 25 x 2 commands to modify for each STP
Q1) Do we have to change Rule 2) or modify the MSSl default procedures duration?
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To be completed |
Previously we used the following check:
(PAS_Start in [20,90] and PAS_stop in [120,190]) OR (PAS_Start in [120,190] and PAS_Stop in [220,290])Q2) Why so restrictive rules (100s +/5s )? Is the 100s duration really mandatory?
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To be completed |
PAS calibration duration
Duration computation
In table 9, the PAS calibration duration is defined as:
24 * nb_steps_of_CEM_HV + 10sWith:
nb_steps = round ((STOP_HV - START_HV) / 50 + 1.0)In latest figure 27, the duration seems to be computed as:
432s + 00:14 = 07:26 ; 432 corresponds to 24 x 18 stepsWhere 00:14 duration comes from?
What is the formula to use?
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To be completed |
PAS stop science constraints
I don’t understand the constraints for PAS Stop TC :
> 10s after first FS (offset 100 )
< 60s after first FSQ1) Where 60s comes from?
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To be completed |
Q2) Could we stop after second FS?
In the same way we allow PAS_stop on range [110, 160], can we allow PAS_stop on range [210, 260] ?
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To be completed |
