Dear,
Here is a summary of CREAM-IV flight preparation status on the 9th of November at McMurdo.
- The remaining LPT with SCD, Chercam and TCD was done OK except the following known problems. So the instrument is OK after the shipment.
- The top SCD shows some bad channels as seen at the Palestine before shipping but with similar numbers. This is what we expect to fix by cleaning up the Actel chip pins with rubber eraser.
- By touching the HSK data cable, they become normal from time to time. Even though this problem thought to be resolved by re-connecting the connector #13 in the HSK main board in CSBF, it maybe due to a bad connection in the HSK data cable connector at the top I/O board. I will try to re-connect the #13 connector tomorrow and see if this would solve the problem again or not. Antje will contact with Laurent whether it is OK or not in case when the problem would not be solved.
- The TCD readout cdaq software modifications based on his debugging of the TCD codes were explained by Tyler today. They can be summarized from his presentation slides at the CREAM tele-con as follows.
- There is almost no latency from the network between concentrator. From a lab test, we estimated that the network latency is about 1.1 ms and would be about 2.2 % dead time with 20 Hz.
- One of major bug is in time out of 100 ms related with the event number. In case when pxl event number is bad, it waits for 100 ms even though the event number is good.
- The waiting time for the event number is 27 ms and is too long compared with a lab test time of about 0.5 ms.
- The concentrator time out for polling is 100 ms and can be reduced if the above 2 do not improve.
- All the above bugs are simple to modify.
- Based on his explanation and suggestion, Prashant explained how the event numbers are generated and compared in the cdaq program.
- Since there are no risks in trying the modifications, we can try the modification from tomorrow if there are no questions/concerns. The existing code will be kept safe by not deleting the old code. And also when the modification does not work, it will go back to the original code again. Even though the modification seem OK, the code will be tested by having long enough flight mode runs (maybe for about 3 days of run in total of about 30 hours). Please let us know if there are any concerns/questions by tomorrow 5 PM (EST). Unless we hear any, we will try this modifications.
- From tomorrow, we will work on the followings before the CPT.
- Cleaning of tSCD sparsification board Actel chip pins.
- Chercam HSK problem debugging.
- TCD HV HSK attenuation circuit correction.
- Installation of two SSDs into the SFC and test.
- Tightening of a loose connector in the SFC1.
- TCD code modification and test if it is approved OK.
- The TCD readout cdaq software modifications based on his debugging of the TCD codes were explained by Tyler today. They can be summarized from his presentation slides at the CREAM tele-con as follows.
