1. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell1 October 16, 2001 What’s Covered Activity –Monitoring FSW defines this as activity that goes on in parallel with normal data taking –Diagnostics FSW defines this as activity that puts the LAT in a mode that is incompatible with normal data taking –Charge Injection Calibration Not Covered today, way too big of a topic… Data Sources and Types –Hardware registers –Normal events –Special Triggers –Special Filtering –Special Modes 4 – range readout Non-zero suppressed Diagnostic Mode readout

2. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell2 October 16, 2001 TKR Monitoring 5.3.8.1 - TKR Occupancy –Purpose Monitor live and dead channels –Proposal Transfer this responsibility to the ground –Rational They can do as good if not better –Justification Need to get ~100 events to find a hot channel At 10 -4 occupancy, one needs 10 6 events Best one can do is 100 seconds (10KHz)’ If get from 400Hz downlink, will take 2500secs –But could get much better S/N »Can remove real hits Similar arguments for dead channels

3. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell3 October 16, 2001 TKR Monitoring 5.3.13.2.5 TKR GTRC Rates –FSW has asked for clarification here –The requirement reads Upon receipt of the appropriate command, the date rate of each GTRC for random trigger (rate > 100Hz) and the trigger rate for each layer (or GTRC, as a goal)) shall be determined and forwarded to the SC for downlink. (Total data size: ~9Kbytes). Note that three sets of configurations are necessary to measure 36 layers in a tower. One minute per set will be sufficient. –What is the data source? The hardware registers on the TEM? The diagnostic output? HELP!!!

4. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell4 October 16, 2001 ACD Monitoring 5.3.8.2 Monitor ACD Veto Rates from GEM –Purpose Watch for abnormal and changes in behavior –Proposal Define a program specifying a series of –Tile pairs and durations Code will –Initialize the MUX (starting the counters) –Read the counters after the specified duration –Stash the time tagged results away –Flush the buffer at the end of the series –Up to the user to avoid saturation of the 16-bit counters Rational –This must be done onboard

5. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell5 October 16, 2001 ACD Monitoring 5.3.8.2.2 Monitor L1 Trigger Rates 5.4.8.3.3 Monitor CNO Rates –Purpose Watch for abnormal and changes in behavior –Proposal Formalize the current ACD software counters Add commands to control the accumulation –Time duration –Event Selection –Rational Not a candidate for offline processing Downlinked data sample –Too biased –Too slow to accumulate

6. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell6 October 16, 2001 ACD Diagnostics 5.3.13.2.1 ACD Trigger Mode –Purpose Check each of the tile ends –Proposal This is a matter of reconfiguring the trigger Will provide a means of –Defining trigger parameters as a named file –Loading a trigger file into the trigger.

7. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell7 October 16, 2001 CAL Monitoring 5.3.1.13.1.2, &.6 CAL Log-Accept Occupancy Histograms –Don’t see a difference between.2 &.6 5.3.1.13.1.3 &.8 CAL Range Occupancy Histograms –Don’t see a difference between.3 &.8 –Purpose Look for abnormal or changes in behavior –Proposal Transfer this responsibility to the ground –Rational They can do as good if not better However, have made a first pass (combining the two requirements) –Accumulated 256 histograms of 96 channels each Indexed by tower (16) and Range Bits (4 range bits = 16) Takes ~5usecs/event to accumulate Compressed size is in the 5-15Kbyte range

8. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell8 October 16, 2001 CAL Monitoring 5.3.13.1.4 CAL Log-Accept Occupancy Rate, from diagnostic contribution –Purpose Check that the hardware bits indicating the channel selection match the data –Proposal Since accumulated with CAL in diagnostic mode –Cannot do during normal data taking Either –Transfer this responsibility to the ground or… –Define a set of histograms that indicate the mismatching »The current output will not indicate specific errors and, can, in fact, look perfectly fine, when things are broken

9. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell9 October 16, 2001 CAL Monitoring 5.3.13.1.5 &.7 CAL Trigger Request Rates, from diagnostic contribution –Purpose Check the transmission from the TEM matches the GEM data. –Proposal Since accumulated with CAL in diagnostic mode –Cannot do during normal data taking Either –Transfer this responsibility to the ground or… –Define a set of histograms that indicate the mismatching »The current output will not indicate specific errors and, can, in fact, look perfectly fine, when things are broken »Think doing this correctly on board is difficult

10. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell10 October 16, 2001 Cosmic Ray Calibration 5.3.13.1.1 ACD Cosmic Ray 5.3.13.1.9 CAL Cosmic Ray 5.3.13.1.10 TKR Cosmic Ray –Purpose Use a known sample of events to monitor subsystem –Proposal Each subsystem describes a different trigger & selection criteria FSW would like some agreement between them Need criteria for both –1 MIP Cosmics –CNO’s –Rational Too confusing

11. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell11 October 16, 2001 Cosmic Ray Calibration TYPETRIGGER 1 MIP Cosmic 3-in-a-row CNOACD-HI & 3-in-a-row SELECTION CRITERIA Non-showering Complete CAL penetration Strong of a single track Adjacent towers (some %) Your Suggestions Here…

12. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell12 October 16, 2001 Pedestal Data 5.3.13.2.2 ACD Pedestal Data 5.3.13.2.3 CAL Pedestal Data 5.3.13.2.4 CAL Pedestal Histogram Data –Purpose Find the pedestals of the channels by –Taking events in non-zero suppressed mode –Histograming the channels ‘around’ the pedestal –Proposal Put the detector in 4-range, non-zero suppressed mode Take ~10K events Let the ground analyze the data –Rational They can do a better job, particularly in getting rid of coherent effects.

13. GLAST LAT ProjectGLAST Flight Software IDT, October 16, 2001 JJRussell13 October 16, 2001 Pedestal Data Is this feasible? –Event Size ACD – Raw, 504 bytes –Compressed, ~250 bytes CAL –Raw, ~25Kbytes –Compressed, ~10Kbytes (need to check this) –Estimate need ~10K Costs 100Mbytes = 800Mbits @1.2Mbits/sec = 800 secs –Equivalent to 15 minutes of data at full rate.