sPHENIX tracking discussion

["Huang, Jin" <jhuang AT bnl.gov>]

Dear DAQ team

As my homework from the Tue DAQ meeting, a consensus has reached about how we 
would like to operate the TPC diffuse laser after discussion with the TPC 
operation team at 1008, distortion team, and tracking team. The details are 
summarized in this slide deck discussed in the tracking meeting today: 
https://indico.bnl.gov/event/21877/ 

In quick summary, the laser is fired after a GL1 trigger with a tunable 
standalone busy, which provide a throttling for lower laser rate than GL1 
rate. It would likely require to a readout vGTM busy bits in the GL1 packet, 
so in offline we can reliably tell whether a laser fired following a GL1 
trigger or been busy throttled. Details on the proposed change is summarized 
as option 1 in Page 5. 

Please let us know what you think and anything I can help to move forward.

Cheers

Jin



______________________________

Jin HUANG

Physicist, Ph.D.
Brookhaven National Laboratory
Physics Department, Bldg 510 C
Upton, NY 11973-5000

Office: 631-344-5898
Cell:   757-604-9946
______________________________

-----Original Message-----
From: sPHENIX-trigger-l <sphenix-trigger-l-bounces AT lists.bnl.gov> On Behalf 
Of Martin Purschke via sPHENIX-trigger-l
Sent: Monday, March 18, 2024 6:49 PM
To: Sphenix-trigger-l AT lists.bnl.gov; Mead, Joseph <mead AT bnl.gov>
Subject: [Sphenix-trigger-l] GL1/GTM-focused DAQ meeting tomorrow (Tuesday 
Mar 19), 2pm


Dear all, especially Joe,

we want to pow-wow about what we have and what might still be missing with 
the current GL1/GTM firmware.

Here's the Indico - https://indico.bnl.gov/event/22784/

There are a few others, but central are 2 points -

- there are inconsistencies in how the busy is applied and honored in the 
various modes.
When a vGTM is in local mode, it appears to issue FAs unconditionally. 
We also see that if it is set to accept L1s (in local mode with the 
"GL1_PERMIT" 0xD reg), it doesn't honor its own busy. The desired behavior is 
that in local mode it looks at its own DCM_BUSY_MASK and suppresses a L1 from 
being sent out if we are busy, for both FAs or a GL1-L1.

- the freezing of the BCO values that are sent out with FAs We see this with 
the TPC (only the FELIX-detectors can see it in the first place) that is 
running FAs a lot. Joe said he knows why. The desired behavior is that any 
issued L1 (from FA or GL1-L1) transmits the current BCO.

Other items -
I received v55 that gives us the GL1-P info in the readout data stream, as 
well as a different busy scheme that I'm working to adapt to. It also has the 
2nd switchyard that allows us to cherry-pick the triggers that go on the 16 
GL1-P scalers. That needs testing, obviously. Joe also implemented a way to 
better test the "bunch number sensitivity" - I had earlier tested this in a 
poor man's fashion by using a delayed fiducial tick copy as a Lemo trigger 
that so triggers only on the given bunch, depending on the delay.

There is a new issue that (after we never got vGTM1 to work for reasons
unknown) we now see that on our main unit, vGTM3 / INTT behaves erratically. 
I need a way to see this more directly with some sort of probe, and if we 
cannot resolve this, I probably need Joe's help to get
  to the bottom of this.

Ok. We will start with this. If we are done in time before 3:30, we may have 
time to talk about other, general DAQ things.

See you tomorrow,

        Martin


-- 
Martin L. Purschke, Ph.D.        ;   purschke AT bnl.gov
                                  ;   http://www.phenix.bnl.gov/~purschke
                                  ;
Brookhaven National Laboratory   ;   phone: +1-631-344-5244
Physics Department Bldg 510 C    ;   fax:   +1-631-344-3253
Upton, NY 11973-5000             ;   skype: mpurschke
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