20181024-Analyzer-Mtg

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github repository: JAPAN

Agenda

1. Cavity BPMs
   • CG: John Musson, Ye, and Cirprian looked at Cavity BPM signals on a scope last Friday.
   • CG: It looks like the receiver box's output DAC is not configured correctly, and so a test of this firmware is being done by Trent and Musson.
   • CG: As a backup, it may be possible to bypass the DAC conversion by using a fiber optic cable to take the original signal instead.
     • KP: We should ask them to give us a good analog signal.
     • Bob: One goal is for SEE BPM cross-checking, but another is for low-current EPICs variable data collection (already implemented), in which case an already-digital readout is desirable, particularly for commissioning.
     • Ye Tian will work with Ciprian and Musson to follow through on this.

1. et_bridge
   • Carl Timmer helped Bob recompile and get it working (Bob's notes).
     • Bob: Memory mapped file deletion was a problem, and has been fixed, so the 2-ET system is working fine now.
   • Cameron used it and tested it for deadtime here.
     • Bob: Why is there deadtime at all? 1kB size events should not be a problem. Buffering of events in series may help.
     • KP: Why measure deadtime like this? PK: Implement a counter in the VXWorks ROC software, and see if there are any skips there. Bob: Implement a scaler in the crate that will count the number of helicity flips - also it would be good to recreate the helicity information to see that no gaps appeared.
     • KP: Each data buffer has an index associated with it that can be tracked to see how many buffers are lost.
     • PK: Techniques exist for looking at ET's efficiency of moving data around, and ways exist for interrogating the ROCs buffers to find the bottleneck. Bob: Putting events back will allow us to use the ET more dynamically and make a copy of all events to file (to compare stored vs. analyzed).
     • Bob: Check that this wasn't accidentally run in blocking station mode (which would make it slower).
     • PK: Set the ET buffer to a larger number and see if that smooths out network traffic problems.

1. WAC: online analysis scripts
   • Ciprian will look at online analysis scripts, and possibly ask Cameron to help as well

1. inclusion of HAPPEX ADCs
   • Bob: Getting mnemonic device names to work is proving non-trivial, but progress is being made.
     • CG: Doxygen is hosted on Hall A Web and can be used to track class inheritance, etc.

1. naming conventions:
   • See Cameron's commit and comment on issue 22.
   • PK: Don't use a placeholder "ble" class name (the 4th word in the .map files is the japan class name).
     • PK: You can just skip unknown channels and not include them in the map.
   • PK: The BCM class is possibly not working, but should be used as the general default for getting a signal decoded.
   • KP: What 4th word class name should be used? PK: Will check later in the code - "bcm" is generic, but "ble" should be replaced with either an empty data type or the general type of bcm class
     • PK: The 4th word is just used by the .map file to indicate the class to be used, the 5th word should be "bpm", "cav", "bcm" + _ "channel name indicator"
     • KP: 5th word variable names - underscores? Changing cm_us and cm_ds to bcm1 and bcm2 should be sufficient.
     • PK: For example: the SEE BPMs 4 x, y, p, m channels are parsed (the trailing XP, etc. are removed) and new parallel branches are calculated and stored - leaves are sub-blocks and hardware sums. Similarly for Cavity BPMs (cavity class hasn't been written yet, but should be temporarily replaced with 3 "bcm" instances).

1. cavity BPM and configuration files (japan and pan): Ciprian, Bob, Cameron
   • Bob fixed the control.db in
2. BPM pedestal calibration

Present

Cameron, Bob, Paul King, Tao Ye, Ciprian

Excused

Ciprian