x01dcandClaude Sonnet 5 3eb6e0355f
CI for csaxs_bec / test (push) Failing after 2m51s
fix(panda): drop stale frame_counter carryover in Mode B raw stream
Diagnosed against a real scan (S06313): grouping raw interf_st_fzp_x/_y
samples by frame_counter + gate_detector_active reproduces rt_positions'
trusted average_x_st_fzp/_y to R² > 0.9999, confirming that method -- but one
point (167) was off by ~116 nm because PandA's COUNTER1.OUT is not cleared by
Arm(). The first raw samples of an acquisition can briefly carry a stale
frame_counter value left over from the previous acquisition's tail (observed:
36 samples reading a stale 167 before dropping to 0), which silently
contaminates whichever real point later in the same scan happens to share
that counter value.

PandaBoxOMNY now drops raw rows captured before it observes frame_counter ==
0 for the first time in each acquisition -- on every arm, including
on_pre_scan retries, since each Arm() reopens the same stale-value window --
and drops leftover buffered rows from an abandoned attempt at the same point.
Verified against S06313: point 167's residual drops from ~116 nm to ~0.1 nm
after the fix, in line with the rest of the scan.

Write-up, including the diagnostic method and a possible PandA-layout-level
alternative fix, in docs/developer/panda_box_free_running_setup.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NPZ9gzN2rt3wgiMnTKyrug
2026-09-21 20:21:23 +02:00
2025-05-24 11:37:51 +02:00

cSAXS BEC

cSAXS specific plugins and configs for BEC This document guides you through the procedure to spin up BEC at the beamline for a new experiment (e-account). You might want to run cSAXS copy scripts before in case you want to have the former data structure to be preserved.

Overview

  • Clone cSAXS BEC repository into e-account (e.g. into ~/Data10/software/.)
  • Start Epics iocs
  • Start BEC, BEC server and load/modify the device config with relevant hardware
  • BEC commands

Clone cSAXS BEC repository

Clone the current cSAXS BEC repository from GIT into the new e-account. Create directory

mkdir ~/Data10/software
cd ~/Data10/software

Clone repository

git clone https://gitlab.psi.ch/bec/csaxs_bec.git

Start epics iocs

You can start up the iocs while the ./setup_bec.sh script is running. Be aware though that the scripts requires you to interact with it.

DelayGenerator

Open a new tab in a terminal in comp1/comp2 or cons1 and follow the commands below:

ssh gac-x12sa@localhost
cd ~/delaygen
iocsh -7.0.6 startup.script

Be aware -7.0.6 is referring to the current epics version and might change in future (SLS 2.0). To start the epics panel (only if needed), run in a new shell

caqtdm -noMsg -macro P=delaygen:,R=DG1: srsDG645.ui

More notes on usages and cabelling of DDGs. Currently 3 generators are used:

  • DDG1 for detectors (EXT Enable from SGalil stages, T0 to DDG2, AB for eiger, CD for Falcon, EF for Pilatus_2)
  • DDG2 for mcs card (ext. enable from DDG1, AB to mcs card)
  • DDG3 for fast shutter and mcs enable (AB short pulse to enable MCS (needed!!), CD to keep FSH open )

Eiger

Open a new tab in a terminal in comp1/comp2 or cons1 and follow the commands below:

ssh gac-x12sa@localhost
cd ~/Software/Eiger/
./launch_ioc

A live view of status and images for std_daq can be found here xbl-daq-29:5000.

Pilatus_2

First, start the cam server. Connect to the computer and follow the instructions printed after connecting:

ssh det@x12sa-pd-2 (Pilatus2)

The cam server will open, wait until you see **. Nex step, open a new tab in a terminal in comp1/comp2 or cons1 and follow the commands below:

ssh gac-x12sa@localhost
cd ~/Software/Pilatus300K/
./launch_epics

FalconX1

Open a new tab in a terminal in comp1/comp2 or cons1 (logged in as the current e-account) and follow the commands:

ssh x12sa-cons-01
cd /ioc/X12SA-PC-FALCONX1/
iocsh -7.0.6 startup.script

Be aware -7.0.6 is referring to the current epics version and might change in future (SLS 2.0)

Start BEC, BEC server and load device config

Step 1 needs to have finished for continuing with these steps. What remains now is to start the bec server. Connect to pc15543 and open a new terminal to run:

cd ~/Data10/software
source bec_venv/bin/activate
bec-server start
tmux attach -t bec

Open another teminal on pc15543 and start BEC:

cd ~/Data10/software
source bec_venv/bin/activate
bec

Note: In case there is a warning after starting BEC that it was not able to import scilog, you will have to pip install scilog in the bec_venv to be able to send printouts to scilog from the command line. Within a new terminal:

cd ~/Data10/software
source bec_venv/bin/activate
pip install scilog

Device config from csaxs-bec plugins

bec.config.update_session_with_file('/sls/X12SA/data/e20639/Data10/software/csaxs-bec/bec_plugins/configs/bec_device_config_sastt.yaml')
bec.config.save_current_session('~/Data10/software/current_config.yaml')

The second command is helpful if you adjust limits of motors, which will then be stored in the config and loaded if a reload of the configuration is needed.

BEC commands

A number of commands that are useful:

To move devices that are added in the config:

umv(dev.samx, 0) #absolute
umvr(dev.samx, 0) #relative
dev.samx.wm #print motor position and limits
dev.samx.limits = [low_limit, high_limit] # To set limits, note, same lower and higher limit, e.g. [0, 0] means no limits!!

Scans:

scans.acquire(exp_time = 0.5, frames_per_trigger=10, readout_time=3e-3) # equivalent to a loopscan 30 0.5
scans.line_scan(dev.samx, -1, 1, steps=20, exp_time=0.5, readout_time=3e-3, relative=True) # optional, add frames_per_trigger =10 for burst acquisition at each step
#Scan 2 motors in a step scan at the same time
scans.line_scan(dev.samx, -1, 1, dev.samy, -1, 1, steps=20, exp_time=0.5, readout_time =3e-3, relative=True) # step scan with 20 steps, again frames_per_trigger can be added for burst at each point
scans.sgalil_grid(start_y = , end_y = , interval_y = , start_x=, end_x=, interval_x =, exp_time=0.5, readout_time=3e-3, relative=True)
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