menzel
3ddd0d7957
The first point of every line is under-exposed. Four commissioning scans
put a number on it, against the 2e-3 head start that was in place:
scan exp_time first/near lost
324 15 ms 0.655 5.18 ms
254 20 ms 0.732 5.36 ms
411 50 ms 0.881 5.93 ms
450 50 ms 0.879 6.04 ms
A fixed time, not a fixed fraction: it varies by 17% across a 3.3x range
of exposure while the fraction varies by 2.9x. The same deficit appears
on the integrated scattering, a different detector behind a different
gate, so the cause is upstream of both readout chains rather than in
either of them. 2e-3 allowed and ~5.6e-3 still lost means the shutter
needs about 7.6 ms, rounded up to 8 ms: the spread across the four scans
is 0.9 ms, so the third digit is not meaningful, and overshooting costs
only the difference in dead time at the start of each line.
The trigger scheme was already right -- the shutter fires on cd at t0
and the acquisition on ab is held back by _shutter_to_open_delay, with
the widths, burst_period and cont_grid's acc_time and premove all
derived from it. Only the value was wrong, and it was a literal in two
places, so setting one and not the other would have been silently undone
by keep_shutter_open_during_scan.
Lifts it to DEFAULT_SHUTTER_TO_OPEN_DELAY next to the other defaults,
with the measurement recorded, and adds set_shutter_to_open_delay to
USER_ACCESS so the value can be converged from the client instead of by
redeploying the device server. It is bounded, because a delay is paid on
every line and a fat-fingered value would stretch the scan rather than
fail.
Cost at the new value is 6 ms per line -- 0.26 s over scan 450 -- and
0.8 um of extra premove.
The existing stage test asserted the 2e-3 literal and now asserts the
constant. New tests cover the default, the bound, the USER_ACCESS entry,
that a set value actually reaches the ab channel while cd still fires at
t0, and that keep_shutter_open_during_scan discards a tuned value, which
is a sharp edge worth pinning rather than leaving to be rediscovered.
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)