Hall C DAQ
Contents
- 1 How to kill/reset/restart the DAQ, or, "The DAQ is dead, now what..."
- 2 How to bring up the DAQ screens on a workstation
- 3 If you need to reboot a ROC
- 4 Live Time Display
- 5 Setting Prescales
- 6 Expert notes
- 7 EDTM Settings
- 8 F250 Pedestal Updates
How to kill/reset/restart the DAQ, or, "The DAQ is dead, now what..."
How to connect to VNC session
ssh into cdaq@cdaql1 and from there type: go_nps_daq or go_coin_daq (they are the same).
However, you most likely already have those screens on one of the hcdesk machines.
If you are connected to the appropriate DAQ vncsession
If you are connected to the appropriate DAQ vncsession and CODA has hung or gotten into a funny state, then bring a terminal window to the foreground and type the appropriate kill and start script, see below.
% killCoin for coincidence DAQ. (kcoda for NPS-standalone)
Wait for a bit (10 sec). Then restart coda by typing this in the same terminal:
% startCoin for coincidence DAQ. (startCoda for NPS-standalone)
A note about the "platform", which is one of the CODA components that runs on the workstation like cdaql6. It should be running using "systemd". But things can go wrong here, so see the Expert link https://hallcweb.jlab.org/wiki/index.php/Hall_C_DAQ#Expert_notes
You will then have to complete the 'standard' CODA steps:
- Choose 'Platform:Connect' from the CODA Run Control GUI menu bar. ( comment : need add which cdodaconfig to use )
- Click on the 'Tools' icon.
- Then you should be able to start a run as usual.
If you the components can't connect, it may be that the platform has a problem.
If the kill / start process doesn't work
If the system does not restore using the kcodaCoinc/startCoinc procedure, then you may need to reboot the ROCs following this process
Hall_C_DAQ#If_you_need_to_reboot_a_ROC.
If the CODA vnc session disappeared and 'go_coin_daq' doesn't work
NOTE: Ask a DAQ expert and/or the RC before you do this. It really should never be needed.
If everything disappeared and 'go_coin_daq' doesn't work then you can bring things up from scratch outside the VNC session. (It usually means the vncserver didn't start on cdaql6, so you could login to coda@cdaql6 and type /home/coda/coda/scripts/startVnc, but that's supposed to happen in cron.)
COIN Mode
This should be our production mode for the experiment.
% ssh coda@cdaql6
In that terminal, run:
% startCoin
NPS standalone
% ssh coda@cdaql6
In that terminal, run:
% startCoda
If the Event Builder (PEB) dying or not fully ending
There is a chance that when the run ends, the event builder (PEB) will not fully end. It goes to the state "ending" and the DAQ is frozen. The solution is simple: find the event builder (usually a light-blue xterm with the title PEB1), and ctrl-C to exit the event builder, and wait. The PEB will restart on its own and you can start a new run. Sorry, this is a bug in CODA, and the chance of this happening appears to increase if we run with blockLevel>1 and especially if we use USER-end events.
Another possibility is that the event builder may die. This often means there is a memory issue on one of the ROCs. It is simplest to follow the Reboot ROCs procedure to resolve this.
How to bring up the DAQ screens on a workstation
The DAQs run inside their own VNC sessions. They can be brought up on any of the Hall C Counting House machines by running these commands logged in as the 'cdaq' user:
go_coin_daq ... coincidence configuration. NPS + HMS crates.
go_nps_daq ... NPS standalone.
HMS standalone ? Deprecated, but see https://hallcweb.jlab.org/wiki/index.php/Hall_C_DAQ#Expert_notes
Generally, a crate can only operate with one running DAQ.
If you need to reboot a ROC
If a ROC gets in a really bad state, its crate may need to be power cycled using the procedure and links below.
It pays to be a little patient with this process. Stagger turning the crate power back on by 10--20 seconds. For example, turn on hccrate01, wait 10s, turn on hccrate02, wait 10s, etc...
NOTE: Open a browser window in the CODA VNC session (usually there is one already running in the left-most workspace). All of the crate reset links are there along with stored login credentials.
COIN mode
Coincidence (COIN) mode uses both the NPS and HMS ROCs, so you will need to reboot all of them using the links in the two sub-sections below.
After you have power cycled all the ROCs, wait for 2--3 minutes then run kcodaCoin; and startCoin.
- Make an hclog when you do this!
kcodaCoinc is synonymous with killCoinc. A note: SHMS is not used during the NPS experiments.
HMS
The HMS has three ROCs. Follow these links to power-cycle:
- ROC01 (Counting House Electronics Room)
- ROC03 (HMS Electronics Hut -- the wire chambers)
- ROC05 (Counting House Electronics Room) --- On APC switch. See note below.
NPS
The NPS has five ROCs and five VTPs. The VTPs get power cycled when you cycle the ROCs.
- npsvme1 and npsvtp1 (NPS crate 1)
- npsvme2 and npsvtp2 (NPS crate 2)
- npsvme3 and npsvtp3 (NPS crate 3)
- npsvme4 and npsvtp4 (NPS crate 4)
- npsvme5 and npsvtp5 (NPS crate 5)
Reboot them by clicking on the link, and cycling the power. Wait for 10s after clicking the 'power' button before clicking it again. The page will automatically refresh when it is ready.
After you have power cycled all the ROCs, wait for 2--3 minutes then run the appropriate script (killCoin / startCoin).
ROC5/hccrate05 is on an APC switch. Pick the 'Outlet Status' Tab; click on On to the left of hccrate05 on Outlet 1. Set the Control Action to Reboot Delayed, click the checkbox to the left of hccrate05, then click the Next>> button and click Apply on the next screen. If you know where hccrate05 is in the Counting House Electronics Room, you can power cycle it with the switch on the front panel. Turn it off, wait 5 seconds, and turn it back on.
- Make an hclog when you do this!
Rebooting the DAQ computers
In rare instances, we have to reboot the cdaql5 (HMS) and/or the cdaql6 (coinc or NPS) computers. This is best done under the guidance of the DAQ expert, but the link to the general procedure is documented here: https://logbooks.jlab.org/entry/4123883
Live Time Display
In should be visible on rcgui. There is tab in the lower right area of the GUI.
Setting Prescales
Run the prescale GUI using one of these commands from a terminal in the coincidence DAQ session. Do this from a terminal in the appropriate CODA VNC session.
% go_prescale_COIN
Sometimes go_prescale_COIN returns an error message below. Sadly, this might happen several times in a row. Keep trying to start it. Eventually it will start and it will work. The long-term solution is to rewrite this GUI, since the original author / maintainer is long gone. Error in startup script: can't read "config ... (etc)"
How to pick a prescale value
The relationship between the prescale setting and the actual prescale value is somewhat complicated. You can click on the 'Help' button for details.
- The best way to do it is to type in the prescaled rate you want into the Target Rate field and hit return. The Prescaled Rate field will update to show you the rate the DAQ will be accepting.
- You can try adding or subtracting '1' to the 'Value' field if you want to try to tweak the Prescaled Rate a bit.
NOTE: You MUST hit SAVE *before* starting the run!
Details of prescale are in coda-flags.dat attached to each Start-of-Run logbook entry
The new TI has 4 bits to prescale the individual inputs.
- Set psN=-1 to DISABLE that trigger.
- Set psN=0 for NO PRESCALING (ie. accept all)
- The way the input rates are prescaled follows
- input-rate/(2^{val - 1} + 1)
- So, for 10,000 Hz on the input
- val scale_factor prescaled rate example
- 0 -> 1 100kHz ->100000 Hz
- 1 -> 2 100kHz -> 50000 Hz
- 2 -> 3 100kHz -> 33333 Hz
- 3 -> 5 100kHz -> 20000 Hz
- 4 -> 9 100kHz -> 11111 Hz
- 5 -> 17 100kHz -> 5882 Hz
- 6 -> 33 100kHz -> 3030 Hz
- 16 -> 32769 100kHz -> 3 Hz
If the scaler rates in the prescale GUI are not updating
This can happen after CODA gets in a funny state, for example.
- Quit the prescale GUI (Exit button)
- Run the GUI again (as above).
Expert notes
Most shifter workers may not need these notes. But it's a reminder to the experts.
How to adjust blockLevel and bufferLevel. The bufferLevel (normally 10) can still be adjusted with the prescale gui (go_prescale_COIN), which writes to a "flags" file. The program running on hcvme01 parses this flag file and programs the DAQ. New to Fall 2023, we can also adjust the blockLevel, but only by editing the flags file directly. An expert can do this. It's not possible to adjust the blockLevel in the prescale gui.
A note about the vncserver. It may happen that vncserver didn't start on cdaql6. I think I fixed this, but it's easy to check. Login to coda@cdaql6 and type "ps axw | grep vnc". If it's not running, type /home/coda/coda/scripts/startVnc.
What if cdaql6 goes bad ? We should still be able to run on cdaql5 or another cdaq. Just ensure that the environment is valid (see below). There could be some remnant in the log-in scripts or in coda scripts which relies on cdaql6; ideally not.
[coda@cdaql6 ~]$ echo $EXPID NPS [coda@cdaql6 ~]$ echo $SESSION NPS
and these are currently "HMS" on cdaql5, which is sometimes used for HMS standalone DAQ.
"I'd like to run HMS Standalone DAQ".
You are encouraged to run with the "coinc" configuration whenever you need the HMS crates. It has all the crates and the timing is fine. Still, there could be some reasons to force you to use the HMS Standalone DAQ, which runs on coda@cdaql5 and has EXPID and SESSION set to be HMS. There are two awkward steps to switching : see https://logbooks.jlab.org/entry/4168506. If there seems to be a big demand for this DAQ, we should try to automate this switchover, so that expert intervention is not needed. However, the expert can do the job in 10 minutes.
Once you do start the HMS-standalone DAQ use
HMS-standalone DAQ Before doing the stuff below, check if HMS-standalone DAQ is already running. From cdaq@cdaql1 type "go_hms_daq" to open the VNC session for the HMS. If it's not running then on coda@cdaql5 killHMS -- to kill processes startHMS -- to start CODA.
Some things to know about the configs:
The "Coinc" and "NPS"-standalone both run on cdaql6 and switching between them is just a matter of picking the config in rcgui. The "HMS"-standalone is compatible with running "NPS"=standalone, which would be a motivation for using it.
A note about the "platform". The platform is one of the CODA components that runs on the workstation like cdaql6. It should be running 24/7 and is started with "systemd". If you don't see the platform in the process list (ps -awx | grep -ai platform) then typing "platform &" on coda@cdaql6 (assuming we're running the DAQ on cdaql6) will start it, but make sure you're not running the platform twice. On some rare occassions it may be necessary to restart the platform. In that case, "kill -9" all the platform instances and restart it (see below). For the HMS-standalone, the platform is started on cdaql5. killHMS and startHMS will kill and restart the platform. We've found from experience that not killing/restarting is best, because I guess there is some slowness in the initialization, so it's a little better (but not a million times better) to have the platform running 24/7 and not kill it.
Ole Hansen enabled sudo access for the cdaq and coda accounts on cdaql6 for sysemctl (start|stop|restart) platform.service. So you can do this yourself. If and when necessary, e.g. if it's hung up, terminate the running platform process, along these lines: [coda@cdaql6 ~]# ps auxwwf | grep platform coda 68129 0.0 0.0 119400 1352 pts/16 S+ Aug21 0:00 | \_ /bin/csh -f /home/coda/coda/3.10_devel/Linux-x86_64/bin/platform coda 68131 3.2 2.7 8355612 435436 pts/16 Sl+ Aug21 68:44 | \_ /home/coda/coda/jdk1.8.0_152/bin/java -Xms200m -Xmx2048m -Djava.net.preferIPv4Stack=true org.jlab.coda.afecs.platform.APlatform [coda@cdaql6 ~]# kill 68129 68131 [coda@cdaql6 ~]# sudo systemctl start platform.service [coda@cdaql6 ~]# systemctl status platform.service
Scripts.
The hall C philosophy is to call one script at the start of run and call another script at the end of run. These scripts, in turn, call several other scripts. CODA experts familiar with jcedit will realize what the following snapshots mean. Caution! only experts should change things How scripts tied to event builder PEB http://userweb.jlab.org/~rom/hallc/PEB_process.png Process 1 is start_logruninfo.sh and various versions of that like start_logruninfo_nps_coin.sh http://userweb.jlab.org/~rom/hallc/PEB_process1_start_logruninfo.sh.png Process 2 is the end-of-run script http://userweb.jlab.org/~rom/hallc/process2_end_of_run-master.sh.png Look at what's actually in the database, as these things tend to evolve. Experts only.
EDTM Settings
Remotely adjustable EDTM
Currently set with a a command-line helper go_edtm
- There is a command-line helper
go_edtm
to set/readback this PV. (the prescale_GUI does not set it at the moment.) - More details are in this log entry: EDTM pulser switched to cdaqpi1 output
- The RPi that controls this is cdaqpi1 which runs an EPICS softIOC.
F250 Pedestal Updates
Overview
This How-To discusses the necessary steps required in order to take a pedestal run utilizing the single arm DAQ's. Furthermore, the steps required in-order to determine the appropriate FADC thresholds are discussed.
NOTE: This is for EXPERTS ONLY. If this is done poorly and not caught the FADCs will not work correctly and the data maybe garbage!
Taking Pedestal Runs
- Ensure that both single arm DAQ's are configured with the "fadcnothr" flag, which is activated via. of the pre-scale GUI, and the configuration has been saved
- The FADC's can either be in mode 9 or 10
- With both arms take at least 1000 cosmic or EDTM triggers and note the run numbers
Determining the FADC thresholds
- The following example will illustrate the necessary steps required to determine the FADC thresholds for SHMS ROC 2
- On the SHMS side, this procedure will have to be repeated for both ROC's 2 and 4
- On the HMS side, this procedure only has to be executed for ROC 1
- With the pedestal runs complete, open a terminal and SSH into cdaql1
ssh cdaq@cdaql1
- Setup the hallc-online analyzer
go_analysis
- Descend into the hallc-online hcana/podd directory
cd ../hcana/podd/hana_decode/apps
- Exectue the tstfadc_main.C script
./tstfadc
- Input the appropriate configurations: raw data file location, run number, number of events, spectrometer name, crate number
Enter the location of the raw CODA file (raw, raw.copiedtotape): raw Enter a Run Number (-1 to exit): 1537 Enter Number of Events to Analyze (-1 = All): -1 All Events in Run 1537 Will be Analayzed Enter the Spectrometer Name (hms or shms): shms Enter the Crate Number to be Analyzed: 2
- If successful, the for file "fadc_data.root" will have been produced
- In order to produce the threshold text file "thresholds.dat" one needs to execute the calc_thresh_hallc.C ROOT script
root -l ./calc_thresh_hallc.cxx
- Input the appropriate configurations: spectrometer name, crate number, FADC mode, threshold in channels
Enter the Spectrometer Name (hms or shms): shms Enter the Crate Number to be Analyzed: 2 Enter The Mode of The F250's: 9 Enter The Number of Channels Above Baseline the Threshold Should Be [40 (10 mV) recommended]: 40
- A ROOT file "fadc_ped_data.root" will have been created which contains the final fits and determines the baseline values and thus the threshold values which are written to the text file "thresholds.dat"
- Open the "thresholds.dat" file and have a sanity check the thresholds
- Most FADC channels should have thresholds set to 400-700 channels
- For channels set to 4095, these channels are empty
- For ROC2 slot 14 channels 12-15 are set to 1 by default since they are fast raster FADC channels
- For ROC4 slot 18 channels 12-15 are set to 1 by default since they are fast raster FADC channels
- In the event that a few thresholds are set to unrealistic values, simply open the "fadc_ped_data.root" file and perform the fit manually if possible
- If a manual fit is not possible, then a new pedestal run with more statistics is recommended
Loading the FADC Thresholds
- These instructions only pertain to the HMS at the moment. For NPS, it is different.
- In order to have the CRL's load the appropriate FADC threshold files the newly created "thresholds.dat" file must be placed in the correct location
- SSH into cdaql1 as coda
ssh coda@cdaql1
- Descend into the respective thresholds directory for the appropriate ROC
cd coda/config_files/SHMS/ROC02/thresholds
- Copy the newly created "thresholds.dat" into the current working directory and tag the "thresholds.dat" file with the current date
cp hana_decode/thresholds.dat thresholds_DDMONYYYY.dat
- Ascend one directory and symbolically link the newly created thresholds file as "thresholds.dat"
cd ../ ln -fs thresholds/thresholds_DDMONYYYY.dat thresholds.dat