Latest revision as of 18:07, 31 January 2024

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 RCGUI platform cannot connect
5 Live Time Display
6 Setting Prescales
- 6.1 How to pick a prescale value
- 6.2 If the scaler rates in the prescale GUI are not updating
7 Expert notes
8 EDTM Settings
- 8.1 Remotely adjustable EDTM
9 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 cdaql4. 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. (Ask the RC which config to use, but the one that comes up is the last config that successfully ran.)
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 scalers don't count in-between runs

First, decide if you care. One reason to care is if you need to adjust prescales. Scalers do count during a run, or at least I've not seen that fail. Scalers do not count during prestart transition, but that is ok.

If you want to restart scalers (actually the server) wait 2+ minutes after the run and execute the following script, answering "n" (without the quotes) to confirm that you're not doing a run. (We don't want to kill the server during a run.) Any answer differing from a single lower-case "n" is interpreted as "yes" and the script aborts.

[coda@cdaql4 ~]$ /home/coda/bob/checkServer/restartScalerServer

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 cdaql4, so you could login to coda@cdaql4 and type /home/coda/coda/scripts/startVnc, but that's supposed to happen in systemd.)

Further hints on resets

If CODA hangs up

1. Sometimes a simple reset in rcgui fixes it and is the fastest way to restart.  It's the backward-arrow in the rcgui (if you let the mouse hover over the buttons it tells you the name of the button).
2. But if there's a complaint about a VME crate, you may need to power cycle that crate. 
3. Often, even if only one crate complains, one must restart CODA and power-cycle all 8 crates.  This means on coda@cdaql4 : killCoinc ; startCoinc ; and
reboot all the crates (see "reboot a ROC" in this page).

COIN Mode

This should be our production mode for the experiment.

 % ssh coda@cdaql4

In that terminal, run:

 % startCoin

Coda configuration in COIN mode

  coin_sparse : data taking with sparsification on NPS on ( default configuration to use )
  coin : data taking without sparsification on NPS
  coin_vld : LED configuration - make sure to set ps2 to 0
  coin_cosmics : cosmics configuration - make sure to set ps2 to 0 and turn on the cosmics paddles

NPS standalone

(probably not used anymore, see COIN mode above)

 % ssh coda@cdaql4

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. Note that often, even if only one crate complains, one must restart CODA and power-cycle all 8 crates. This means on coda@cdaql4 : killCoinc ; startCoinc in addition to power-cycling.

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. Use the "Main Power" button, not the VME SYSRESET button. 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 cdaql4 (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

RCGUI platform cannot connect

go to expert notes down in this page, and look at how to restart platform instructions

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 [make sure you are using coda@cdaql[1-6]]. 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 might be 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 cdaql4. I think I fixed this, but it's easy to check. Login to coda@cdaql4 and type "ps axw | grep vnc". If it's not running, type /home/coda/coda/scripts/startVnc.

What if cdaql4 goes bad ? We should still be able to run on cdaql6 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 cdaql4; ideally not.

[coda@cdaql4 ~]$  echo $EXPID
NPS

[coda@cdaql4 ~]$  echo $SESSION
NPS

and these are currently "HMS" on cdaql5, which is sometimes used for HMS standalone DAQ. (actually this is deprecated).

"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 cdaql4 and switching between them is just a matter of picking the config in rcgui. There has been a proliferation of configs. Which config are we using ? Ask the RC to be certain. The "HMS"-standalone is compatible with running "NPS"=standalone, which would be a motivation for using it.

PLATFORM ---- PLATFORM ---- PLATFORM ---- PLATFORM

A note about the "platform". The platform is one of the CODA components that runs on the workstation like cdaql4. It is not killed with "killCoinc" because it's been observed that this causes more trouble than it's worth -- maybe because it starts slowly. However, sometimes it is necessary to kill it, especially after many resets it seems to be necessary to kill and restart the platform. To kill it, look in the process list (ps -awx | grep -ai platform) then "kill -9 PID" for the process ID's (PID) corresponding to the platform process (probably more than 1). You don't have to restart the platform by hand anymore. Instead, the platform should be restarted by the systemd. After killing coda, wait for 10 seconds, check platform status by doing: systemctl status platform. You will hopefully see " Active: active (running)". You could also check the process list, as mentioned above. If the platform is active, start coda. If it's not and you don't know the root password, try this "killall coda_platform.sh", and check platform status to see if it's active. Also, note, the platform should run on the same computer (cdaql4 normally) where you are running the rest of CODA, or else the run-start GUI will not pop up. Also, the platform should not run on any other computer, at least not for this $SESSION. In theory the platform would work elsewhere, but it makes in harder to find it for shift workers (because they may need to kill it), plus the issue of the start-run pop-up.

Ole Hansen enabled sudo access for the cdaq and coda accounts on cdaql4 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@cdaql4 ~]# 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@cdaql4 ~]# kill 68129 68131

[coda@cdaql4 ~]# sudo systemctl start platform.service

[coda@cdaql4 ~]# systemctl status platform.service

If you don't know the root password, try the following to restart platform:

killall coda_platform.sh

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.

MSS copying script. All the "action" is on coda@cdaql4. It's a cron job on the coda account, type "crontab -l" to see. The main script we care about for moving data to MSS and deleting from disk is: /home/coda/coda/jmirror_scripts/hallc_jmirror. This is a lot like the setup in hall A. Yes, I did change Brad's scheme to 100% use jmirror.

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

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