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Running DAQ Interface » History » Version 203

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Erik Blaufuss, 01/06/2016 01:49 PM


Getting help

If, after reading this document (in particular, the "Troubleshooting and FAQ" section) you run into issues, or have questions, please contact:

Logbook

Please document all changes, software updates, and operational activities to the ELog:

http://dbweb3.fnal.gov:8080/ECL/lbne_35t

Brief preliminaries

Everything in this wiki was up-to-date as of October 11, 2015.

This guide assumes you have access to the lbnedaq account on the LBNE 35 ton gateway node, lbne35t-gateway01.fnal.gov . It also assumes you have a rudimentary knowledge of how to navigate a bash environment in Linux (how to change directories, log onto different machines, perform time-ordered listings of files, edit a file using emacs or vi, etc.).

The installed code is located at lbne35t-gateway01.fnal.gov:/data/lbnedaq/daqarea/lbnerc. If you need access to the lbnedaq lbne35t-gateway01.fnal.gov account, please contact one of the people listed above under "Getting Help". Once you have access, to get started, login (ssh -l lbnedaq lbne35t-gateway01.fnal.gov) and first setup the environment:

cd /data/lbnedaq/daqarea
source fireup

This will take you into the /data/lbnedaq/daqarea/lbnerc directory, out of which the DAQ is controlled. For the remainder of this wiki, the assumption is that you've already setup the environment using the above commands.

Keep in mind that you shouldn't run the DAQ if someone else is using it. To figure out whether this is the case, see "Getting the status", further down this document. Also keep in mind that when you use the DAQ, you should make a note of it in the elog, along with how long you plan to use it and whether you're willing to let someone else step in if your work is non-urgent. A reminder to this effect is printed whenever you log into lbne35t-gateway01.fnal.gov.

To see the terminal output of RunControl and DAQInterface, you'll want to be in the same terminal from where they were launched. This means it's typically not a good idea to try to use a "stale" RunControl and/or DAQInterface that someone else may have started hours (or even days) ago.

Concerning example output shown in this document: when you see an ellipse ("…"), that is to be interpreted as a placeholder for output which is considered irrelevant to the point being explained.

Killing, launching, and getting the status of the DAQ applications

The DAQ application suite consists of RunControl, the configuration manager, DAQInterface (the component which intermediates between RunControl, the configuration manager, and the artdaq processes) and the XML-RPC server for the TDU (the program which allows a sync pulse to be sent to the hardware at the start of DAQ running). The following points about these programs should be observed:
  • These applications all need to be running in order for the DAQ to work
  • DAQInterface needs to be launched after RunControl
  • The actual names of the processes are "lbnecontrol" (RunControl), "daqinterface" (DAQInterface), "CfgMgrApp" (the configuration manager) and "tdu" (the TDU XML-RPC server)

Getting the status

In order to determine which DAQ applications are already active, two approaches can be taken, depending on whether or not RunControl is itself active. If it isn't, you'll need to enter the following:

check_daq_applications.sh

which will produce output which looks like this:

lbnecontrol: **Not Found**
CfgMgr: Available
DAQInterface: Available
TDUControl: **Not Found**

Most recent DAQ logfile written (current US Central Time is Apr 10 09:56):
Apr 8 17:25 /data/lbnedaq/daqlogs/pmt/pmt-32342.1-20150408171225.log

In other words, the above command will both tell you which, if any, of the four primary DAQ applications are running, and then tell you the time of the most recently modified logfile; this last piece of information is helpful in determining whether the DAQ is currently in active use by another individual. In particular, you see that the configuration manager and DAQInterface already exist, but RunControl and the TDU's XML-RPC server do not. In this case, you would not only want to launch RunControl and the server, but you would also want to kill and relaunch DAQInterface. Unless someone had just posted in the elog that they were planning to run on the DAQ (and did so before you had a chance to post!), you wouldn't need to worry about interfering with someone else's DAQ work, since you can see above that it's been almost two days since any DAQ output was logged.

Another way of checking which applications are alive is through "lbnecmd check"; note this command will only work if RunControl (lbnecontrol) is itself alive:

lbnecmd check

You'll then see output similar to that of check_daq_applications.sh as far as which applications are alive; however, it contains additional information not shown which will be discussed later:

lbnecontrol: Available
CfgMgr: **Not Found**
DAQInterface: Available
TDUControl: **Not Found**
...

Be aware that if you attempt "lbnecmd check" when RunControl is not yet available, you'll simply see "check failed: '[Errno 111] Connection refused'. Is lbnecontrol running?".

Cleanup: killing DAQInterface, the configuration manager, and the TDU XMLRPC server

As of March 30, 2015, a new script called "kill_daq_applications.sh" can be run at the command line to kill the DAQ applications. It's capable of killing all the major applications except for RunControl, which is meant to always be running. In order to kill the other three applications, one would run:

kill_daq_applications.sh -c -d -t

where each option corresponds to the killing of a particular application: "-c" for the configuration manager, "-d" for DAQInterface, and "-t" for the TDU XML-RPC server. If only a subset of these three applications are running, then only use the relevant options (e.g., simply run "kill_daq_applications.sh -t" if the only application running is the TDU server). Running the script without any options at all will print out instructions similar to what you see here. Be aware that it's good etiquette to make sure someone's not currently using the DAQ before you start killing applications.

Note that as of Dec-22-2015, killing DAQInterface will also kill the auto_file_close.sh script, but not kill the MessageViewer application.

For the previous instructions for killing the applications (still correct, though more work-intensive, but includes the expert-only instructions on how to kill RunControl), click on "Show", below:

Launching RunControl, DAQInterface, the configuration manager, and the TDU XMLRPC server

Also as of March 30, 2015, a new script called "launch_daq_applications.sh" can be run at the command line to launch the DAQ applications. In order to launch all four applications, one would run:

launch_daq_applications.sh -c -t -r -d <daqinterface configuration file>

where unless you have your own working copy of the DAQInterface configuration file (what this is will be described later in this wiki), "<daqinterface configuration file>" should be "docs/config.txt". The options refer to the same applications as in the case of kill_daq_applications.sh, and like kill_daq_applications.sh, executing the script without any options will print out instructions. Be aware, however, that DAQInterface will not be launched if RunControl isn't already running. In practice, though, you can launch RunControl in the same launch_daq_applications.sh command by preceding the DAQInterface option with the RunControl option -- so, if the configuration manager and the TDU server are already up and available, then one would only need to execute "launch_daq_applications.sh -r -d <daqinterface configuration file>" in order to have the full suite of DAQ applications available for use.

Note that if an application of a given type is already running, launch_daq_applications.sh will not launch a duplicate application, but will instead print a warning to the screen.

Note also that when you launch DAQInterface, a window with the header "MessageFacility MsgViewer" will pop up; it's in this window that messages about the running DAQ (color coded by severity level) will appear. More on this in a bit.

Another program that launches along with DAQInterface is called "auto_file_close.sh"; this is a script which will issue automatic stop-start transitions to the DAQ when diskwriting runs are performed, such that on stop the current output file is closed and the run is ended, and on start the run number increments and a new file is opened. The frequency with which this occurs can be set in the DAQInterface configuration file (see below for more on this file); as of Dec-22-2015 the current default is for the stop-start to be issued either after ten minutes since the start of the run or after a file has reached 5 gigabytes.

For the previous instructions on how to launch the DAQ applications (still correct, but more detailed and labor-demanding), click on "Show" below:

Note: Run Control is generally not stopped and started by launch_daq_applications.sh any longer. The main Run control server should be running all the time to support Slow Control reported information. If you suspect issues with Run Control, see the TroubleShooting and FAQ section below for help.

Performing a Run

With the applications launched, you can take the DAQ system through the standard transitions to perform a DAQ run. The "ground state" of the DAQ is called the "stopped" state. Each successful transition brings the DAQ into a different state. Described in more detail later, the chain of states (in quotes) and transitions (in italics) in the DAQ system can be represented as follows:


"stopped" -> init -> "ready" -> start -> "running" -> pause -> "paused" -> resume -> "running" -> stop -> "ready" -> terminate -> "stopped"


Checking the state of the DAQ

At all stages, you can use the "lbnecmd check" command to see what state DAQInterface is in; example output of this is as follows:

lbnecontrol: Available
CfgMgr: Available
DAQInterface: Available
TDUControl: Available

Run number: 797
Run configuration: ganglia_test
Run type: Test
daqint@localhost:5570 (synchronous): running

Here, you've already seen how lbnecmd check can tell you whether a given application type has been launched or not; on the bottom line, however, you'll also see a description of the state of the DAQ -- in this case, "running", meaning that it's actively acquiring data.

Note that you'll want to wait for a transition to complete before issuing another one, otherwise you'll receive a warning and the transition request will be ignored. DAQInterface will also report when transitions are complete -- e.g., at the end of the "initialize" transition, you'd see:

Initialize transition complete; if running DAQInterface in the background, can press <enter> to return to shell prompt

If a high "debug level" has been set for DAQInterface (see below for more on this), this message can get buried in a set of output messages; in this case "lbnecmd check" may be the easiest way to determine what state the system is in.

Selecting a run configuration and DAQ components

Before initializing or starting a DAQ run, a configuration and set of DAQ components must be selected. This is done via RunControl.

List and select a configuration:

To see the list of available configurations (queried from the configuration manager):

lbnecmd listconfigs

This lists all available configs, as well as the current selected config (Note, default config is "No Config"):
Available configs (Name : description)

rces_and_ssps : Run up to 8 SSPs and 4 RCEs, with ganglia, online monitoring, and root file output enabled

demo_rc_reporter : A version of the demo which reports metrics to RunControl

demo : This is a demo.  Testing 1, 2, 3…
...

Current selected config: No Config

You can then select a configuration -- for the purposes of this tutorial, let's go with "demo", which creates simulated data without using any hardware:
 
lbnecmd setconfig demo

This will return "OK" if successful; "lbnecmd listconfigs" will then show this as the current config via its last line of output: Current selected config: demo. If the specified configuration is not known, an error is returned. Instructions on how to add or edit a configuration (an expert-only action) are given later in this document.

Note: when taking data with the machine, you'll most likely be using the "rces_and_ssps" configuration; this allows you to connect to the SSPs, RCEs and Penn trigger board, runs the online monitoring module, and saves the output data in *.root files.

List and select DAQ components.

You can select which portions of the LBNE DAQ setup you want to use in the upcoming run. These are mapped generally to the artdaq BoardReaderMain processes
that read them out. As an operator, you need to ensure that there are configuration files available in the configuration manager for the DAQ Components that you select here, or DAQInterface will return an error- so, for example, if you're using the "demo" configuration, you couldn't request ssp01 as one of the components, since the demo configuration only allows for components which create simulated (i.e., fake) data.

To see the list of available DAQ components:

lbnecmd listdaqcomps

Will return a list of components available and selected (Default is ALL available components), e.g.:
Available:
component01 (lbnedaq2:5205)
component02 (lbnedaq2:5206)
…
ssp08 (lbnedaq1:5214)

Selected:
component01 (lbnedaq2:5205)
component02 (lbnedaq2:5206)
…
ssp08 (lbnedaq1:5214)

The components are shown by name, along with the requested host/port to run the component's corresponding BoardReaderMain process on. You can then select a list of DAQ components to use in the run:
lbnecmd setdaqcomps component0{1,2}

(n.b. the {1,2} in brackets is a Linux bash shell trick which expands component0{1,2} to component01 component02). This will return "OK" if successful ("lbnecmd listdaqcomps" will show this in the "selected" set of components). If the specified components are not known, an error is returned.

How to make a new component available to RunControl is described later in this document.

Initializing, starting, stopping and terminating a Run

For each of these transitions, please recall that while "lbnecmd <cmd>" returns very quickly, the actual issued command can take several seconds or minutes to complete. Before issuing another command, be sure that the transition is complete by using the check command:

lbnecmd check

For example, before issuing the "start" transition, you can use this command to ensure that the DAQ is in the "ready" state and not still in the "initializing" stage.

First, take DAQInterface from the "stopped" to the "ready" state; this will create the artdaq processes on the hosts they've been assigned, and initialize them with the FHiCL documents:

lbnecmd init daq

You'll see the MessageFacility MsgViewer window fill with a few messages; it'll look something like this:

You'll be able to filter out messages by level of severity; so, for example, if you only cared about Error messages you could click on "Error" in the upper-right hand corner of the window. To reinstate the display of Error, Warning and Info messages, you could click on "Info". In general, allowing for these three types of message is probably a good default. Note that developer decisions about what messages constitute Error vs. Warning vs. Info are still evolving as of Oct 10, 2015, and will likely be influenced by the first couple of weeks of running.

Now, in order to begin taking data, take DAQInterface from the "ready" to the "running" state:

lbnecmd start daq

Immediately, you'll see a request for a confirmation that the configuration and selected components are in fact the ones you want; it will look something like the following:
DAQ config
**********
Run Type: Test
Selected config: demo
Selected DAQ components:
   component01 (lbnedaq1:5205)
   component02 (lbnedaq1:5206)
Start DAQ with these settings? [y]|n: 

Assuming you're happy with the configuration and components, hit "y" to proceed, and as with the other transitions, wait for the "transition complete" message to appear.

Note that the current run number is displayed when DAQ is in the running state using the "lbnecmd check" command. If the start transition was successful, information about the run is saved in the run records directory, /data/lbnedaq/run_records/<run_number>, where <run_number> is to be taken as a stand-in for the actual run number. More on how to understand the directory's contents is described below, under "Examining the output".

Pause the running of the DAQ, putting DAQInterface into the "paused" state. This will cause the current open output Root file to be closed and given a name reflecting the current run and subrun numbers (the format as of October 10, 2015 is lbne_r<run number>_sr<subrun number>_<creation time>.root; the file appears in /storage/data on lbnedaq6):

lbnecmd pause daq

Resume the running of the DAQ, returning it to the "running" state. This will restart data taking to a new output file:

lbnecmd resume daq

Halt the running of the DAQ, returning DAQInterface to the "ready" state from the "running" state:

lbnecmd stop daq

From the ready state, you can start a new run with the same configuration and DAQ components you originally selected.
NOTE To select a new configuration or DAQ component set, you must issue the "terminate" command, which will kill all ArtDAQ processes and return DAQInterface to its "stopped" state:

lbnecmd terminate daq

Examining the output

Once you've completed your run, there are typically two primary outputs: the Root files which contain the data which passed through the DAQ (saved, as of October 10, 2015, in /storage/data on lbnedaq6), and a set of text files containing information about the run. To access these text files, you'll want to go to the run records directory, which defaults to /data/lbnedaq/run_records/<run_number>. This directory contains the FHiCL documents used to control the ArtDAQ processes in the run, the DAQInterface configuration file used (described later in this wiki), and a metadata file, which, among other things, describes where to find a record of the DAQ's output. An example of this file, for run 778, can be found if we look in /data/lbnedaq/run_records/778 at "metadata_r778.txt":

Config name: demo
Component #0: component01
Component #1: component02
lbne-artdaq commit: 0f0f9be1c63a3b487170579c887ce79944eca6f8
lbnerc commit: 92935f2702c5e0aa732fd3cc9ff6758e1a0c288c
/data/lbnedaq/config/ commit: 97d8b222742a41d5d10ea942a063ddfacac3ce93

pmt logfile(s): lbnedaq3:/data/lbnedaq/daqlogs/pmt/pmt-25771*.log

boardreader logfiles: 
lbnedaq3:/data/lbnedaq/daqlogs/boardreader/boardreader-20150320163004-lbnedaq2-37365.log
lbnedaq3:/data/lbnedaq/daqlogs/boardreader/boardreader-20150320163004-lbnedaq2-37366.log

eventbuilder logfiles: 
lbnedaq3:/data/lbnedaq/daqlogs/eventbuilder/eventbuilder-20150320163004-lbnedaq2-37364.log
lbnedaq3:/data/lbnedaq/daqlogs/eventbuilder/eventbuilder-20150320163004-lbnedaq2-37363.log
lbnedaq3:/data/lbnedaq/daqlogs/eventbuilder/eventbuilder-20150320163004-lbnedaq2-37368.log

aggregator logfiles: 
lbnedaq3:/data/lbnedaq/daqlogs/aggregator/aggregator-20150320163004-lbnedaq2-37369.log
lbnedaq3:/data/lbnedaq/daqlogs/aggregator/aggregator-20150320163004-lbnedaq2-37367.log


The most significant things saved in this file for the end user of the DAQ system are the configuration chosen and the components chosen for the run (at the top of the file), and the wildcard for the pmt (ArtDAQ Process Management Tool) logfiles, which contain the output of the DAQ system, under "pmt logfile(s)" -- so, in this case, executing ls -ltr /data/lbnedaq/daqlogs/pmt/pmt-25771*.log would list the files containing the output of the DAQ in run 778. Concerning this last point, just be aware of the possibility that earlier DAQ sessions may have produced logfiles which also satisfy the wildcard, as the "25771" in the wildcard example provided refer to the process ID of the pmt process, which isn't necessarily unique for a given run.

The DAQInterface configuration file

DAQInterface uses some key information stored in a local configuration file, NOT to be confused with the run configuration described elsewhere on this wiki. It's expected that for normal operations, most parameters should not need to changed too often, and alterations will be primarily of developer or expert interest. If you ARE a developer/expert or are simply curious,

Editing or adding RunControl configurations

Adding new DAQ Components to RunControl

Troubleshooting and FAQ

Common RunControl issues

How can I get a list of all RunControl commands?

lbnecmd help

will list all available commands for RunControl with some details for help.

It seems that "lbnecmd" is not responding properly

If the primary run control server process (called lbnecontrol) is not running, or has gotten into an unresponsive state (often characterized by RPC timeouts), you might have to start/restart the main run control process.

To check the health of Run Control, try:

lbnecmd check

Normal output will look like:
(env)[lbnedaq@lbne35t-gateway01 daqarea]$ lbnecmd check
lbnecontrol: Available
CfgMgr: Available
DAQInterface: Available
TDUControl: Available

daqint@localhost:5570 (synchronous): stopped

If you see errors such as:
(env)[lbnedaq@lbne35t-gateway01 lbnerc]$ lbnecmd check 
check failed: 'timed out'. Is lbnecontrol running? 

or
(env)[lbnedaq@lbne35t-gateway01 lbnerc]$ lbnecmd check 
check failed: '[Errno 111] Connection refused'.  Is lbnecontrol running?

You'll need to restart/start the lbnecontrol server. First make sure it's stopped:
> lbnecmd kill

Then start it:
> lbnecmd launch

If you run into errors like:
> lbnecmd launch
Control program is running or stale process file (/tmp/lbnecontrol.pid) exists!

Make sure the lbnecontrol process is dead.
> ps -ef |grep lbnecontrol |grep -v grep

If it's still there, you can kill it (kill <PID>), then remove the lock file and restart lbnecontrol:
> rm /tmp//tmp/lbnecontrol.pid
> lbnecmd launch

No real configurations are listed by RunControl

If you run "lbnecmd listconfigs" and see something like:

Available configs (Name : description)

dummy : Dummy description

Instead of your expected configurations, RunControl is not able to connect to CfgMgr. Please make sure it's running; how to do this, described earlier in the wiki, is simply to execute "lbnecmd check", and launching the configuration manager, also described earlier, can be done via "launch_daq_applications.sh -c"

"lbnecmd check" returns "Unknown exception '<ProtocolError for localhost:50008/RPC2: -1 >'"

This sometimes happens when the TDU XML-RPC server has died. You can confirm this has happened by running "check_daq_applications.sh"; to relaunch it, run "launch_daq_applications.sh -t".

Common DAQInterface issues

As a preliminary: if something goes wrong when running the DAQ, there are two valuable sources of information:
  1. The pmt logfile(s), containing the output of the artdaq processes (including the output of the art modules run within them -- so, for example, an exception throw from within a module would appear here). Where to find these logfiles is described in the section "Examining your output", earlier in this wiki.
  2. The RunControl logfile, /home/lbnedaq/.lbnerc.log . This contains both the information sent from DAQInterface to RunControl, as well as diagnostic logging (such as the traceback of exception throws within DAQInterface)

In general, when something goes wrong during the running of the DAQ -- e.g., an artdaq process dies, or a sync pulse is attempted when the TDU XML-RPC server isn't alive -- DAQInterface will impose upon itself the "recovery" transition, where it returns itself to the "stopped" state regardless of whatever state it may have currently been in. When this occurs, you'll see something like the following:

DAQInterface: "Recover" transition underway
JCF, 6/12/14 -- for now at least, "Recover" simply kills the artdaq processes

Recover transition complete; if running DAQInterface in the background, can press <enter> to return to shell prompt

If a recovery transition occurs, often you can begin using the DAQ again (starting with "lbnecmd init daq") without any issues. However, some issues may be persistent, or require manual intervention. A subset of those issues are described below. If any new ones come up, please contact John Freeman at .

Whenever you try to initialize, right after initialization DAQInterface immediately enters recovery mode

Specifically, you'll see something like the following:

Fri Nov 20 18:16:32 CST 2015: Initialize transition complete; if running DAQInterface in the background, can press <enter> to return to shell prompt

Fri Nov 20 18:16:33 CST 2015: DAQInterface: "Recover" transition underway
JCF, 6/12/14 -- for now at least, "Recover" simply kills the artdaq processes
JCF, 10/21/15 -- have now added an attempted stop transition

Fri Nov 20 18:16:50 CST 2015: Recover transition complete; if running DAQInterface in the background, can press <enter> to return to shell prompt

This happens because on a previous run, DAQInterface threw an exception. As of Nov-20-2015, the most common cause of this is that it was unable to send a requested transition to an artdaq process because the process wasn't responding- a very common cause of this is a buildup of incomplete events in the eventbuilders. The only thing to do here is to kill and relaunch DAQInterface.

On the initialize transition ("lbnecmd init daq") you see "Unclean working configuration directory /data/lbnedaq/config/ found"

This means that the subdirectory of /data/lbnedaq/config corresponding to the active configuration has been edited without commits being made. If you're not using the generic DAQInterface configuration file "config.txt", but rather, have your own copy, you can set "disable configuration check: true" to sidestep this error. This is NOT recommended during standard physics running, but is OK if you're in commissioning. Or, you can either commit the changes (if they were yours) or contact John Freeman, , describing the situation.

On the initialize transition, you see "pmt.rb -p <port number> was already running on <hostname>"

An instance of artdaq's Process Management Tool program, tasked with creating the artdaq processes, is already running on the host and port you've requested for it in the DAQInterface configuration file passed to the DAQInterface application. This can happen if, for example, the DAQInterface program from a previous session was killed off before the usual "lbnecmd terminate daq" transition was issued, a transition which prompts DAQInterface to kill off the pmt.rb process it has control over. Generally, DAQInterface will clean this up and free the port in the process of returning itself to the "stopped" state, but in case it doesn't, there's a script called "kill_artdaq_processes.sh" which can be used in the following manner:

kill_artdaq_processes.sh <pmt host> <pmt port>

This script will both kill off the pmt.rb which is clogging the port, as well as the artdaq processes over which it has control.

On the initialize transition ("lbnecmd init daq"), you see "error: [Errno 111] Connection refused"

If a "Recover" is triggered and you can see via "lbnecmd check" that DAQInterface is in the "stopped" state, try initializing again. If that doesn't work, you can try increasing the value of the "pause before initialization" variable in the DAQInterface configuration file. Empirically, it appears there needs to be a pause of at least 5 seconds before the FHiCL documents can be successfully sent via XML-RPC to the processes; increasing this value may make it less likely that the "Connection refused" error occurs.

On the start transition ("lbnecmd start daq"), you see "TDU RESULT: socket.error caught: [Errno 111] Connection refused Is the XMLRPC server up?"

This error will trigger the Recover transition and return you to the stopped state. What it means is that there was an issue connecting to the TDU XML-RPC server (most likely, it wasn't running). Run "lbnecmd check" to see whether it's available; if not, launch it in the usual fashion (i.e., "launch_daq_applications.sh -t"), and then proceed with the standard DAQ transition sequence ("lbnecmd init daq", etc.)

Regardless of how high the debug level is set to, you don't see any output to screen when you issue transitions to DAQInterface

Chances are that DAQInterface was started in another terminal, and consequently, it's in that terminal where output will appear. If DAQInterface was started via the "launch_daq_applications.sh" script, then as of May-5-2015, all output is directed to /data/lbnedaq/daqlogs/daqinterface/DI.log, so running "tail -f /data/lbnedaq/daqlogs/daqinterface/DI.log" from another terminal will guarantee you can see DAQInterface output in real time. Please note this file is appended to, not overwritten, so only the end of the file will be of interest.

Common lbne-artdaq issues

The message "Failed to connect to shared memory segment" appears in the logfile

The full message is "Failed to connect to shared memory segment, errno = 22. Please check if a stale shared memory segment needs to be cleaned up. (ipcs, ipcrm -m <segId>)". Go to the system on which the process that issued the message is running (e.g., if it was an AggregatorMain process on lbnedaq2, go there) and run ipcs. You should see something like the following:

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status      
0x40471518 4161536    lbnedaq    666        16777216   0          

This is the offending memory segment. To remove it, run the following (where here, we'll assume it's the one with shared memory ID 4161536, above-- of course you'll most likely see a different ID): ipcrm -m 4161536. Now, if you run ipcs again, the segment should not be listed; furthermore, the error should not appear again if you run again with the DAQ.

The message "An exception occurred when trying to send a message to 131.225.177.29:30000" appears in the logfile

Port 30000 is the port on which MessageFacility MessageViewer communicates; this above message appears if the MessageViewer window has been closed, and the DAQ is trying to send a message to MessageViewer. It's not a concern from a practical standpoint- it simply means that DAQInterface should be killed and restarted in order to pop up a new MessageViewer window.