The following error has been reported to me by T2K colleagues:

When using  "odbedit -c "msg my_message", the following behavior 
has been observed depending on the length "n" of the message. 

1)  n < 100        All is well
2)  100 <= n < 245 Log not written but exit code = 0
3)  245 <= n < 280 Error: "Experiment not defined" and exit code = 1
4)  280 <= n       Error: "Cannot connect to remote host" and exit code = 1

Also, when logging from compiled C code - when messages reach some magic length
the MIDAS client sending them segfaults.

Please fix

> The following error has been reported to me by T2K colleagues:
> 
> When using  "odbedit -c "msg my_message", the following behavior 
> has been observed depending on the length "n" of the message. 
> 
> 1)  n < 100        All is well
> 2)  100 <= n < 245 Log not written but exit code = 0
> 3)  245 <= n < 280 Error: "Experiment not defined" and exit code = 1
> 4)  280 <= n       Error: "Cannot connect to remote host" and exit code = 1
> 
> Also, when logging from compiled C code - when messages reach some magic length
> the MIDAS client sending them segfaults.
> 
> Please fix

Uhhh, who wants this long messages? You should consider to split this into several 
smaller messages. Anyhow, having the above behavior is not good, so I fixed it in 
SVN revision 4422. I increased the maximum length to 1000 characters. Above that, 
the message gets truncated. If you need even more, we can make it a #define.

The second problem you describe (logging from compiled C code) I could not 
reproduce, so maybe it was related to the first one. Please try again and report 
if it persists.

Dear Midas Experts

I am Wenliang Li, a graduate student from University of Regina. Our group have
encountered some difficulty on outputting ADC and TDC data into ROOT tree with
the MIDAS SVN Revision: 5347.

Our Linux Distribution: Scientific Linux release 6.0 (Carbon)
ROOT Version:           ROOT 5.28
gcc version:            g++ (GCC) 4.4.4 20100726 (Red Hat 4.4.4-13)
kernel version:         2.6.32-279.19.1.el6.i686


I am using the given example $MIDASSYS/examples/experiment to generate some
data, and the issue is that the analyzer refuses to turn on the  ADC0 and TDC0
back switches. 

If the ADC and TDC banks are switched off, the analyzer will successfully output
the histograms but not the ROOT tree, and the Trigger and Scaler root trees are
completely empty.

With the same example experiment: $MIDASSYS/examples/experiment, this issue does
not occur on MIDAS SVN Revision: 4309.


The output error messages in the analyzer window are shown if the ADC and TDC
banks are switched to 1:

*************************
Connect to experiment ...OK
Root server listening on port 9090...
Loading previous online histos from /home/billlee/experiment/test_exp/last.root
Running analyzer online. Stop with "!"
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
ROOT TTree rebooked
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
Error in <TTree::Branch>: The pointer specified for TDC0 is not of a class known
to ROOT and (null) is not a known class
ROOT TTree rebooked
***********************
***************************



If I analyze the data with TDC and ADC bank switched set to be 1 :
$ analyzer -i runXXXXX.mid -o runXXXXX.root

I get the following error messages:


************************************************************************
************************************************************************


Root server listening on port 9090...
Running analyzer offline. Stop with "!"
Error in <TTree::Branch>: The pointer specified for ADC0 is not of a class known
to ROOT and (null) is not a known class
Error in <TTree::Branch>: The pointer specified for TDC0 is not of a class known
to ROOT and (null) is not a known class
Set run number 1 in ODB
Load ODB from run 1...OK

 *** Break *** segmentation violation



===========================================================
There was a crash.
This is the entire stack trace of all threads:
===========================================================

Thread 2 (Thread 0x7f46c6853700 (LWP 10808)):
#0  0x0000003b63a0e84d in accept () from /lib64/libpthread.so.0
#1  0x0000003b64e370f4 in TUnixSystem::AcceptConnection(int) () from
/usr/lib64/root/libCore.so.5.28
#2  0x0000003b6647849c in TServerSocket::Accept(unsigned char) () from
/usr/lib64/root/libNet.so.5.28
#3  0x000000000040c50e in root_socket_server (arg=<value optimized out>) at
src/mana.c:5275
#4  0x00007f46c8dc513a in TThread::Function(void*) () from
/usr/lib64/root/libThread.so.5.28
#5  0x0000003b63a07851 in start_thread () from /lib64/libpthread.so.0
#6  0x0000003b62ee811d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f46c8b94720 (LWP 10800)):
#0  0x0000003b62eabfdd in waitpid () from /lib64/libc.so.6
#1  0x0000003b62e3e899 in do_system () from /lib64/libc.so.6
#2  0x0000003b62e3ebd0 in system () from /lib64/libc.so.6
#3  0x0000003b64e3da31 in TUnixSystem::StackTrace() () from
/usr/lib64/root/libCore.so.5.28
#4  0x0000003b64e3d3f3 in TUnixSystem::DispatchSignals(ESignals) () from
/usr/lib64/root/libCore.so.5.28
#5  <signal handler called>
#6  0x000000000041245f in TIter (file=<value optimized out>,
pevent=0x7f46c5281010, par=0x665180) at /usr/include/root/TCollection.h:148
#7  write_event_ttree (file=<value optimized out>, pevent=0x7f46c5281010,
par=0x665180) at src/mana.c:2872
#8  0x0000000000412a4c in process_event (par=0x665180, pevent=0x7f46c5281010) at
src/mana.c:3195
#9  0x0000000000412e42 in analyze_run (run_number=1,
input_file_name=0x7fff4d738340 "run00001.mid", output_file_name=<value optimized
out>) at src/mana.c:4178
#10 0x0000000000413372 in loop_runs_offline () at src/mana.c:4366
#11 0x0000000000413ba5 in main (argc=<value optimized out>, argv=<value
optimized out>) at src/mana.c:5579
===========================================================


The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
http://root.cern.ch/bugs. Please post the ENTIRE stack trace
from above as an attachment in addition to anything else
that might help us fixing this issue.
===========================================================
#6  0x000000000041245f in TIter (file=<value optimized out>,
pevent=0x7f46c5281010, par=0x665180) at /usr/include/root/TCollection.h:148
#7  write_event_ttree (file=<value optimized out>, pevent=0x7f46c5281010,
par=0x665180) at src/mana.c:2872
#8  0x0000000000412a4c in process_event (par=0x665180, pevent=0x7f46c5281010) at
src/mana.c:3195
#9  0x0000000000412e42 in analyze_run (run_number=1,
input_file_name=0x7fff4d738340 "run00001.mid", output_file_name=<value optimized
out>) at src/mana.c:4178
#10 0x0000000000413372 in loop_runs_offline () at src/mana.c:4366
#11 0x0000000000413ba5 in main (argc=<value optimized out>, argv=<value
optimized out>) at src/mana.c:5579
===========================================================


[midas.c:1973:,ERROR] cm_disconnect_experiment not called at end of program

**********************************************************************************************
**********************************************************************************************







I wonder if there is any program syntax change between MIDAS Version 4309 and
5347, and are there any simple working setup example which can output root tree
with the newest version of MIDAS?
 
In the end, I would like to thank the continuous effort from Triumf and PSI on
developing MIDAS, it is a pleasure to work with.

Many thanks
Bill 

Dear Bill,

the Midas analyzer "mana.c" is currently not maintained. At PSI we use the ROME framework (which might be too complicated for a 
small experiment) and at TRIUMF the ROOTANA framework is used:

http://ladd00.triumf.ca/~olchansk/rootana/

You might be better off switching to that one.

Best regards,
Stefan

1) Prior upgrading midas to 1.9.3, make sure you've saved your ODB in ASCII
   format using "odbedit> save my_odb.odb", as the internal structure is
   incompatible with previous version. You will be able to restore it once
   the new odb is up using "odbedit> load my_odb.odb".

2) since version 1.9.2, the analyzer supports ROOT and PAW packages.
   The general Midas makefile build the analyzer core system mana.c
   differently depending on presence of the environment variable $ROOTSYS.

   In the case $ROOTSYS is not defined, the Makefile will create:
   ~/os/lib/mana.o, build for NO HBOOK calls.
   ~/os/lib/hmana.o, build with HBOOK calls for PAW analyzer
    (requires /cern/pro/lib to be present).

   In the case $ROOTSYS is defined and pointing to a valid root directory:
   ~/os/lib/mana.o, build for NO HBOOK calls.
   ~/os/lib/rmana.o, build for ROOT analyzer.

3) Since 1.9.2, the ~/examples/experiment contains the ROOT
   analyzer example instead of HBOOK. The local Makefile uses the source
   examples and the ~/os/lib/rmana.o for building the final user
   application.
   
   The previous HBOOK(PAW) analyzer has been moved into ~examples/hbookexpt
   directory. The analyzer is build using the ~/os/lib/hmana.o 

4) A new application "rmidas" is available when the system is build with
   ROOT support. This application is an initial "pure" ROOT GUI implementing
   TSocket for remote ROOT histogram display. 
   Once a ONLINE ROOT analyzer is up and running, by invoking "rmidas"
   you will be prompt for a host name. Enter the node name hosting the
   analyzer. You will be presented with a list of histogram which can
   be display in a ROOT frame environment (see attachment). 

5) The support of ROOT is also available for the logger by changing  
   the data format and the destination file name in the ODB structure.
   This option will save on file the Midas banks converted into ROOT Tree.
   This file can be opened with ROOT (see attachment).

------- ODB structure of /Logger/Channels/0/Settings
   [local:midas:R]Settings>ls
    Active                          y
    Type                            Disk
    Filename                        run%05d.root    <<<<<<<<< new extension
    Format                          ROOT            <<<<<<<<< new format
    Compression                     0
    ODB dump                        y
    Log messages                    0
    Buffer                          SYSTEM
    Event ID                        -1
    Trigger mask                    -1
    Event limit                     0
    Byte limit                      0
    Tape capacity                   0
    Subdir format                   
    Current filename                run00211.root
-------   

.

    for (INT i = 0; i < hv_info->num_channels; i++) {
      char element[HKEY_STRING_LENGTH];
      snprintf(element, HKEY_STRING_LENGTH, "%s[%d]", path, i);
      if (db_find_key(hDB, hv_info->hKeyRoot, element, &hKey) == DB_SUCCESS) {
        if ((hv_info->driver[i]->flags & flag) == 0) 
          db_open_record(hDB, hKey, &array[i], sizeof(double), MODE_READ, callback, pequipment);
        else
          db_open_record(hDB, hKey, &array[i], sizeof(double), MODE_READ, NULL, NULL);
      } else {
        cm_msg(MERROR, __func__, "Key %s not found", element);
      }
    }

> Is it possible to open a hotlink to a single element in an ODB array?

Not possible.

> sprintf(element, "%s[%d]", path, i);
> db_find_key(hDB, hv_info->hKeyRoot, element, &hKey);

There is some confusion and inconsistency between db_xxx() functions,
some of them accept the array index "a[10]" syntax, some do not.

db_find_key() and db_watch()/db_open_record() do not operate on array elements
and do not accept the "a[10]" array index syntax.

K.O.

> I will try to use the db_watch function in the future.

Note that db_watch() and db_open_record() work exactly the same way, both only allow 
watching "whole" odb entries, you cannot watch individual array elements.

The db_watch() callback function gives you the array index of the array element that was 
changed and that fired the notification. 

*but*

If you change many array elements quickly you will not necessary receive notifications for 
all and each of of them (underlying transport is UDP allows notification packet loss).

If you are watching 1 array element change at a slow rate (1/sec), db_watch() will work well.

Otherwise, you can watch the whole array, in the db_watch() callback, read the new array 
contents, compare it with your saved copy of pervious array contents, identify which array 
elements have changed and dance from here. (this method does not work if you do not 
actually change the array element values: change from "1" to "1", this is an old weakness in 
the midas hot link mechanism).

If you are not sure how to use db_watch(), look inside midas/progs/odbedit.cxx search for 
db_watch() and search for the db_watch() callback function.

K.O.

The documentation for the sequencer loop says:

<quote>
LOOP [name ,] n ... ENDLOOP	To execute a loop n times. For infinite loops, "infinite" 
can be specified as n. Optionally, the loop variable running from 0...(n-1) can be accessed 
inside the loop via $name.
</quote>

In fact the loop variable runs from 1...n, as can be seen by running this exciting 
sequencer code:

1 COMMENT "Figuring out MSL"
2 
3 LOOP n,4
4   MESSAGE $n,1
5 ENDLOOP

> The documentation for the sequencer loop says:
> 
> <quote>
> LOOP [name ,] n ... ENDLOOP	To execute a loop n times. For infinite loops, "infinite" 
> can be specified as n. Optionally, the loop variable running from 0...(n-1) can be accessed 
> inside the loop via $name.
> </quote>
> 
> In fact the loop variable runs from 1...n, as can be seen by running this exciting 
> sequencer code:
> 
> 1 COMMENT "Figuring out MSL"
> 2 
> 3 LOOP n,4
> 4   MESSAGE $n,1
> 5 ENDLOOP

Indeed you're right. The loop variable runs from 1...n. I fixed that in the documentation.

Stefan