The current implementation of ODB links has the problem that once a link is
created, it cannot be changed any more through odbedit. This is because each
"set" command works on the destination of the link instead of the link. The same
happens when one loads a *.odb file. To overcome this problem, two new functions
db_set_link_data() and db_set_link_data_index() have been implemented. They
resemble their counterparts db_set_data() and db_set_data_index(), but they can
be used to directly modify a link instead of the link target. I use these
functions now in odbedit and db_paste() so that the above described problems are
fixed now. I do not expect any side effect of this, but if people experience
problems with db_paste(), please let me know.

I implemented improved alarm conditions in the alarm system. Now one can write
conditions like

  /Equipment/HV/Variables/Input[*] < 100

or 

  /Equipment/HV/Variables/Input[2-3] < 100

to check all values from an array or a certain range. If one array element
fulfills the alarm condition, the alarm is trigger. In addition, bit-wise alarm
conditions are possible

  /Equipment/Environment/Variables/Input[0] & 8

is triggered if bit #2 is set in Input[0].

The changes are committed to SVN revision 4242.

Dear All,

I have a problem when testing the V792N 16 CH QDC with the V1718 VME-USB 
Bridge on Scientific Linux 5.1 i386 (kernel 2.6.18-53.1.21.e15).

The problem is that the V792N does not response normally after a few minutes 
of continuous polling and readout of data. It seems like the V792N is hanged 
and a hardware reset of the VME system is required to bring it working again. 
If I do not poll for DREADY first and directly read the Output Buffer 
continuously, the system can work properly.

I have worked on this problem many days but I cannot find any clues to solve 
it. I have tried to use the CAENVMEDemo program (with some modifications) to 
do the same thing (polling and readout) and it works fine. CAEN technical 
support also doesn't know why the VME system is hanged. I think it might be a 
problem of MIDAS itself. I have tried with MIDAS revision 4132 and the trunk 
version, but the problem is still there. Is there any parameter in MIDAS 
(buffer size etc?) which may cause this problem? I have attached my frontend 
code and drivers for your reference.

Thank you for your kind attention.

Best Regards,
Jimmy

Some improvement of custom pages have been implemented. The idea behind is that
a custom page would contain a large background image containing indicators but
also controls. While indicators (values, bars) are already available, the field
of controls have been improved.

Edit boxes floating on top of a graphic
---------------------------------------

The first option has been there from the beginning, but was never documented. It
makes it possible to put an edit box right on top of a graphic by means of a CSS
style tag. The custom page code could look like this:

<div style="position:absolute; top:100px; left:50px;">
<odb src="/Runinfo/run number" edit=1>
</div>
<img src="cusgom.gif">

The "div" tag surrounding the "odb" tag places this directly on top of the
"custom.gif" image, where it can be clicked to be edited.

Password protection of an edit box
----------------------------------

Being able to control an experiment through a web interface of course rises the
question about safety. This is not so much about external access (for which we
have other protection schemes like host lists etc.) but it's about accidental
access by the normal shift crew. If a single click on a web page opens a
critical valve, this might be a problem. In order to restrict access to some
"experts", an additional password can be chosen for all or some controls on a
custom page. This is done by a new option in the "odb" tag and by adding a small
JavaScript function into the custom page:

<script type="text/javascript">
<!--
function promptpwd(path)
{
    pwd = prompt('Please enter password', '');
    document.cookie = "cpwd=" + pwd;
    location.href = path;
}
//-->
</script>

...

<odb src="/..." edit=1 pwd="CustomPwd">

...

If the "pwd" option is present in the "odb" tag, mhttpd establishes a call to
the promptpwd() function if one click on the value. The password is then asked
from the user and submitted as a cookie. mhttpd then check this password against
the ODB entry

/Custom/Pwd/CustomPwd

and shows an error if they don't match. By using an explicit name ("CustomPwd"
in the above example) one can use a single password for all controls on a page,
or one could use several passwords on the same page. Like a shift crew password
for the less severe controls (/Custom/Pwd/ShiftPwd), and an "expert" password
(/Custom/Pwd/ExpertPwd) for the critical things. This password is of course not
secure in the sense that it's placed in plain text into the ODB, it's more to
prevent accidental modifications of things.

Area map to toggle values
-------------------------

Sometimes it's desirable to toggle a value, like the state of a valve. This can
be done now with a new function like this:

<map name="Custom1">
<area shape="rect" coords="40,200,100,300" alt="Main Valve"
  href="Custom1?cmd=Toggle&odb=/Equipment/Environment/Variables/Output[2]">
</map>
<img src="cusgom.gif" usemap="#Custom1">

This defines a clickable map on top of the custom image. The area(s) should
match with some areas on the image like the box of a valve. By clicking on it,
the supplied path to the ODB is used (in this case
"/Equpiment/Environment/Variables[2]") and it's value is toggled (set to 0 if it
is 1, set to 0 if it is 1). If the valve value is then used in the image via a
"fill" statement to change the color of the valve, it can turn green or red
depending on it's state.

Are map with password check
---------------------------

The above area map can be combined with the password check. To do so, one needs:

<area shape="rect" coords="40,200,100,300" alt="Main Valve"
  href="#"
onClick="promptpwd('Custom1?cmd=toggle&pnam=CustomPwd?odb=/Equipment/Environment/Variables/Output[2]')">

in combination with the JavaScript from above.


An example of the are map technology is shown in the attachment. This page from the MEG experiment at PSI
shows a complex gas system. The valves are represented as green circles. If they are clicked, they close
and become red (after the user successfully supplied the correct password).

> > The current versions of mlogger SVN 4215 is flooding our message system with
> > stuff like
> > 
> > > Tue Jun 10 16:42:01 2008 [Logger,INFO] Configured history with 22 events
> > > Tue Jun 10 16:42:14 2008 [Logger,INFO] Configured history with 22 events
> > > Tue Jun 10 16:42:26 2008 [Logger,INFO] Configured history with 22 events
> 
> Problem confirmed on the M11 DAQ system at TRIUMF. We definitely do nothing funny
> there, so what is going on? Will investigate.

The only place I see where this could happen is in mlogger.c, lines 3064ff:

   /* check if event size has changed */
   db_get_record_size(hDB, hKey, 0, &size);
   if (size != hist_log[i].buffer_size) {
      close_history();
      open_history();
      return;
   }

The record size corresponds to /Equipment/<name>/Variables. If this array changes in
size, it will trigger the re-definition of the history. So please have a look there
and check why the record size changes.

> The current versions of mlogger SVN 4215 is flooding our message system with
> stuff like
> 
> > Tue Jun 10 16:42:01 2008 [Logger,INFO] Configured history with 22 events
> > Tue Jun 10 16:42:14 2008 [Logger,INFO] Configured history with 22 events
> > Tue Jun 10 16:42:26 2008 [Logger,INFO] Configured history with 22 events

Problem confirmed on the M11 DAQ system at TRIUMF. We definitely do nothing funny
there, so what is going on? Will investigate.

K.O.

Since the very beginning midas had the problem that the last event of a run was
sometimes missing in the data. While for most experiments this is not an issue,
it starts to hurt on experiments using event building (front-end 1 and front-end
2 in the example below). A missing event can screw up the event builder on the
next begin of run, where the "missing event" would show up as the first event of
the new run, triggering an event mismatch error in the event builder.

After some analysis, we identified the problem as follows. Assume FE1 controls
the trigger, while FE2 generates the second event fragment.

1) Stop is requested to FE1
2) tr_stop gets called on FE1
3) tr_stop calls end_of_run() use code
4) end_of_run() disables the trigger
5) FE1 finishes stop transition
6) Stop is requested to FE2
7) FE2 finishes stop transition

What can now happen is the following: An additional event occurs between 2) and
4). This event triggers ADCs and TDCs, and is then stored in the front-end
hardware. FE2 sees this event, since it has not yet done the stop transition,
and reads it out. FE1 is however already in the end_of_run() routine, and simply
disables the trigger, without reading this last event, and thus causing the
event mismatch at the beginning of the next run.

To fix the problem, the framework in mfe.c was changed:

1) Stop is requested to FE1
2) tr_stop gets called on FE1
3) tr_stop calls end_of_run() use code
4) end_of_run() disables the trigger
4b) tr_stop calls check_polled_events()
5) FE1 finishes stop transition
6) Stop is requested to FE2
7) FE2 finishes stop transition

The new routine check_polled_events checks if there is any more event in the
hardware by calling the user polling routine. If there is one more event, calls
the user readout routine and sends it to the back-end before concluding the run
transition. 

This modification solved our problem at the MEG experiment at PSI, but it might
be good that all experiments using event building update midas to revision 4225.

I do not expect any bad side effect, but one never knows. So if there are new
problems caused by this modification, please report.

- Stefan

> The current versions of mlogger SVN 4215 is flooding our message system with
> stuff like
> 
> > Tue Jun 10 16:42:01 2008 [Logger,INFO] Configured history with 22 events
> > Tue Jun 10 16:42:14 2008 [Logger,INFO] Configured history with 22 events
> > Tue Jun 10 16:42:26 2008 [Logger,INFO] Configured history with 22 events
> 
> This is fatal to us and blowing up the midas.log like hell. I would prefer if
> one could flag these kind of messages (ODB /Logger/..), i.e. enable and disable
> it. At the moment I have to comment it out in the source code since we cannot
> work with it.

I just sent the attached message to Stefan - please read it.

Before we take any action, we need to understand why history is being
reconfigured every 10 seconds (according to your logfile snippet).

Are you starting a new run every 10 seconds?

If that is what you do and that is your intent, I guess it is atypical usage of
MIDAS and the message from the mlogger is offensive and should be removed/disabled.

If something else is going on, we need to understand it before we sweep trouble
under the carpet by disabling this message.

K.O.

Stefan - there is more bad news - the message is produced when the history
is being reconfigured. This only is supposed to happen when the mlogger
starts or at the begin of run.

So these messages are just a tip of an iceberg of some other trouble.

The logic of when history is reconfigured I did not change. So likely
the trouble existed before, but you did not know about it.

We can kill the message, but why is the history being reconfigured
at a rate that "floods the log file"? That cannot possibly be good.

K.O.

The current versions of mlogger SVN 4215 is flooding our message system with
stuff like

> Tue Jun 10 16:42:01 2008 [Logger,INFO] Configured history with 22 events
> Tue Jun 10 16:42:14 2008 [Logger,INFO] Configured history with 22 events
> Tue Jun 10 16:42:26 2008 [Logger,INFO] Configured history with 22 events

This is fatal to us and blowing up the midas.log like hell. I would prefer if
one could flag these kind of messages (ODB /Logger/..), i.e. enable and disable
it. At the moment I have to comment it out in the source code since we cannot
work with it.

Cheers,
  Andreas 

Hi All,

I am testing the libraries provided by CAEN with the sample softwares in the 
bundle CD. The Windows sample program works fine, but I cannot get started with 
the Linux sample program. When I run CAENVMEDemo in Scientific Linux 5.1, it 
gives me a message "Error opening the device". I have followed the instructions 
in CAENVMElibReadme.txt: 
- compile and load the device driver v1718.ko
- install the library libCAENVME.so

Does anyone have any experience of using V1718 in Scientific Linux? Thanks.

Regards,
Jimmy


> Hi All,
> 
> Is there any example code for using MIDAS with the CAEN VME-USB Bridge V1718? 
> Thanks.
> 
> Regards,
> Jimmy

Hi All,

Is there any example code for using MIDAS with the CAEN VME-USB Bridge V1718? 
Thanks.

Regards,
Jimmy

> > Here is the list of known problems I am aware of and of fixes not yet committed to midas svn:
> > 1) added variable /equiment/foo/common/PerVariableHistory
> 
> corrected in svn revision 4203, read
> http://savannah.psi.ch/viewcvs/trunk/src/mlogger.c?root=midas&rev=4203&sortby=rev&view=log

Was still broken - all should work in revision 4207.

> > 2) writing compressed midas files (foo.mid.gz) crashes the mlogger when file
> > size reaches 2 GBytes. This problem could be new in SL5.1.

It turns out that on SL5 and SL5.1 (and others?) the 32-bit version of ZLIB opens the
compressed output file without the O_LARGEFILE flag, this limits the file size to 2 GB.

Fixed by opening the file ourselves, then attach compression stream using gzdopen().

Revision 4207. (Not tested on Windows - may be broken!)

> > 5) mhttpd history "export" button needs to be fixed (by request from ALPHA). At
> > present it either does not return all exiting data or crashes mhttpd. (no fix)
> 
> (no change)
> 
> > 6) mhttpd ODB editor in "set value" page, the "cancel" button is broken (needs
> > to be corrected for "relative URL").
> 
> Apply this patch to src/mhttpd.c
> 
> @@ -11156,10 +11190,7 @@
>           sprintf(str, "SC/%s/%s", eq_name, group);
>           redirect(str);
>        } else {
> -         strlcpy(str, path, sizeof(str));
> -         if (strrchr(str, '/'))
> -            strlcpy(str, strrchr(str, '/')+1, sizeof(str));
> -         redirect(str);
> +         redirect("./");
>        }
> 
> > 7) mhttpd needs AJAX-style methods for reading and writing ODB. (no fix)
> 
> (no change)
> 
> K.O.

> Here is the list of known problems I am aware of and of fixes not yet committed
> to midas svn:
> 
> 1) added variable /equiment/foo/common/PerVariableHistory

corrected in svn revision 4203, read
http://savannah.psi.ch/viewcvs/trunk/src/mlogger.c?root=midas&rev=4203&sortby=rev&view=log

> 2) writing compressed midas files (foo.mid.gz) crashes the mlogger when file
> size reaches 2 GBytes. This problem could be new in SL5.1.

(no change)

> 3) when a midas client becomes unresponsive, runs cannot be stopped using the
> "stop" button in mhttpd. This is because cm_transition() loops over all attached
> clients, but never removes clients that are known to be dead. Proposed fix is to
> call cm_check_client() for each client before calling their rpc transition handler.

Fixed in SVN revision 4198, read
http://savannah.psi.ch/viewcvs/trunk/src/midas.c?root=midas&rev=4201&sortby=rev&view=log

> 4) the discussed before fix for reading broken history files (skip bad data).

Fixed in SVN revision 4202, read https://ladd00.triumf.ca/elog/Midas/482

> 5) mhttpd history "export" button needs to be fixed (by request from ALPHA). At
> present it either does not return all exiting data or crashes mhttpd. (no fix)

(no change)

> 6) mhttpd ODB editor in "set value" page, the "cancel" button is broken (needs
> to be corrected for "relative URL").

Apply this patch to src/mhttpd.c

@@ -11156,10 +11190,7 @@
          sprintf(str, "SC/%s/%s", eq_name, group);
          redirect(str);
       } else {
-         strlcpy(str, path, sizeof(str));
-         if (strrchr(str, '/'))
-            strlcpy(str, strrchr(str, '/')+1, sizeof(str));
-         redirect(str);
+         redirect("./");
       }

> 7) mhttpd needs AJAX-style methods for reading and writing ODB. (no fix)

(no change)

K.O.

> > But to make things more interesting we had another history outage this week...
> > Anyhow, I now have a patch to allow hs_read() to "skip the bad spots" in history files.
> 
> [Stefan suggested]
>
>   if ((irec.time - last_irec_time) > 3600*24)


Yes, your stronger check works quite nicely. The whole patch is now committed into SVN,
revision 4202.

This is how it all works:

0) teach hs_gen_index() to skip over bad data. This is important because hs_read() only
looks at data records listed in the index file: if bad data is omitted from the index,
hs_read() will never see it and we do not need to worry about it in hs_read().
0a) because hs_gen_index() does not check validity of time stamps, we still need to check
them in hs_read().
1) in hs_read(), if we detect bad data (invalid headers, bad time stamps, etc), we
regenerate the index files - this removes a while class of bad data. We also look at time
stamps carefully and ignore records where time goes backwards (usually bad data) and ignore
records with time in the future beyound the end of the current history file (each history
file only contains 24*60*60 seconds = 1 day's worth of data).

While certainly not bullet-proof, these changes should make it easier to deal with
corruption of history files.

K.O.

Here is the list of known problems I am aware of and of fixes not yet committed
to midas svn:

1) added variable /equiment/foo/common/PerVariableHistory breaks stuff (mostly
mhttpd). It is not clear how this problem escaped my pre-commit checks. This
per-equipment variable enables the per-variable history for the given equipment.
Local consensus is that this variable should not be in "common" and should not
be in "settings". Probably in "/history"? Or have only one variable to enable
this for all equipments at once (like we do in ALPHA).

2) writing compressed midas files (foo.mid.gz) crashes the mlogger when file
size reaches 2 GBytes. This problem could be new in SL5.1.

3) when a midas client becomes unresponsive, runs cannot be stopped using the
"stop" button in mhttpd. This is because cm_transition() loops over all attached
clients, but never removes clients that are known to be dead. Proposed fix is to
call cm_check_client() for each client before calling their rpc transition handler.

4) the discussed before fix for reading broken history files (skip bad data).

5) mhttpd history "export" button needs to be fixed (by request from ALPHA). At
present it either does not return all exiting data or crashes mhttpd. (no fix)

6) mhttpd ODB editor in "set value" page, the "cancel" button is broken (needs
to be corrected for "relative URL"). (no fix)

7) mhttpd needs AJAX-style methods for reading and writing ODB. (no fix)

K.O.

Here is the list of known problems I am aware of and of fixes not yet committed
to midas svn:

FYI - in conjunction with replacement of ladd00.triumf.ca, this MIDAS ELOG has been updated to the latest 
version 2.7.3-2058. Please report any problems or anomalies. K.O.

> > I am now ready to commit changes to midas.h and odb.c that add the const attributes to ODB 
> > access functions db_xxx(), i.e.
> > INT db_rename_key(HNDLE hDB, HNDLE hKey, char *name)
> > becomes
> > INT db_rename_key(HNDLE hDB, HNDLE hKey, const char *name)
>
> I fully approve your idea.

Committed revision 4172.

K.O.

> Now that we use more and more C++, lack of "const" attribute on most midas functions is causing some 
> problems. I am now ready to commit changes to midas.h and odb.c that add the const attributes to ODB 
> access functions db_xxx(), i.e.
> INT db_rename_key(HNDLE hDB, HNDLE hKey, char *name)
> becomes
> INT db_rename_key(HNDLE hDB, HNDLE hKey, const char *name)
> 
> If we proceed with this conversion, and it does not cause major havoc, I can continue and "const"ify the 
> rest of midas.h. I note that the mxml functions appear to already have the correct "const" declarations.
> 
> P.S. Adding the "const" attribute caught a few places where we were modifying a "char*" string passed by 
> the caller. This is undesirable if we are passed a string literal, i.e. db_rename_key(...,"foo"), and it is a 
> complete disaster in conjunction with C++ strings, i.e. db_rename_key(...,foo.c_str())

I fully approve your idea. You are absolutely right that it also will help to prevent errors such as modifying
fixed strings. I was just too lazy to do that, because it requires some additional code like:

func(const char *p)
{
char str[256];

  strlcpy(str, p, sizeof(str));
  strlcat(str, ...)
} 

So if you do it, it's great!

Now that we use more and more C++, lack of "const" attribute on most midas functions is causing some 
problems. I am now ready to commit changes to midas.h and odb.c that add the const attributes to ODB 
access functions db_xxx(), i.e.
INT db_rename_key(HNDLE hDB, HNDLE hKey, char *name)
becomes
INT db_rename_key(HNDLE hDB, HNDLE hKey, const char *name)

If we proceed with this conversion, and it does not cause major havoc, I can continue and "const"ify the 
rest of midas.h. I note that the mxml functions appear to already have the correct "const" declarations.

P.S. Adding the "const" attribute caught a few places where we were modifying a "char*" string passed by 
the caller. This is undesirable if we are passed a string literal, i.e. db_rename_key(...,"foo"), and it is a 
complete disaster in conjunction with C++ strings, i.e. db_rename_key(...,foo.c_str())

K.O.