Hello Pierre-Andre,

thank you for your help with the interrupt handling. To close this case I'll
attach my interrupt
handling code for the SIS 3100 to this post as a reference. Maybe someone wants
to do something
similar in the future. 

I've decide to go for a C++ frontend therefore it is a class that handles
everything. The user only
has to provide a function pointer to the constructor that handles the interrupt
bitmask. The
interrupt handling is done with a timedwait within a separate thread. 

Cheers,
Clemens

> Hello Clemens,
> 
> The hardware readout is triggered by the interrupt within this thread. The
main thread poll on  
> the data availability (from the rb) to filter/compose the frontend event.
> In a similar multi-threaded implementation presently used in a dark matter
experiment we start 
> as many thread as necessary to constantly poll on the hardware for "data
fragment" collection.
> The event composition is done in the main thread through polling on the RBs.
> 
> Depending on the trigger rate and readout time, we can afford to analyze the
data fragment at 
> the thread level and add computed/summary information to the ring buffer on a
event-by-event 
> basis. This facilitate the overall event filtering happening later on in our
event builder. 
> 
> "polling the trigger signal?", I don't understand. You can poll on the trigger
condition but 
> then you don't need interrupt.
> 
> The original Midas interrupt implementation was to let the interrupt function
set a acknowledge 
> flag which is picked up by the standard midas polling function (user code) for
triggering the 
> readout. This method ensure a minimal time spent in the IRQ and works fine for
a single thread.
> 
> In regards of the CAEN V1742, we do have a VME driver for it, but it hasn't
been added to the 
> Midas yet (quite recent), but please don't hesitate to send us a copy.
> 
> Cheers, PAA
> 

Hello all,

As an addition to the driver functions I uploaded in this thread I would also have a
C++ class that handles everything for the V1742 modules and can be directly used
integrated into a C++ frontend. 

I would like to ask if you have policy for user supplied code like this? It's not a low
level driver but a frontend module that reads and controls the module, creates odb
hotlinks and handles the bank creating and storing of the data.

Best regards,
Clemens

EDIT: the question is, do you like to have  codes like this collected somewhere for
example this forum or would you prefer if I would post a link to some online repository =

Hello,

I'm currently trying to create a midas bank for basic temperature reading from the Arduino Yun, but when creating a bank the frontend crashed with a segfault, my
code currently looks like this:

INT read_event(char *pevent, INT off)
{
  WORD *data;
  //printf("before init\n");
  bk_init(pevent);
  //printf("after init\n");
  bk_create(pevent, "TEM0", TID_WORD, data); // <= we are dieing at this line
  //printf("after create\n");

  bk_close(pevent, data);

  return bk_size(pevent);
}

Does anyone have an Idea how to tackle this problem down? running a debugger is a little bit tricky on a this processor..

Thanks!

> Hello,
> 
> I'm currently trying to create a midas bank for basic temperature reading from the Arduino Yun, but when creating a bank the frontend crashed with a segfault, my
> code currently looks like this:
> 
> INT read_event(char *pevent, INT off)
> {
>   WORD *data;
>   //printf("before init\n");
>   bk_init(pevent);
>   //printf("after init\n");
>   bk_create(pevent, "TEM0", TID_WORD, data); // <= we are dieing at this line
>   //printf("after create\n");
> 
>   bk_close(pevent, data);
> 
>   return bk_size(pevent);
> }
> 
> Does anyone have an Idea how to tackle this problem down? running a debugger is a little bit tricky on a this processor..
> 
> Thanks!

Two bugs:

bk_create(pevent, "TEMO0", TID_WORD, &data);

note the "&" in front of data. Then you have to increment the pointer for each byte you add to the bank:

  *data = <temp>;
  data++;
  bk_close(pevent, data);

this way the bk_close() function know how much data you added to the bank.

Cheers,
Stefan

> INT read_event(char *pevent, INT off)
> {
>   WORD *data;
>   bk_create(pevent, "TEM0", TID_WORD, data); // <= we are dieing at this line
> }

The declaration of bk_create() in midas.h is wrong:

void EXPRT bk_create(void *pbh, const char *name, WORD type, void *pdata);
should be
void EXPRT bk_create(void *pbh, const char *name, WORD type, void **pdata);

Notice the extra "*" in "void**pdata" to indicate that it takes a pointer to the pointer to the data.

With the correct definition, you should get a compile error (type mismatch).

With the wrong current definition, you should have gotten a warning about "use of uninitialized variable 'data'", but some compilers with some settings do not generate this warning.

As it is, without looking at an example (highly recommended) and reading documentation (do we even have a "frontend writing guide"?!?) you have
no way to tell if you should pass "data" or "&data" to bk_create().

Thank you for reporting this problem.

P.S. As for running on Arduino, for slow controls type application, any CPU and network speed should be okey,
but memory use is always a concern, so please speak up if you run into problems. We routinely run MIDAS frontends
on linux machines with 512M and 128M RAM (1GHz CPU, 100 and 1000 M/s ethernet).

K.O.

> With the correct definition, you should get a compile error (type mismatch).
> 
> With the wrong current definition, you should have gotten a warning about "use of uninitialized variable 'data'", but some compilers with some settings do not generate this warning.

I redefined the definition of the bk_create function to contain a void **pdate pointer, but that did not really help. Now I get a compiler error:

"Incompatible pointer type passing 'DWORD **' to parameter of type 'void **', so I need an explicit cast each time

bk_create(... (void **)&pdata);

But I think this is better than what we had before so I leave it. Please note that all front-ends using bk_create need to be modified accordingly to suppress this warning.

/Stefan

Hi all,
  I've started receiving the following error that I can't track down.  Does
anyone have a suggestion for where to start looking for the cause of this?

[Analyzer,ERROR] [odb.c:9460:db_open_record,ERROR] struct size mismatch for "/"
(expected size: 576, size in ODB: 0)

This error prevents me from running two runs in a row.  I have to close the DAQ
and restart to take multiple runs.  Also it prevents me from running the analyzer
in offline mode. 

I also noticed that several for the ODB directories no longer have the same html
format when viewed through the browser.  I've attached a screen print of the
"/Logger/Channels" page.

Thanks,
Robert

We have a MIDAS frontend that provides both the readout of raw events 
and the processing of raw events into several distinct derived datasets. 
For one type of derived dataset there is a derived event for 
each raw event. For other types of derived datasets there's a
derived event for every N raw events. We'd like to have the different 
derived event types sent to different buffers / shared memory segments 
and stored in different midas files.

I was thinking of defining a separate equipment for each type of 
derived data. Each equipment would have a different buffer name so
the data would go to different buffers and thereafter to different 
midas files. I was also thinking of defining each equipment as
a "polled event" but with a unique "source ID". I believe the user 
poll_event() function is passed the "source ID" of the equipment
type and therefore could return success/fail based on whether or
not the particular derived event with that source ID is available 
for readout. Each equipment for each derived dataset would have 
a unique readout routine to create and fill the midas databanks 
for that derived event type.

The above scheme is similar to the midas documentation example
of a frontend with a trigger equipment and a scaler equipment
However, the scaler / trigger example uses two different event
types - EQ_POLLED for trigger and EQ_PERIODIC for scaler. I'd like
to use several EQ_POLLED equipments that are distinguished by
their source ID's

Is this a sensible scheme for make different data streams of
different derived event types from a single frontend? Has anyone
tried something similar? 

Hi Tim,

Multiple Polling equipment are possible, but you may have to balance the polling 
time based on the expected trigger rate for each equipment due to the 
acquisition/processing time of each equipment.

But instead of using the event buffer destination for the dataset selection, you 
could use the trigger mask and the event ID modified at the user code level from 
a single equipment.

Using the macros such as TRIGGER_MASK(pevent), EVENT_ID(pevent) you can modify 
on the fly their assignment. All go through the SYSTEM buffer as usual.

You use the data logger capability of multiple channels to steer the data in 
different files. 
Each logger channel requires a definition of the type of event that you want to 
record. EventID, TriggerMask can in this case be used to select a particular 
type of event.
I used this option and if I recall correctly, the trigger mask is the one you 
want to base your selection upon. This gives you up to 16 channels (bitwise). 
the eventID should remain -1, but it is a valid information from the FEs.

Cheers, PAA


> 
> 
> We have a MIDAS frontend that provides both the readout of raw events 
> and the processing of raw events into several distinct derived datasets. 
> For one type of derived dataset there is a derived event for 
> each raw event. For other types of derived datasets there's a
> derived event for every N raw events. We'd like to have the different 
> derived event types sent to different buffers / shared memory segments 
> and stored in different midas files.
> 
> I was thinking of defining a separate equipment for each type of 
> derived data. Each equipment would have a different buffer name so
> the data would go to different buffers and thereafter to different 
> midas files. I was also thinking of defining each equipment as
> a "polled event" but with a unique "source ID". I believe the user 
> poll_event() function is passed the "source ID" of the equipment
> type and therefore could return success/fail based on whether or
> not the particular derived event with that source ID is available 
> for readout. Each equipment for each derived dataset would have 
> a unique readout routine to create and fill the midas databanks 
> for that derived event type.
> 
> The above scheme is similar to the midas documentation example
> of a frontend with a trigger equipment and a scaler equipment
> However, the scaler / trigger example uses two different event
> types - EQ_POLLED for trigger and EQ_PERIODIC for scaler. I'd like
> to use several EQ_POLLED equipments that are distinguished by
> their source ID's
> 
> Is this a sensible scheme for make different data streams of
> different derived event types from a single frontend? Has anyone
> tried something similar? 

Hello,

I'm wondering if it would be possible to add the ability to lock ODB variables as 
a sequencer command.

The "Lock when running" directory in the ODB /Experiment tree seems to apply only 
during a run - I'd like a way to lock a variable outside a run.

Is this possible within the sequencer?  Or have I overlooked existing 
functionality?

Thanks!

Amy

I am trying to start a program (fronend) from a custom page. What is the best
way to do that? Would ODBRpc() do this? if so can anyone give me an example of
how to do this. Thanks.

> I am trying to start a program (fronend) from a custom page. What is the best
> way to do that? Would ODBRpc() do this? if so can anyone give me an example of
> how to do this. Thanks.

You have a look at the documentation:

http://ladd00.triumf.ca/~daqweb/doc/midas-old/html/RC_mhttpd_defining_script_buttons.html

Cheers,
Stefan

> > I am trying to start a program (fronend) from a custom page. What is the best
> > way to do that? Would ODBRpc() do this? if so can anyone give me an example of
> > how to do this. Thanks.
> 
> You have a look at the documentation:
> 
> http://ladd00.triumf.ca/~daqweb/doc/midas-old/html/RC_mhttpd_defining_script_buttons.html
> 
> Cheers,
> Stefan

Hi Stefan, thanks for the quick reply. I guess my question was not clear enough.

My aim is to create a button which mimics the "Start/Stop" button functionality in the
"Programs" page where we start all the front-ends for the various equipment. The idea is that
the user will use a simple interface in a custom page (not the status page) which sets up the
equipment needed for a specific type of measurement.

thanks
Zaher

> Hi Stefan, thanks for the quick reply. I guess my question was not clear enough.
> 
> My aim is to create a button which mimics the "Start/Stop" button functionality in the
> "Programs" page where we start all the front-ends for the various equipment. The idea is that
> the user will use a simple interface in a custom page (not the status page) which sets up the
> equipment needed for a specific type of measurement.

All functions in midas are controlled through special URLs. So the URL

http://<host:port>/?cmd=Start&value=10

will start run #10. Similarly with ?cmd=Stop. Now all you need is to set up a custom button, and use the 
OnClick="" JavaScript method to fire off an Ajax request with the above URL. 

To send an Ajax request, you can use the function XMLHttpRequestGeneric which ships as part of midas in the 
mhttpd.js file. Then the code would be

<input type="button" onclick="start()">

and in your JavaScript code:

...
function start()
{
   var request = XMLHttpRequestGeneric();

   url = '?cmd=Start&value=10';
   request.open('GET', url, false);
   request.send(null);
}
...


Cheers,
Stefan

Thank you very much, this is exactly what I need and it works.

Zaher

> All functions in midas are controlled through special URLs. So the URL
> 
> http://<host:port>/?cmd=Start&value=10
> 
> will start run #10. Similarly with ?cmd=Stop. Now all you need is to set up a custom button, and use the 
> OnClick="" JavaScript method to fire off an Ajax request with the above URL. 
> 
> To send an Ajax request, you can use the function XMLHttpRequestGeneric which ships as part of midas in the 
> mhttpd.js file. Then the code would be
> 
> <input type="button" onclick="start()">
> 
> and in your JavaScript code:
> 
> ...
> function start()
> {
>    var request = XMLHttpRequestGeneric();
> 
>    url = '?cmd=Start&value=10';
>    request.open('GET', url, false);
>    request.send(null);
> }
> ...
> 
> 
> Cheers,
> Stefan

For our MIDAS installation at Fermilab, it is necessary that we be able to write to a PosgresQL 
database (MySQL is not supported here). This will be required of both mlogger and mscb. 

Has anyone done this before? And do you know of a relatively simple way of implementing it, or do 
we need to replicate the mysql functions that are already in the mlogger/mscb code to add functions 
that perform the equivalent Posgres commands?

Thanks!
Wes

> For our MIDAS installation at Fermilab, it is necessary that we be able to write to a PosgresQL 
> database (MySQL is not supported here). This will be required of both mlogger and mscb. 
> 
> Has anyone done this before? And do you know of a relatively simple way of implementing it, or do 
> we need to replicate the mysql functions that are already in the mlogger/mscb code to add functions 
> that perform the equivalent Posgres commands?
> 
> Thanks!
> Wes

Hi Wes

I did this a few years ago, and replicated the mysql functions within mlogger. 

Lee

Dear Midas users, 

As part of our commitment to  Midas improvements, this year Dr. Stefan Ritt is coming to Vancouver 
BC, CANADA for his biennial visit from the end of June to mid-July 2015.

A Data acquisition system now a days is expected to do more than just collect data, it has become an 
integrated process with various types of data source for monitoring, control, storage and analysis, 
as well as data visualization using modern techniques.
MIDAS stands for "Maximum Integration Data Acquisition System". It is interesting to think that this 
name was given 20 years ago when none of the interconnectability was available at today's level. 

So in order to keep MIDAS current with new technology and provide a better DAQ tool, we plan to 
discuss topics that would address integration in a larger format, the goal being to provide to the 
users a more robust and "simple" way of doing their work. We will also be working on improvements 
and the addition of new features.

Towards the end of Stefan's visit, we will have a "Midas seminar" with a few presentations related 
to specific experiments managed by Triumf. Each talk will bring a different aspect of the DAQ that 
Midas had to deal with. This will potentially be a good starting point for further discussions.

We will broadcast this seminar. Webcast information will be provided in a later message, preliminary 
date: 13 or 14 July. I would encourage you to participate in this event, if not in person, at least 
virtually. It is a good time for you to send to Stefan (midas@psi.ch) or myself (midas@triumf.ca), 
questions, requests, wishes, issues that you experience, general comment that has been on the back 
of your mind but you didn't manage to submit to us. This would help us to better understand how 
Midas is used, where it is used, and what can be addressed to better serve your needs as a user. 

Let us know how Midas is helping you, we would really appreciate it. Let us also know if you are 
thinking of attending this virtual seminar. 

If you happen to be in the Vancouver vicinity around the end of June, you are most welcome to join 
us at Triumf. The Midas team will take the time to chat about Data Acquisition and perhaps the 
benefit of our west coast weather!

Best Regards, Pierre-André Amaudruz