Notes for using the Neutron Wall subsystem
When
you start a MIDAS session from the euroball ID you must run the
experiment ancillary. As the
session starts look in the Session Log window for the message You are
now working with the experiment ancillary. If you see anything else (such
as You are now working with the
experiment EUROBALL) then
Go to the Euroball Experiment
Control window
Click on More Actions at
the bottom
Select Show Main Menu
from the list
Go to the Euroball main menu
window
Click on Access Control
Select Experiment Access
from the list
Go to the Accessing an
Experiment window
Click on the button Leave
Select ancillary from the
list
Click on the button Join
Now
look for the message You are now working with the experiment ancillary in
the Session Log window.
This
setting can be saved as the default value.
In
the window Euroball Experiment Control check that the checkbox labelled VME
Electronics is checked. This should be true if you are using the main
Euroball system control workstation (eb63).
If the box is not checked then click on it to enable.
This
will enable the actions associated with the Neutron Wall and other VME
electronics when you use the main GO and STOP buttons.
In order that the VME control
works correctly it is essential that the Euroball session uses the same
VME configuration that was used when the configuration was downloaded into the
VME server (see later). The
configuration loaded into the VME server is written to the file
/MIDAS/experiments/ancillary/[server_name]_current_configuration. For the
experiment ancillary the VME server for the ancillary electronics is vme.
Hence [server_name] is vme in this case.
The
VME Configuration and Control window can be opened by clicking on the Open
button for VME Electronics in the Euroball Experiment Control
window. When the software starts the configuration held in
/MIDAS/experiments/ancillary/vme_current_configuration is loaded automatically.
Only modules mentioned in the
configuration will be controlled by the experiment STOP and GO
button.
The VME control window is
started by clicking the Open button for VME Electronics in the Euroball
Experiment Control window. This window allows you to edit the VME
electronics configuration. It is
strongly advised that you do not change the VME hardware configuration (and in
particular any module generating VME data) unless you really know what you are
doing.
If
you do change the VME hardware configuration you will need to edit this
configuration window. You can save changes made or restore a previously
saved configuration by clicking on the
button Save/Restore Configuration.
To load a new VME configuration
(or restore an old one) into the VME server click on the button Load
Configuration into Register Server.
If you have changed the configuration of modules which generate VME data
then you will also need to recreate the Look Up Table (LUT) and VME Address
Table (VAT) files. You will be prompted to do this by the Load operation and
also by clicking on the button Generate LUT & VAT files.
The
Load Configuration function also performs the SETUP action on all
VME modules. This will include setting all thresholds and discriminators in ADC
modules to default values and setting the VME address information for all data
sources. There is a SETUP electronics button in the VME Configuration
& Control window which can be used at any time to perform the SETUP
action.
Note
– The SETUP action checks that all modules perform a certain VME cycle
correctly. If a module in your configuration is missing or not operating
correctly you will get a warning message. This is the only time that VME
modules are checked for correct operation.
The VME option in the pull down menu Parameter
Save/Restore in the Euroball Experiment Control window or the button
Save/Restore Setup in the VME Configuration & Control window
will start a window (Saving and
Restoring VME Module Setups) which enables all the adjustable parameters
for the VME modules in the configuration to be saved or enables a previously
saved set of parameters to be restored.
You
can start the control window for any VME module either from the VME menu
in the Main Menu or by double clicking on the module in the VME
configuration window.
The
button RESET electronics in the VME Configuration & Control
window will set all VME modules into a good state. It does not perform the
SETUP operation. Hence any custom setting of modules is preserved.
The GO button in the Euroball
Experiment Control (or the GO
Electronics button in the VME Configuration & Control window)
will set all VME electronics into the GO state.
The STOP button in the Euroball
Experiment Control (or the HALT
Electronics button in the VME Configuration & Control window)
will set all VME electronics into the STOPPED state.
Neutron Wall Interface
This is a VME module which you
will find in the Neutron Wall electronics VME crate. It provides the interface
between the VME adc readout system and the DT32 bus and also to the main
Trigger system. You can start the Neutron Wall Interface Setup window by
selecting Neutron Wall from the VME Module Setup menu in the Euroball
Main Menu. The setup parameters for the interface can be saved and restored
in the same manner as for all VME modules.
The LUT (Look Up Table) needed to convert the VME data addresses (module GEO address and adc subaddress) to the VXI data addresses (group and item) are loaded automatically by the software in the Neutron Wall VME processor. This uses the LUT file /MIDAS/experiments/ancillary/LUT.vme which is created by the button Generate LUT & VAT files in the VME Configuration & Control window.
Always
STOP data acquisition if at all possible.
If this system is restarted
for any reason then it is necessary to reload the VME configuration into the
processor. Go to the VME Configuration & Control window and click
the button Load Configuration into Register Server.
You
will be prompted to do this by the system restart procedure
Then go to the VME
Configuration & Control window and click on RESET electronics
and then use Save/Restore Setup to restore all adjustable parameters and
get all your VME hardware back into a good known state.
As long as the VME
Electronics checkbox in the Subsystems required list is selected in
the Euroball Experiment Control window then any action required on the
VME electronics at GO and STOP is performed automatically.