/Experiment ODB tree
Creating the /Experiment tree
The /Experiment ODB tree is created automatically when the ODB is first created.
Purpose
The /Experiment ODB tree contains information relevent to the experiment. Other optional keys are added by mhttpd or by the user to customize their experiment.
Examples
When initially created, the /Experiment tree contains the following keys:
[local:midas:S]/>ls -lrt /experiment
Key name Type #Val Size Last Opn Mode Value
---------------------------------------------------------------------------
Experiment DIR
Name STRING 1 32 14s 0 RWD midas
Buffer sizes DIR
SYSMSG DWORD 1 4 11h 0 RWD 100000
The following example shows the /Experiment tree for the DEAP experiment :
[local:deap:R]/>ls -lrt /experiment
Key name Type #Val Size Last Opn Mode Value
---------------------------------------------------------------------------
Experiment DIR
Name STRING 1 32 7s 0 RWD deap
Buffer sizes DIR
SYSMSG DWORD 1 4 23h 0 RWD 100000
SYSTEM DWORD 1 4 23h 0 RWD 640000000
BUF0 DWORD 1 4 23h 0 RWD 80000000
BUF1 DWORD 1 4 23h 0 RWD 80000000
....... other user-defined buffers not shown
MAX_EVENT_SIZE DWORD 1 4 23h 0 RWD 4194304
Menu Buttons STRING 1 256 5h 0 RWD Status, ODB, Messages, Elog, Alarms, Programs, History, MSCB, Sequencer, Config, Help
Transition debug flag INT 1 4 23h 0 RWD 0
Transition connect timeout INT 1 4 23h 0 RWD 10000
Transition timeout INT 1 4 23h 0 RWD 120000
edit on start DIR
Pedestals run BOOL 1 4 2h 0 RWD n
Write Data -> /Logger/Write data
BOOL 1 4 2h 0 RWD n
Comment -> /Experiment/Run Parameters/Comment
STRING 1 80 2h 0 RWD Sequenced Tests
Run Parameters DIR
Comment STRING 1 80 2h 0 RWD Sequenced Tests
Run Description STRING 1 256 7h 0 RWD Sequenced Tests
Prevent start on alarms BOOL 1 4 22h 0 RWD n
Prevent start on required prBOOL 1 4 22h 0 RWD n
Status items DIR
Experiment Name -> /Experiment/Name
STRING 1 32 7s 0 RWD deap
Start-Stop Buttons BOOL 1 4 5h 0 RWD y
Pause-Resume Buttons BOOL 1 4 5h 0 RWD n
Keys in /Experiment tree
The keys in the ODB /Experiment tree are described in the following sections.
/Experiment/Name
- Type: STRING
- Default:
Contains the name of the experiment. Filled automatically when the ODB is created with
/Experiment/Buffer Sizes subtree
Contains the sizes of the Midas Buffers for the experiment. Created with default values. The sizes can be changed to optimize the memory usage. See Event Buffer Size(s) for details. Other user-defined
buffers may be present (e.g. for event filtering).
/Experiment/Buffer Sizes/SYSMSG
- Type: DWORD
- Default: 100000 Bytes
Contains the size of SYSMSG buffer. This buffer is used for MIDAS messages.
/Experiment/Buffer Sizes/SYSTEM
- Type: DWORD
- Default: 8MBytes
Contains the size of SYSTEM buffer. See Event Buffer for details.
/Experiment/Menu Buttons
- Type: STRING
- Default: "Start, Pause, ODB, Messages, ELog, Alarms, Programs, History, Sequencer, Config, Help"
This key is added automatically by mhttpd to allow the Menu buttons that appear on the mhttpd Main Status Page to be customized by removing unnecessary buttons or by changing their order. If MSCB support is built into MIDAS, the MSCB Menu button will also be shown.
/Experiment/Edit on Start subtree
This optional subdirectory contains user-defined parameters which will be displayed for editing at the beginning of each run. See Defining Edit-on-start Parameters for details.