/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.
/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/MAX_EVENT_SIZE
- Type: DWORD
- Default: 4MBytes
The key specifies the maximum event size that can be acquired. The default value is half the size of the SYSTEM buffer. It can be increased if required (see Event Buffer).
/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. Without the "Pause" being present in the list of menu buttons, the run cannot be paused/resumed, but only started/stopped. This is required by some experiments.
If MSCB support is built into MIDAS, the MSCB Menu button will also be shown.
/Experiment/Transition debug flag
- Type: INT
- Default: 0
If flag is set to 1, messages reporting transition progress will be output.
/Experiment/Transition connect timeout
- Type: INT
- Default: 10000
Value of timeout for remote rpc connect
/Experiment/Transition timeout
- Type: INT
- Default: 120000
Value of timeout for transition
/Experiment/Prevent start on alarms
- Type: BOOL
- Default: "n"
Setting this key true will prevent the run from starting if an alarm is true.
/Experiment/Prevent start on required program
- Type: BOOL
- Default: "n"
Setting this key true will prevent the run from starting if one of the required clients is not running.
/Experiment/Status items subtree
/Experiment/Start-Stop Buttons
- Type: BOOL
- Default: "y"
/Experiment/Pause-Resume Buttons
- Type: BOOL
- Default: "n"
/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 Edit-on-start Parameters for details.
/Experiment/Parameter Comments subtree
This optional subdirectory may contain user-defined parameter comments that give more information about the Edit-on-start Parameters.
/Experiment/Lock when running subtree
This optional subdirectory contains user-defined links to ODB parameters to prevent them being changed when the run is in progress. See Lock when running for details.
/Experiment/Security subtree
This optional subtree is created when the odbedit commands passwd or webpasswd are issued. It enables a user to set up security features. See Security
/Experiment/Security/Password
- Type: STRING
- Default:
Contains the encrypted password. Key is created when odbedit command passwd is issued. See security for details.
/Experiment/Security/Allowed hosts subtree
This subtree is created when odbedit command passwd is issued. When created, this subtree is empty. It may contain names of remote hosts allowed to have free access (i.e. without password) to the current experiment. See allowed hosts.
/Experiment/Security/Allowed programs subtree
This subtree is created when odbedit command passwd is issued. When created, this subtree is empty. It may contain names of clients allowed to have free access (i.e. without password) to the current experiment. See allowed clients.
/Experiment/Security/Web Password
- Type: STRING
- Default:
If web access restriction has been set up, this key will contain an encrypted password for Web server access. Key is created when odbedit command webpasswd is issued.
If this key is present, the user will be requested to provide the "Web Password" when accessing the requested experiment in "Write Access" mode. The "Read Only Access" mode is still available to all users.