/History ODB tree

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• mhttpd History Page
• /Logger ODB tree
• /Logger/History subtree

Purpose

The ODB /History tree contains information related to the History System.

Creating the /History tree

The /History ODB tree is created by mlogger. A single group named "Default"is created containing the trigger rate for the "Trigger" equipment. The user customizes the /History tree by adding new panels as needed from the mhttpd History Page. Much of the /History tree is created and used by the History System and need not concern the user.

Example of /History tree

The system created the following /History tree using the /Equipment/INFO tree. The history tags are derived from the variable "Names" (if present) in the Settings subtree. MIDAS-history is selected.

New panels in the /History/Display subtree are added from the History Page (see example below).

[local:pol:S]/History>ls -lr
Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
History                         DIR
   LoggerHistoryChannel        STRING  1     32    24h  0   RWD
   DisableTags                 BOOL    1     4     1h   0   RWD  n
   Display                     DIR
       Default                 DIR
           Trigger rate        DIR
               Variables       STRING  2     64    1h   0   RWD
                                       [0]             System:Trigger per sec.
                                       [1]             System:Trigger kB per sec.
               Time Scale      STRING  1     32    1h   0   RWD  1h
               Factor          FLOAT   2     4     1h   0   RWD
                                       [0]             1
                                       [1]             1
               Offset          FLOAT   2     4     1h   0   RWD
                                       [0]             0
                                       [1]             0
               Timescale       STRING  1     32    1h   0   RWD  1h
               Zero ylow       BOOL    1     4     1h   0   RWD  y
               Show run markersBOOL    1     4     1h   0   RWD  y
               Log axis        BOOL    1     4     24h  0   RWD  n
               Show values     BOOL    1     4     24h  0   RWD  n
               Sort vars       BOOL    1     4     24h  0   RWD  n
               Show old vars   BOOL    1     4     24h  0   RWD  n
               Minimum         FLOAT   1     4     24h  0   RWD  -inf
               Maximum         FLOAT   1     4     24h  0   RWD  inf
   Links                       DIR
       System                  DIR
           Trigger per sec. -> /Equipment/Trigger/Statistics/Events per sec.
                               DOUBLE  1     8     16h  1   RWD  0
           Trigger kB per sec. -> /Equipment/Trigger/Statistics/kBytes per sec.
                               DOUBLE  1     8     16h  1   RWD  0
   Events                      DIR
       101                     STRING  1     7     1h   0   RWD  System
       0                       STRING  1     16    24h  0   RWD  Run transitions
       3                       STRING  1     5     24h  0   RWD  INFO
   Tags                        DIR
       101                     STRING  3     96    1h   0   RWD
                                       [0]             System
                                       [1]             10[1] Trigger per sec.
                                       [2]             10[1] Trigger kB per sec.
       0                       STRING  3     96    1h   0   RWD
                                       [0]             Run transitions
                                       [1]             6[1] State
                                       [2]             6[1] Run number
       3                       STRING  25    96    24h  0   RWD
                                       [0]             INFO
                                       [1]             9[1] Data still buffered
                                       [2]             9[1] Num SIS LNE events
                                       [3]             9[1] LNE count from SIS
                                       [4]             9[1] LNE preset value
                                       [5]             9[1] number of bins
                                       [6]             9[1] data bytes code
                                       [7]             9[1] num enabled channels
                                       [8]             9[1] discard first bin
                                       [9]             9[1] discard first cycle
                                       [10]            9[1] not used
                                       [11]            9[1] Scan type code
                                       [12]            9[1] Number good cycles
                                       [13]            9[1] Number supercycles
                                       [14]            9[1] Cycle num within supercycle
                                       [15]            9[1] Sweep number
                                       [16]            9[1] Num cycles skipped
                                       [17]            9[1] Num cycles histogrammed
                                       [18]            9[1] DAC Increment number
                                       [19]            9[1] DAC Set Value (volts)
                                       [20]            9[1] DAC Readback (volts)
                                       [21]            10[1] SC Sum ch17
                                       [22]            10[1] SC Sum ch18
                                       [23]            10[1] SC Sum ch19
                                       [24]            10[1] SC Sum ch20
   Display Settings            DIR
       Width Group            STRING  1     256   24h  0   RWD  Small

Keys in the /History ODB tree

LoggerHistoryChannel

• Type: STRING
• Default: "MIDAS"

This key in the /History ODB tree selects the history-logging-channel to be used for saving the History data. The history-logging-channel determines the history driver to be used for saving the history data (see also Type key).

If LoggerHistoryChannel is blank, the first Active channel will be used.

DisableTags

• Type: BOOL
• Default: "n"

This key in the /History ODB tree only used for MIDAS-history, and is not used by the other history drivers.

Set this key in the /History ODB tree to "y" if reading the history tags directly from the history files. Set to "n" to read the history tags from the ODB. If this key is set to "y" the Tags subtree (if present) will be deleted.

See History Tag names.

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CreateOldTags

• Type: BOOL
• Default: "n"

This key in the /History ODB tree only used for MIDAS-history, and is not used by the other history drivers.

If this key is set to "y", it will force creation of the Tags subtree using the old format. See Tag names.

This key is optional and may not be present in recent versions.

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MaxDisplayEvents

• Type: INT
• Default: 20

This key in the /History ODB tree is used by mhttpd to set the maximum number of events displayed on the mhttpd history page (is this correct??)

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MaxDisplayTags

• Type: INT
• Default: 20

This key in the /History ODB tree is used by mhttpd to set the maximum number of tags (is this correct??)

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PerVariableHistory (obsolete)

• Type: INT
• Default: "n"

This key in the /History ODB tree is OBSOLETE and should be deleted from the ODB if using a recent version of MIDAS. A message will be printed to this effect.

It has been replaced by PerVariableHistory.

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Links subtree

• Type: DIR

This subtree in the /History ODB tree is created by mlogger. It is used for Virtual History Events. The user may create links under this subtree to any ODB variable to record the history of that variable as a virtual history event.

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System subtree

• Type: DIR

This subtree in the Links subtree is created by mlogger if an equipment named "Trigger" is present.

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Trigger per sec.

• Type: LINK

This link in the System subtree is created by mlogger if an equipment named "Trigger" is present. Trigger per sec. is linked to the key /Equipment/Trigger/Statistics/Events per sec..

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Trigger kB per sec.

• Type: LINK

This link in the System subtree is created by mlogger if an equipment named "Trigger" is present. Trigger kB per sec. is linked to the key /Equipment/Trigger/Statistics/kBytes per sec..

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Tags subtree

• Type: DIR

This subtree in the /History ODB tree is used by the system for private data storage for the MIDAS-history driver, and is not used for ODBC-history or SQLITE-history (see history drivers).

How about MYSQL or FILE history drivers ??

Are the following statements all true??

• This subtree will be deleted for MIDAS-history with old-style tags.
• This subtree will be deleted if DisableTags is set.
• If CreateOldTags is set, this subtree will be created with the old format.

If MIDAS-history is enabled, and the Equipment key /Equipment ODB tree#Log history is set for one or more Equipments, this subtree is created by mlogger. It contains history tags created by mlogger for each equipment set to /Equipment ODB tree#Log history.

Is the key /Equipment/Settings/PerVariableHistory key an optional key created by the user?

If the global PerVariableHistory key is set or the PerVariableHistory key in the /Equipment/Settings subtree of that equipment, then tags for that Equipment will be created automatically by mlogger. The names of the tags will be taken from /Equipment/Settings/Names if present, otherwise default tag names will be created.

The contents of the event will then be completely copied into the MIDAS-history files, using the definition of the event as tag names for every element of the event.

Display subtree

• Type: DIR

This subtree in the /History ODB tree is created by the Midas web server mhttpd when the History button on the main status page is pressed. It contains parameters used by the system to control the History panels display on the mhttpd history page. It contains a subtree for each defined History panel.

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<panel-name> subtree

• Type: DIR

This subtree in the Display subtree is named for the panel on the mhttpd History page, and contains information to define the contents of this panel. In the example, only one panel is defined, named Default. If there is more than one panel defined, there will be other panel subtrees present with different panel names.

The <panel-name> subtrees are created when the New button is pressed on the History Page. Panels can also be grouped under a panel group name. In the following example, a number of panel group names are defined:

[local:deap:Running]/>ls /history/display/
Default
Temperatures
SCBs
UPSs
CDU
VME
Rates
etc.

Each panel group contains a number of panels, e.g.

[local:deap:Running]/>ls /history/display/UPSs
UPS
UPS1
UPS2
UPS3

Each of these is a <panel-name> subtree containing the information required for the History Page to display the panel. The history page for this system is shown in Figure 1 on the History Page.

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Display Settings subtree

• Type: DIR

This subtree in the /History ODB tree is created by the Midas web server mhttpd when the History button on the main status page is pressed. It contains parameters used by the system to control the History Display on the mhttpd History page.

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Events subtree

This subtree in the /History tree is used by the system for private data storage for the MIDAS-history driver, and is not used by any other history driver.

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Images subtree

This subtree in the /History tree is used to specify which webcams should be logged as part of the Image History system.

You should create a subdirectory for each webcam you want to record, and each subdirectory should have the keys listed below. Note that mlogger creates /History/Images/Demo/ as an example, and you may find it easiest to edit/copy that subdirectory rather than creating a new one from scratch.

• Name (string): Name of this camera
• Enabled (boolean): Whether to enable readout of camera
• URL (string): URL to fetch an image from the camera
• Period (int): Time period in seconds to fetch a new image
• Storage hours (int): Number of hours to store the images (0 for infinite)
• Extension (string): Image file extension, usually ".jpg" or ".png"
• Timescale (string): Initial horizontal time scale to show on the webpage (e.g. 8h for 8 hours, 30m for 30 minutes)

The following keys are also present in each subdirectory, and are used internally by the logger:

• Last fetch (int)
• Error interval (s) (int)
• Last error (int)

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