/Equipment ODB tree

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Purpose

The ODB /Equipment tree contains user and system information related to a frontend.

Creating the /Equipment tree

An empty /Equipment tree will be created by mlogger.

If an Equipment is defined in Frontend user code, the first time the frontend is run, if that equipment does not exist in the ODB, it will be created (using db_create_record) in the ODB as a subtree under the /Equipment tree with the values supplied in the Frontend user code.

Example of /Equipment tree

The following is an example of the /Equipment tree from an experiment obtained with the odbedit ls command listing all the defined equipments in the experiment :

[local:pol:S]Settings>ls /Equipment -l
Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
POL_ACQ                         DIR
Scaler                          DIR
Trigger                         DIR
VME                             DIR
SisPulser                       DIR
INFO                            DIR
HISTO                           DIR

The following is a listing of one of the equipments in the /Equipment tree shown above :

[local:pol:S]Settings>ls /Equipment/info/ -lr                
Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
INFO                            DIR
   Common                      DIR
       Event ID                WORD    1     2     9h   0   RWD  3
       Trigger mask            WORD    1     2     9h   0   RWD  8
       Buffer                  STRING  1     32    9h   0   RWD  SYSTEM
       Type                    INT     1     4     9h   0   RWD  1
       Source                  INT     1     4     9h   0   RWD  0
       Format                  STRING  1     8     9h   0   RWD  MIDAS
       Enabled                 BOOL    1     4     9h   0   RWD  y
       Read on                 INT     1     4     9h   0   RWD  257
       Period                  INT     1     4     9h   0   RWD  100
       Event limit             DOUBLE  1     8     9h   0   RWD  0
       Num subevents           DWORD   1     4     9h   0   RWD  0
       Log history             INT     1     4     2h   0   RWD  60
       Frontend host           STRING  1     32    9h   0   RWD  lxpol.triumf.ca
       Frontend name           STRING  1     32    9h   0   RWD  pol_fevme
       Frontend file name      STRING  1     256   9h   0   RWD  pol_fevme.cxx
       Status                  STRING  1     256   9h   0   RWD  pol_fevme@lxpol.triumf.ca
       Status color            STRING  1     32    9h   0   RWD  #00FF00
       Hidden                  BOOL    1     4     9h   0   RWD  n

   Variables                   DIR
       DBUG                    FLOAT   9     4     2h   0   RWD
                                       [0]             0
                                       [1]             101
                                       [2]             10201
                                       [3]             10201
                                       [4]             101
                                       [5]             2
                                       [6]             4
                                       [7]             1
                                       [8]             1

       CYCL                    FLOAT   15    4     2h   0   RWD
                                       [0]             1
                                       [1]             9800
                                       [2]             98
                                       [3]             100
                                       [4]             9
                                       [5]             98
                                       [6]             9800
                                       [7]             9
                                       [8]             9
                                       [9]             8.9682
                                       [10]            8.966
                                       [11]            0.0504
                                       [12]            0
                                       [13]            8.7906
                                       [14]            0
       SUMS                    DOUBLE  4     8     2h   0   RWD
                                       [0]             0
                                       [1]             50002
                                       [2]             0
                                       [3]             0

   Statistics                  DIR
       Events sent             DOUBLE  1     8     8h   0   RWD  176
       Events per sec.         DOUBLE  1     8     8h   0   RWD  0
       kBytes per sec.         DOUBLE  1     8     8h   0   RWD  0

   Settings                    DIR
       Names DBUG              STRING  12    32    9h   0   RWD  
                                       [0]             Data still buffered
                                       [1]             Num SIS LNE events
                                       [2]             LNE count from SIS
                                       [3]             LNE preset value
                                       [4]             number of bins
                                       [5]             data bytes code
                                       [6]             num enabled channels
                                       [7]             discard first bin
                                       [8]             discard first cycle
                                       [9]             not used
                                       [10]            not used
                                       [11]            not used
       Names CYCL              STRING  15    32    9h   0   RWD  
                                       [0]             Scan type code
                                       [1]             Number good cycles
                                       [2]             Number supercycles
                                       [3]             Cycle num within supercycle
                                       [4]             Sweep number
                                       [5]             Num cycles skipped
                                       [6]             Num cycles histogrammed
                                       [7]             DAC Increment number
                                       [8]             DAC Set Value (volts)
                                       [9]             DAC Readback (volts)
                                       [10]            ADC1 Average
                                       [11]            ADC2 Average
                                       [12]            ADC3 Average
                                       [13]            ADC4 Average
                                       [14]            spare

       Names SUMS              STRING  4     32    9h   0   RWD  
                                       [0]             SC Sum ch17
                                       [1]             SC Sum ch18
                                       [2]             SC Sum ch19
                                       [3]             SC Sum ch20

Keys in the /Equipment ODB tree

<equipment-name> subtree

This subtree in the /Equipment ODB tree The /Equipment ODB tree will be named for an Equipment defined in the Frontend user code. No two subtrees in an experiment can have the same name. An <equipment-name> subtree will be present for every defined equipment in all the frontend(s) run on the experiment.

This subtree will be created (if it does not already exist) the first time the defining frontend is run, and the initial values set are defined in the Equipment List Parameters in the Frontend user code that defines this particular equipment.

Note: that if these parameters are later changed in the ODB, they will not be overwritten by the values in the frontend, if the frontend is restarted.

---

Common subtree

This subtree in an /Equipment/<equipment-name> subtree contains the parameters used by the system to process the Equipment.

The initial values of the Common parameters are set when this tree is created (see initial values).

---

Event ID

• Type: WORD
• Default: See initial value

This key in the Common subtree contains the Event ID of this equipment. See EventID for details.

---

Trigger mask

• Type: WORD
• Default: See initial value

This key in the Common subtree contains the Trigger mask of this equipment. See TriggerMask for details.

---

Buffer

• Type: STRING
• Default: See initial value

This key in the Common subtree contains the Buffer parameter of this equipment. See Buffer for details. For Events that are to be logged as banks, Buffer is set to "SYSTEM".

---

Type

• Type: INT
• Default: See initial value

This key in the Common subtree contains the Type of this equipment. See Type for details. The Type is one of the defined Equipment Flags.

---

Source

• Type: INT
• Default: See initial value

This key in the Common subtree contains the Interrupt or Event Source of this equipment. See Source for details.

---

Format

• Type: STRING
• Default: See initial value

This key in the Common subtree contains the data format used for generating the event of this equipment. See Format for details.

---

Enabled

• Type: BOOL
• Default: See initial value

This key in the Common subtree indicated whether this equipment is active. See Enabled for details.

---

Read on

• Type: INT
• Default: See initial value

This key in the Common subtree specifies when the read-out of an event occurs or is enabled. It is set to one or a combination of ReadOn Flags. See Read on for details.

---

Period

• Type: INT
• Default: See initial value

This key in the Common subtree specifies the time interval or time-out (units are milliseconds). See Period for details.

---

Event limit

• Type: DOUBLE
• Default:

This key in the Common subtree specifies the time interval or time-out. See Event limit for details.

---

Num subevents

• Type: DWORD
• Default: See initial value

This key in the Common subtree enables the super-event capability. See Number of subevents for details.

---

Log history

• Type: INT
• Default: See initial value

This key in the Common subtree enables the History System for this equipment. See Log History for details. A value of 0 disables history logging. This parameter also controls how frequently the history events are generated.

---

Frontend host

• Type: STRING
• Default:

This key in the Common subtree contains the name of the Frontend host running the Frontend user code that defines this particular equipment. It is filled by the system.

---

Frontend name

• Type: STRING
• Default:

This key in the Common subtree contains the Frontend name defined in the Frontend user code that defines this particular equipment. It is filled by the system.

---

Frontend file name

• Type: STRING
• Default:

This key in the Common subtree contains the filename of the Frontend user code that defines this particular equipment. It is filled by the system.

---

Status

• Type: STRING
• Default:

This key in the Common subtree contains the combination of Frontend name and Frontend host Frontend host that define this particular equipment. It is filled by the system and used by the Status Page#mhttpd status page.

---

Status color

• Type: STRING
• Default: "#00FF00"

This key in the Common subtree contains a colour code to be used for the display of this equipment on the Status Page#mhttpd status page.

---

Hidden

• Type: BOOL
• Default: "n"

This key in the Common subtree if set to "y" will prevent the display of this equipment on the Status Page#mhttpd status page.

---

Write cache size

• Type: INT
• Default: 10000000

This key in the Common subtree controls the size of a cache (in bytes) that the midas frontend framework will use to buffer events before sending them to other clients (like the Logger). Optimising the size of the cache may improve the performance of your frontend, especially if you're sending large events. The minimum (and default) value is 10MB (10000000 bytes).

---

Variables subtree

• Type: DIR

This is a subtree in the /Equipment ODB Tree.

If either

• the Read on parameter contains the RO_ODB flag or
• Log history is non-zero, i.e. History logging is enabled

the event data will be copied to the ODB and listed in this subtree.

In that case, this subtree will contain array(s) of event data named for the bankname(s) in the readout function (see Frontend user code#Event Readout routine. See example above.

---

Statistics subtree

• Type: DIR

This subtree in the /Equipment ODB Tree contains statistics written by the system.

---

Events sent

• Type: DOUBLE

This key in the Statistics subtree contains the number of events of Event ID sent. It is filled by the system and used for display on the Status Page#mhttpd status page. See example above.

---

Events per sec

• Type: DOUBLE

This key in the Statistics subtree contains the number of events of Event ID sent per second. It is filled by the system and used for display on the Status Page#mhttpd status page.

---

kBytes per sec

• Type: DOUBLE

This key in the Statistics subtree contains the number of kBytes per second for events of Event ID sent. It is filled by the system and used for display on the Status Page#mhttpd status page.

---

Settings subtree

• Type: DIR

This subtree in the /Equipment ODB Tree contains user-defined settings, some of which may be used by the system. Any values defined in this subtree will appear in experim.h files.

---

Names and Names <variable>

• Type: STRING (ARRAY)

These optional key(s) in the Settings subtree are used to define the names of variables in the Variables subtree.

Say you have an entry in Variables called "CURR" that contains 3 floats. You can then specify the names of these 3 elements here (i.e. if you're storing the current of 3 channels, you use Names to define the name of each channel).

You can either create a key called "Names" that will apply to all Variables, or create separate keys for each Variable (e.g. "Names CURR").

The Names array(s) (if present) will be used by the Equipment Page, and by the History System to generate tags. See example above.

---

Unit <variable>

• Type: STRING

These optional key(s) in the Settings subtree are used to define the units of variables in the Variables subtree.

Say you have an entry in Variables called "CURR". You can specify that the current is measured in mA by creating a key called "Unit CURR" and setting it to "mA".

These keys (if present) will be used by the Equipment Page.

---

Format <variable>

• Type: STRING

These optional key(s) in the Settings subtree are used to define the formatting of variables in the Variables subtree.

A value of "%f2" for example shows a value with two digits after the period. A complete list of formats is listed on the MIDAS custom page documentation.

These keys (if present) will be used by the Equipment Page.

---

Editable

• Type: STRING

This optional key in the Settings subtree is used to by the Equipment Page to decide whether to show an "editable" interface for each variable, or just show the present value.

It should contain a comma-separated list of Variables that are allowed to be edited on the Equipment Page.

---

Grid display

• Type: BOOLEAN

This key in the Settings subtree is used to by the Equipment Page to define the display mode of equipment variables. If false, each variable is shown on a separate row. This make sense for example for environment variables where one has an array of temperatures, another array for pressures et.

If true, the display switches to grid mode. This shows now one channel per row. That makes sense for equipment which has several parameters per channel. An example is a high voltage channel which has attributes like voltage, current, trip voltage, temperature, status. The grid display is then more compact and shows all attributes of a channel next to each other.

The equipment page code tries to 'guess' the grid mode if this setting is not present in the ODB. It turns it on if it finds a number of arrays under 'variables' with exactly the same length, assuming that these then are channel attributes. If at least one array has a different length, the mode is turned off. It can always be overwritten by changing the ODB setting later.