Difference between revisions of "Glossary"

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{{Pagelinks}}
 
{{Pagelinks}}
 
= Alphabetical Index =
 
= Alphabetical Index =
<div style="column-count:19;-moz-column-count:19;-webkit-column-count:19">
+
<div style="column-count:19;-moz-column-count:26;-webkit-column-count:26">
 
; [[#A|A]]
 
; [[#A|A]]
 
; [[#B|B]]
 
; [[#B|B]]
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; <span style="color:red; font-weight: normal">G</span>
 
; <span style="color:red; font-weight: normal">G</span>
 
; [[#H|H]]
 
; [[#H|H]]
; <span style="color:red; font-weight: normal">I - N</span>
+
; <span style="color:red; font-weight: normal">I J K L</span>
 +
; [[#M|M]]
 +
; <span style="color:red; font-weight: normal">N</span>
 
; [[#O|O]]
 
; [[#O|O]]
 
; <span style="color:red; font-weight: normal">P</span>
 
; <span style="color:red; font-weight: normal">P</span>
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<div id="A"></div>
 
<div id="A"></div>
 
'''A'''  
 
'''A'''  
 +
;Alias Button (Link)
 +
: User-created button on the Webserver [[Status Page]] providing a symbolic link to any desired ODB location or to an external webpage. Created by user via the [[/Alias ODB tree]].
 
  <div id="Application"></div>
 
  <div id="Application"></div>
 
;Application
 
;Application
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--------------- <div id="C"></div>
 
--------------- <div id="C"></div>
'''C''' <div id="Client"></div>
+
'''C''' <div id="Clients"></div>
 
;Client  
 
;Client  
: A MIDAS Client is an [[#Application]] provided by the MIDAS system or (partially) written by the user (e.g. a [[#Frontend]]) that links with the MIDAS libraries and runs under the MIDAS system to allow the user to run a MIDAS [[#Experiment]]. MIDAS clients can be Local or Remote.
+
: A MIDAS Client is an [[#Application]] provided by the MIDAS system or (partially) written by the user (e.g. a [[#Frontend]]) that links with the MIDAS libraries and runs under the MIDAS system to allow the user to run a MIDAS [[#Experiment]]. MIDAS clients can be ''Local'' or ''Remote''.
 
:; Local
 
:; Local
 
:: A MIDAS client than runs on the [[#Host|Experiment Host]].
 
:: A MIDAS client than runs on the [[#Host|Experiment Host]].
 
:;Remote
 
:;Remote
 
:: A MIDAS client than runs on a [[#Host|Remote Host]].
 
:: A MIDAS client than runs on a [[#Host|Remote Host]].
 +
;Custom :
 +
:; Button (Link) : User-created button on the Webserver [[Status Page]] providing access to a ''custom page''. Custom links are created through the [[/Custom ODB tree]].
 +
;Customscript Button
 +
User-created button on a Webserver [[Custom Page]] which executes a script when pressed. Created by user via the [[/Customscript ODB tree]].
 +
:; Page : User-created [[Custom Page]] accessed from the  Webserver [[Status Page]]. Created when the standard Webserver pages do not fully meet the user's requirements. It usually includes data from the ODB displayed according to the user's preference.
  
 
--------------- <div id="D"></div>
 
--------------- <div id="D"></div>
 
'''D'''
 
'''D'''
;Data Bank : data in an ''event'' in a particular format
+
;Data :
 +
:;Archiver : ''Application'' [[Lazylogger]] can copy the logged data files to another storage device.
 +
<div id="Data Bank"></div>
 +
:;Bank : data in an [[#Event]] with a bank header followed by data in a particular ''data format''
 +
<div id="Data Format"></div>
 +
:;Format : [[Event Structure|Data Formats]]  "MIDAS" (a variable-length format) and "FIXED" are written by a [[#Frontend]]. The format used is determined by the [[#Equipment List]]. The ''data logger'' can convert MIDAS/FIXED formats to "ROOT" format.
 +
:;Logger : [[Data Logger]] ''application'' [[mlogger]] serves multiple purposes related to data logging including logging experimental data to a storage device
 
;Device : a Hardware module (e.g. a scaler) to be accessed by software called a ''device driver''.
 
;Device : a Hardware module (e.g. a scaler) to be accessed by software called a ''device driver''.
;Driver : (also [[MIDAS Driver Library|device driver]]). Software that allows access to a particular hardware module.
+
;Driver : Also [[MIDAS Driver Library|Device Driver]]. Software that allows access to a particular hardware module.
  
 
----------------- <div id="E"></div>
 
----------------- <div id="E"></div>
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;Environment Variables
 
;Environment Variables
 
: Certain [[Environment Variables]] are used by MIDAS. Only [[Environment Variables#MIDASSYS|MIDASSYS]] is required.
 
: Certain [[Environment Variables]] are used by MIDAS. Only [[Environment Variables#MIDASSYS|MIDASSYS]] is required.
;Equipment : usually ''Software equipment''
+
;Equipment : see [[#Software Equipment]]
:;Hardware : Hardware Devices (e.g. a set of scalers) grouped together for convenience of data readout by a ''Software Equipment''.
+
:;Hardware : Hardware Devices (e.g. a set of scalers) grouped together for convenience of data readout by a [[#Software Equipment]].
:; Software : usually called "Equipment". A single or a collection of sub-tasks meant to collect and regroup logical or physical data (read from a ''Hardware Equipment'') under a single and uniquely identified ''event''. '''Software Equipments''' are usually found in [[Frontend Operation#Frontends| Frontends]], and are reflected in the [[/Equipment ODB tree]].
+
:;Flag : [[Equipment Flags]] are used in the Equipment Type field in the EQUIPMENT structure of a frontend. The selected flag determines the Equipment Type.
 
+
<div id="Equipment List"></div>
;Event : a collection of data sent into the data stream by an ''Equipment'', usually in the form of ''data banks''.
+
:;List : declaration of a [[#Software Equipment]] in a [[Frontend Operation#Frontends| Frontend]] using the EQUIPMENT structure defined in midas.h in the MIDAS package.  When the frontend is started, the values in the ''equipment list'' for each defined Equipment will be written to the [[/Equipment ODB tree]].
;Experiment : a MIDAS experiment defined on the [[#Host|Experiment Host]]. Optionally defined in the [[exptab]] file.
+
<div id="Software Equipment"></div>
 +
:; Software : usually called simply "''equipment''". A single or a collection of sub-tasks meant to collect and regroup logical or physical data (read from a ''hardware equipment'') under a single and uniquely identified [[#Event]].  Each '''(Software) Equipment''' is defined using an ''equipment list'' in a [[#Frontend]].
 +
:;ReadOn Flags : [[ReadOn Flags]] are used in the "Read On" field of the [[#Equipment List|equipment declaration]] to specify when the read-out of an event occurs.
 +
:;Trigger : the event is triggered according to the ''equipment type''.
 +
::;Manual : A button is created automatically on the Webserver [[Status Page]] when an equipment with the ''equipment flag''  EQ_MANUAL_TRIGGER is present. A manually-triggered event is sent when button is pressed.  
 +
:; Type : Equipment Type determined by the ''equipment flag'' in the ''equipment list''.
 +
<div id="Event"></div>
 +
;Event : a collection of data sent into the data stream by a Frontend [[#Software Equipment|Equipment]], usually in the form of [[#Data Bank]]s. The Event ID, Event Format, Event Buffer are determined by the [[#Equipment List]] for that event.
 +
:;Format : see [[#Data Format]]
 +
:;Buffer : Buffer to contain the ''events''. The event buffer used (usually "SYSTEM") is determined by a parameter in the [[#Equipment List]] for that event.
 +
:;Structure :Event consists of a header and a data area containing data banks. See [[Event Structure]].
 +
<div id="Experiment"></div>
 +
;Experiment : a MIDAS experiment must be defined in order to run the MIDAS DAQ system. It is defined on the [[#Host|Experiment Host]] and is usually defined in the [[exptab]] file, which may define several MIDAS experiment.
 
:; Host : see [[#Host]]
 
:; Host : see [[#Host]]
  
 
---------------- <div id="F"></div>
 
---------------- <div id="F"></div>
'''F'''
+
'''F''' <div id="Frontend"></div>
;Frontend : A MIDAS application built by the user which usually has access to ''hardware equipment'' in use by the experiment. Includes Frontend Code linked with a fixed framework ''mfe.c'' to form a [[Frontend Operation#Frontends| Frontend]].
+
;Frontend : A MIDAS ''application'' built by the user which usually has access to ''hardware equipment'' in use by the experiment. Includes Frontend Code linked with a fixed framework <span style="color:navy ; font-style:italic; ">mfe.c</span> to form a [[Frontend Operation#Frontends| Frontend]]. A slow-control frontend is used by the [[Slow Control System]].  
:;Code : The ''frontend code'' is the user-written part of the frontend application (e.g. ''frontend.c'') describing sequence of actions to acquire the hardware data. See '''Frontend''' above.
+
:;Code : The ''frontend code'' is the user-written part of the ''frontend'' application (e.g. <span style="color:navy ; font-style:italic; ">frontend.c</span>) describing sequence of actions to acquire the hardware data.  
 +
:;Equipment : See [[#Software Equipment]]
  
 
------------ <div id="H"></div>
 
------------ <div id="H"></div>
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:; Remote : a ''remote host'' is a host computer on which (remote) MIDAS client(s) run which connect to the MIDAS experiment on the [[#Host|Experiment Host]]. See [[Quickstart Linux]] to set up a remote host.
 
:; Remote : a ''remote host'' is a host computer on which (remote) MIDAS client(s) run which connect to the MIDAS experiment on the [[#Host|Experiment Host]]. See [[Quickstart Linux]] to set up a remote host.
  
 +
------------ <div id="M"></div>
 +
'''M'''
 +
 +
; MSCB
 +
: [https://midas.psi.ch/mscb/|MIDAS Slow Control Bus] can be used for [[#Slow Control]]. Optionally can be built into MIDAS DAQ System.
 +
 
------------ <div id="O"></div>
 
------------ <div id="O"></div>
 
'''O'''  
 
'''O'''  
 
; ODB
 
; ODB
 
: The [[Midas Core#Online Database (ODB)|Online Data Base (ODB)]] contains all the information needed for an experiment. It can be accessed and/or edited using the [[ODB Page]] of the [[#Web Server]] or [[odbedit]] application.
 
: The [[Midas Core#Online Database (ODB)|Online Data Base (ODB)]] contains all the information needed for an experiment. It can be accessed and/or edited using the [[ODB Page]] of the [[#Web Server]] or [[odbedit]] application.
:; Directory : The ODB is structured as a "directory".  '''ODB Directory''' is used as alternative name for an ODB Tree.
+
:; Directory : The ODB is structured as a "directory".  ''ODB directory'' is used as an alternative for ''ODB tree''.
:; Key : Data in the ODB are contained in Key/Data pairs in an ODB Tree or subtree. ODB Keys can be of various Types. In the Path <span style="color: purple; font-style:italic;">/Logger/write data</span>, the key is <span style="color: purple; font-style:italic;">write data</span>.  
+
:; Key : Data in the ODB are contained in Key/Data pairs in an ''ODB tree'' or ''subtree''. ODB Keys can be of various Types. In the Path <span style="color: purple; font-style:italic;">/Logger/write data</span>, the key is <span style="color: purple; font-style:italic;">write data</span>.  
 
::;Type: ODB Key Types can be one of BYTE,CHAR,WORD,SHORT,DWORD,INT,BOOL,FLOAT,DOUBLE,STRING
 
::;Type: ODB Key Types can be one of BYTE,CHAR,WORD,SHORT,DWORD,INT,BOOL,FLOAT,DOUBLE,STRING
 
::;Data: Data is contained in Key/Data pairs in the ODB. Use the [[#Web Server]] or [[odbedit]] application to view the Key/Data pairs.
 
::;Data: Data is contained in Key/Data pairs in the ODB. Use the [[#Web Server]] or [[odbedit]] application to view the Key/Data pairs.
 
:; Path : "address" used to access an ODB Key using the directory structure of the ODB, e.g. <span style="color: purple; font-style:italic;">/Logger/write data</span>. Upper/Lower Case is ignored.
 
:; Path : "address" used to access an ODB Key using the directory structure of the ODB, e.g. <span style="color: purple; font-style:italic;">/Logger/write data</span>. Upper/Lower Case is ignored.
:; Subdirectory : Alternative name to ODB Subtree used by some authors
+
:; Subdirectory : Alternative to ''ODB Subtree''
:; Subtree : An ODB subtree starts at a lower level than an ODB Tree, e.g. <span style="color: purple; font-style:italic;">/Experiment/Security</span> subtree.
+
:; Subtree : An ODB subtree starts at a lower level than an ODB Tree, e.g. <span style="color: purple; font-style:italic;">/Experiment/Security</span> subtree. May also be called a ''subdirectory''.
:; Tree : data in the ODB are structured in a tree form with each "directory" dealing with a specific section of the acquisition. An ODB Tree starts at the top level, e.g. <span style="color: purple; font-style:italic;">/Equipment</span> ODB tree.
+
:; Tree : data in the ODB are structured in a tree form with each "directory" dealing with a specific section of the acquisition. An ODB Tree starts at the root level "/", e.g. <span style="color: purple; font-style:italic;">/Equipment</span> ODB tree. May alternatively be called an ODB ''directory''.
  
 
------------ <div id="R"></div>
 
------------ <div id="R"></div>
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;Run
 
;Run
:  A ''run'' starts when the MIDAS system receives a Start Transition , and continues until it receives a Stop transition
+
:  A ''run'' starts when the MIDAS system receives a Start ''transition'' , and continues until it receives a Stop ''transition''.
 
<div id="Run State"></div>
 
<div id="Run State"></div>
 
:;State : MIDAS defines three ''run states'': '''Stopped, Paused''' and '''Running'''. See  [[Run States and Transitions]].  
 
:;State : MIDAS defines three ''run states'': '''Stopped, Paused''' and '''Running'''. See  [[Run States and Transitions]].  
  
 
------------ <div id="S"></div>
 
------------ <div id="S"></div>
'''S''' <div id="Shared Memory"></div>
+
'''S'''
 +
;Script Button
 +
User-created button on the Webserver [[Status Page]] which executes a script when pressed. Created by user via the [[/Script ODB tree]].
 +
<div id="Shared Memory"></div>
 
;Server :  
 
;Server :  
:; MIDAS : A remote procedure call (RPC) server [[mserver]] available for '''remote''' access to a MIDAS experiment.
+
:; MIDAS : A remote procedure call (RPC) server [[mserver]] available for ''remote'' access to a MIDAS experiment.
 
::; Web : See [[#Web Server]]
 
::; Web : See [[#Web Server]]
 
;Shared Memory
 
;Shared Memory
: The MIDAS shared memory regions in RAM are called '''buffers''', and managed by the [[Midas Core#the buffer manager|MIDAS Buffer Manager]]. MIDAS uses shared memory for the ODB, System Messages, Data buffer, Alarms and History systems. The MIDAS '''shared memory saved files''' (.*.SHM) for an experiment reside on the [[#host|Experiment host]] at the path given by the Environment Variable [[Environment Variables#MIDASSYS|MIDASSYS]].
+
: The MIDAS shared memory regions in RAM are called ''buffers'', and managed by the [[Midas Core#the buffer manager|MIDAS Buffer Manager]]. MIDAS uses shared memory for the ODB, System Messages, Data buffer, Alarms and History systems.  
 +
:;Saved Files :The MIDAS ''shared memory saved files'' (.*.SHM) for an experiment reside on the [[#host|Experiment host]] at the path given by the Environment Variable [[Environment Variables#MIDASSYS|MIDASSYS]].
 +
<div id="Slow Control"></div>
 +
;Slow Control system
 +
: Controls and monitors hardware that is not time-critical (e.g. high voltage modules, temperature sensors). See [[Slow Control System]].  
 
;State
 
;State
 
: See [[#Run State]]
 
: See [[#Run State]]
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'''T'''
 
'''T'''
 
;Task
 
;Task
: a MIDAS client application. '''Task''' and '''Utility''' are used in this document as alternatives to '''Application''' by different authors.
+
: a MIDAS client application. "Task" and "utility" are used in this document as alternatives to ''"application"'' by different authors.
 
;Transition
 
;Transition
 
: A transition occurs when a MIDAS experiment changes from one run state to another. See [[Run States and Transitions]].  
 
: A transition occurs when a MIDAS experiment changes from one run state to another. See [[Run States and Transitions]].  
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'''U'''
 
'''U'''
 
;Utility
 
;Utility
: a MIDAS client application. '''Utility''' and '''Task''' are used in this document as alternatives to '''Application''' by different authors.
+
: a MIDAS client application. "Utility" and "task" are used in this document as alternatives to ''application'' by different authors.
  
 
------------  
 
------------  

Latest revision as of 16:26, 8 January 2016


Alphabetical Index

A
B
C
D
E
F
G
H
I J K L
M
N
O
P
Q
R
S
T
U
V
W
X Y Z

Glossary

A

Alias Button (Link)
User-created button on the Webserver Status Page providing a symbolic link to any desired ODB location or to an external webpage. Created by user via the /Alias ODB tree.
Application
MIDAS Applications are programs provided by the MIDAS system to perform various functions e.g. data logging, web server etc. They run as MIDAS #Clients.

B

Buffer
MIDAS maintains buffers (i.e. #Shared Memory) for ODB, System Messages, Data, Alarms and History system information. These buffers are managed by the Buffer Manager.

C

Client
A MIDAS Client is an #Application provided by the MIDAS system or (partially) written by the user (e.g. a #Frontend) that links with the MIDAS libraries and runs under the MIDAS system to allow the user to run a MIDAS #Experiment. MIDAS clients can be Local or Remote.
Local
A MIDAS client than runs on the Experiment Host.
Remote
A MIDAS client than runs on a Remote Host.
Custom
Button (Link)
User-created button on the Webserver Status Page providing access to a custom page. Custom links are created through the /Custom ODB tree.
Customscript Button

User-created button on a Webserver Custom Page which executes a script when pressed. Created by user via the /Customscript ODB tree.

Page
User-created Custom Page accessed from the Webserver Status Page. Created when the standard Webserver pages do not fully meet the user's requirements. It usually includes data from the ODB displayed according to the user's preference.

D

Data
Archiver
Application Lazylogger can copy the logged data files to another storage device.
Bank
data in an #Event with a bank header followed by data in a particular data format
Format
Data Formats "MIDAS" (a variable-length format) and "FIXED" are written by a #Frontend. The format used is determined by the #Equipment List. The data logger can convert MIDAS/FIXED formats to "ROOT" format.
Logger
Data Logger application mlogger serves multiple purposes related to data logging including logging experimental data to a storage device
Device
a Hardware module (e.g. a scaler) to be accessed by software called a device driver.
Driver
Also Device Driver. Software that allows access to a particular hardware module.

E

Environment Variables
Certain Environment Variables are used by MIDAS. Only MIDASSYS is required.
Equipment
see #Software Equipment
Hardware
Hardware Devices (e.g. a set of scalers) grouped together for convenience of data readout by a #Software Equipment.
Flag
Equipment Flags are used in the Equipment Type field in the EQUIPMENT structure of a frontend. The selected flag determines the Equipment Type.
List
declaration of a #Software Equipment in a Frontend using the EQUIPMENT structure defined in midas.h in the MIDAS package. When the frontend is started, the values in the equipment list for each defined Equipment will be written to the /Equipment ODB tree.
Software
usually called simply "equipment". A single or a collection of sub-tasks meant to collect and regroup logical or physical data (read from a hardware equipment) under a single and uniquely identified #Event. Each (Software) Equipment is defined using an equipment list in a #Frontend.
ReadOn Flags
ReadOn Flags are used in the "Read On" field of the equipment declaration to specify when the read-out of an event occurs.
Trigger
the event is triggered according to the equipment type.
Manual
A button is created automatically on the Webserver Status Page when an equipment with the equipment flag EQ_MANUAL_TRIGGER is present. A manually-triggered event is sent when button is pressed.
Type
Equipment Type determined by the equipment flag in the equipment list.
Event
a collection of data sent into the data stream by a Frontend Equipment, usually in the form of #Data Banks. The Event ID, Event Format, Event Buffer are determined by the #Equipment List for that event.
Format
see #Data Format
Buffer
Buffer to contain the events. The event buffer used (usually "SYSTEM") is determined by a parameter in the #Equipment List for that event.
Structure
Event consists of a header and a data area containing data banks. See Event Structure.
Experiment
a MIDAS experiment must be defined in order to run the MIDAS DAQ system. It is defined on the Experiment Host and is usually defined in the exptab file, which may define several MIDAS experiment.
Host
see #Host

F

Frontend
A MIDAS application built by the user which usually has access to hardware equipment in use by the experiment. Includes Frontend Code linked with a fixed framework mfe.c to form a Frontend. A slow-control frontend is used by the Slow Control System.
Code
The frontend code is the user-written part of the frontend application (e.g. frontend.c) describing sequence of actions to acquire the hardware data.
Equipment
See #Software Equipment

H

History
The MIDAS History System records useful information in parallel with the data logging. This can be displayed graphically.
Host
Computer running MIDAS clients, usually #Experiment Host.
Experiment
the experiment host is the host computer on which the MIDAS experiment #Shared Memory resides.
Remote
a remote host is a host computer on which (remote) MIDAS client(s) run which connect to the MIDAS experiment on the Experiment Host. See Quickstart Linux to set up a remote host.

M

MSCB
Slow Control Bus can be used for #Slow Control. Optionally can be built into MIDAS DAQ System.

O

ODB
The Online Data Base (ODB) contains all the information needed for an experiment. It can be accessed and/or edited using the ODB Page of the #Web Server or odbedit application.
Directory
The ODB is structured as a "directory". ODB directory is used as an alternative for ODB tree.
Key
Data in the ODB are contained in Key/Data pairs in an ODB tree or subtree. ODB Keys can be of various Types. In the Path /Logger/write data, the key is write data.
Type
ODB Key Types can be one of BYTE,CHAR,WORD,SHORT,DWORD,INT,BOOL,FLOAT,DOUBLE,STRING
Data
Data is contained in Key/Data pairs in the ODB. Use the #Web Server or odbedit application to view the Key/Data pairs.
Path
"address" used to access an ODB Key using the directory structure of the ODB, e.g. /Logger/write data. Upper/Lower Case is ignored.
Subdirectory
Alternative to ODB Subtree
Subtree
An ODB subtree starts at a lower level than an ODB Tree, e.g. /Experiment/Security subtree. May also be called a subdirectory.
Tree
data in the ODB are structured in a tree form with each "directory" dealing with a specific section of the acquisition. An ODB Tree starts at the root level "/", e.g. /Equipment ODB tree. May alternatively be called an ODB directory.

R

Remote host
see#Host
Run
A run starts when the MIDAS system receives a Start transition , and continues until it receives a Stop transition.
State
MIDAS defines three run states: Stopped, Paused and Running. See Run States and Transitions.

S

Script Button

User-created button on the Webserver Status Page which executes a script when pressed. Created by user via the /Script ODB tree.

Server
MIDAS
A remote procedure call (RPC) server mserver available for remote access to a MIDAS experiment.
Web
See #Web Server
Shared Memory
The MIDAS shared memory regions in RAM are called buffers, and managed by the MIDAS Buffer Manager. MIDAS uses shared memory for the ODB, System Messages, Data buffer, Alarms and History systems.
Saved Files
The MIDAS shared memory saved files (.*.SHM) for an experiment reside on the Experiment host at the path given by the Environment Variable MIDASSYS.
Slow Control system
Controls and monitors hardware that is not time-critical (e.g. high voltage modules, temperature sensors). See Slow Control System.
State
See #Run State

T

Task
a MIDAS client application. "Task" and "utility" are used in this document as alternatives to "application" by different authors.
Transition
A transition occurs when a MIDAS experiment changes from one run state to another. See Run States and Transitions.

U

Utility
a MIDAS client application. "Utility" and "task" are used in this document as alternatives to application by different authors.

W

Web Server
The MIDAS Web Server is the application mhttpd. It is accessible from a browser and is used to control and monitor a MIDAS experiment.