Configuration of the alarm history

The "General" and "Advanced" tabs enable the following settings for the alarm history:

General" tab

Logged alarm statuses

Defines which alarm statuses are to be logged. You can find more information on this in the Alarm statuses chapter.

File path

Specifies the path for all historical alarm or log files. The path specification can be both absolute (the button opens a dialogue for selecting a directory) and relative to the project directory (the keyword <ProjectDir> initiates the relative path specification, e.g: <ProjectDir>\Alarme) can be specified.

File name

Specifies a file name. The file name is set either automatically or manually:

• Automatic

  The file name is formed from the current date (possibly also the current time) at which the file was created.

• Manual

  Similar to a language-related text in the index text editor, the file name can contain a dynamically integrated process variable value. The button opens a dialogue for including a dynamic process variable value.

File change event

The file change event is used to determine when a new file is created. The following settings are possible here:

• Daily

  A new alarm history file is created for the date change.

• Weekly

  A new file is created at the end of the week.

• Monthly

  A new file is created at the end of the month.

• Annually

  A new file is created at the turn of the year.

• Trigger

  A new file is created when the trigger variable is set.

• Never

  The system does not carry out a file change independently. However, it is possible to trigger a file change from the programme code using the functions in the "VisiWin.Alarm" or "VisiWin.Logging" namespace.

• Time span

  A new file is created cyclically after a period of time has elapsed. The time period is defined via the fields Day, Hour, Min.

Trigger variable

Specifies the name of a binary variable that serves as a trigger for the file change. The field is only active if the "Trigger" setting has been made in the "File change event".

File mode

Describes whether the file should be saved quickly or securely:

• Fast

  The historical alarm or log file is kept open until the swap event. This increases the performance of file access. However, in the event of a crash, there is no guarantee that the content of the file is correct.

• Safe

  If this option is activated, the historical alarm or log file is closed again by the alarm or log server after each write access. This increases security in the event of a system crash, but can slow down the system under certain circumstances.

Bypass Windows write cache

If this option is activated, the data is written directly to the hard drive without being buffered in the Windows write cache (deactivated by default).

Max. Total file size

Specifies the maximum storage space that the historical alarm files or log files may occupy on the hard drive. If the size specified here (in kilobytes) is exceeded, the oldest files are deleted. This serves to protect the hard disk from overflowing. If the File mode parameter is set to "Fast", the size specified here may be exceeded. The size comparison is only carried out after the data held in the internal buffer has been written to the file. If the amount of data buffered internally is very large, this may result in several older files having to be deleted in order to comply with the maximum total file size. Specifying the value 0 (default setting) means that no limit is executed.

Max. Number of files

Defines the maximum number of historical alarm files or log files that can be created on the hard drive. If the number specified here is exceeded, the oldest files are deleted. This serves to protect the hard drive from overflowing. Specifying the value 0 (default) means that no limit is executed.

File format" tab

file format

Defines the format in which the historical databases are saved. You can choose between Microsoft Access 2000 databases and MS SQL Server databases.

SQL server name

If SQL Server is selected in the file format, the computer name of the computer on which the SQL Server was installed and on which the historical alarm databases are created can be specified here.

Security

The selection of the settings available here depends on the authorisations in the database.

• Using the integrated security of Windows NT

  Uses the role of the logged-in user in the network to authenticate themselves.

• Use a specific user name and password

  The user name and password must be administered in the database.

User name

Name of the user to authenticate with the database.

password

Password of the user to authenticate to the database.

Connection TimeOut

Specifies the time-out for the connection to the SQL server in milliseconds. The field is only active if SQL server has been selected in the File format parameter. The time-out specified by the SQL server is usually quite high (e.g. 60 seconds), which delays the start time of the visualisation and leads to the incorrect assumption that the visualisation has crashed. This parameter can be used to reduce the time-out for establishing a connection to the SQL server to a few seconds.

Include the computer name of the VisiWin server in the database name

If this option is activated, the computer name is inserted before the names of the databases created by the SQL server. This option is useful if a central SQL server saves the files of several »EASY UI Designer« applications running in the network. The source of the recording can then be read from the computer name in the database name.