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= Data Source =

'''OPC Server''': National Instruments.Variable Engine.1[[BR]]
'''Data Path''': /ZeusLibrary[[BR]]
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= Provided Variables =
 * '''__!ZeusOperation__''' - Provides textual information about current Zeus operation
 * '''__!ZeusLiveMessage__''' - This integer variable is continuously updated by Zeus in order to indicate it is alive and running
 * '''__!ZeusError__''' - If Zeus operation is stopped because of the error this variable contains textual description of the error. Otherwise (if Zeus running in normal state) it contains empty string.
 * '''__!ZeusLogGroups__''' - Provides information about all !LogGroups configured within Zeus. Please, find format description [#FormatofZeusLogGroupsVariable below].
 * '''__!ZeusDisable__''' - A boolean variable indicating if the data logging is enabled (false) or disabled (true).
 * '''__!ZeusCommand__''' - This variable is used to control Zeus operation and change a run-time configuration. The supported commands are listed [#SupportedCommands below].
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= Format of !ZeusLogGroups Variable =
To provide !LogGroups information the ''!ZeusLogGroups'' text variable is exported by Zeus OPC Interface. The variable contains descriptions of all configured !LogGroups separated (and terminated) by ';' sign:
{{{
<LogGroup1>;<LogGroup2>;<LogGroup3>;
}}}
For each !LogGroup the ''Database ID'', ''Name'', ''Update Interval'' (in seconds) and ''On/Off Status'' are specified. The following format is used:
{{{
  <ID>,<LogGroup Name>,<Update Interval>,<Status>
}}}

The fields are separated by comas. To indicate ''On State'' the value of ''1'' should be specified in the Status field and ''0'' is used for ''Off State''. The following example describes two !LogGroups: ''First Group'' and ''Second Group''. Both are switched on. The first one is updated once a second and second one - once a minute.
{{{
1,First Group,1,1;2,Second Group,60,1;
}}}
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= Supported Commands =
 '''START'''::
  Enables data logging
 '''STOP'''::
  Disables data logging
 '''LGSTATE''' ''GrID'' ''Mode''::
  Changes On/Off Status of the specified !LogGroup.
 * ''GrID'' - Database ID of considered !LogGroup (available from [#FormatofZeusLogGroupsVariable ''ZeusLogGroups'' variable])
 * ''Mode'' - New Status
  * 0 - Off, No Logging
  * 1 - On, Logging on the basis of the configured interval
  * 2 - On, Logging on the basis of the configured deadband
  * 3 - On, Logging on the basis of the configured interval & deadband
 '''LGRATE''' ''GrID'' ''Rate''::
  Configures update interval of the specified !LogGroup
 * ''GrID'' - Database ID of considered !LogGroup (available from [#FormatofZeusLogGroupsVariable ''ZeusLogGroups'' variable])
 * ''Rate'' - Double value specifying new logging rate in seconds