Server System Tags

The Movicon.NExT Data Server defines a list of tags which are available for entire project use on both client and server. However, there are Tags that are only available for use on the Client side. These tags are very handy to use in certain situations when the Data Server is not used.

The Tags that can be used only when selected on the Client side are:

System Tags
Local Tags

Both types are described in the chapter on Client Visualization.

System Tags

The Server's System Tags relating to the project are exposed in the "SystemTags" folder as shown in the screen shot below:

The below table list all the exposed variables with their descriptions:

Group	Tag Name	Data Type	Description
Alarms	SoundState	Boolean	Tag for reading or setting the alarm sound state to activated or deactivated.
	NumActiveOff	Int64	Number of alarm active with OFF status.
	NumActiveOn	Int64	Number of alarm active with ON status.
	NumActiveOnOff	Int64	Number of alarm active with ON and OFF status.
	NumEnabled	Int64	Number of enabled alarms.
	NumNotAck	Int64	Number of acknowledged alarms.
	NumShelved	Int64	Number of shelved alarms.
Eventlogger	DeleteEntriesPending	Integer	Number of pending delete entries to be performed.
	DeleteEntriesRunning	Integer	Number of Delete entries being run.
	DischargingEntries	Boolean	“True” when discharging data entries due to reaching internal memory cache limit (Max Pending Entries).
	FailsEntriesPending	Integer	Number of failed entries pending database recording.
	FailsEntriesRunning	Integer	Number of previously failed entries being recorded on database.
	FlushEntriesPending	Integer	Number of entries pending flush to local XML file after the maximum number of attempts failed to record on Database.
	FlushEntriesRunning	Integer	Number of entries being flushed to the local XML file to then be retrieved by the system when database re-entered from error state.
	RecordEntriesPending	Integer	Number of entries pending database recording.
	RecordEntriesRunning	Integer	Number of entries being recorded on database.
Historian	DeleteEntriesPending	Integer	Number of delete operations pending execution.
	DeleteEntriesRunning	Integer	Number of delete operations being run.
	DischargingEntries	Boolean	“True” when discarding data entries due to reaching the internal memory cache limit (Max Pending Entries).
	FailsEntriesPending	Integer	Number of entries waiting to be recorded on database and which failed the previous attempt to do so.
	FailsEntriesRunning	Integer	Number of entries being recorded on database and which failed the precious attempt to do so.
	FlushEntriesPending	Integer	Number of entries waiting to be flushed to the local XML file due to exceeding the maximum number of attempts after the last attempt to be recorded on database failed.
	FlushEntriesRunning	Integer	Number of entries being flushed to the local XML file to then be retrieved by the system when database returns back from error state.
	RecordEntriesPending	Integer	Number of entries waiting to be recorded on database.
	RecordEntriesRunning	Integer	Number entries being recorded on database.
System	DynamicTags	Integer	Returns the number of TAGs counted for license purposes. Each 'simple' tag from 1 to 64 bit is counted as a licensed TAG while each member of an array or structure tag counts as 1 TAG.
Redundancy	RedundancyActiveServerState	Boolean	Indicates whether the local server is active or inactive. Each server indicates its on status.
	RedundancyActiveServerHostName	String	This tag is redundant in all the Servers that have been started up and reports the name of the Active Server which is the one in control.
	RedundancyArrayAliveServerHostName	String	This tag is redundant in all Alive Servers and reports the list of names of those Servers which are currently alive.
	RedundancySwitchActiveServer	Method	This method, which can be executed both in the Active Server and inactive Server, switches the Active Server when invoked. This method is enabled when there are two Servers on the list only and if the 'Keep Server Active' redundancy property has been enabled.
	RedundancyActiveServerHostName	String	Active redundant server hostname.
	RedundancyArrayAliveServerHostName	String	List of available redundant server hostnames.
	RedundancySwitchActiveServer	Method	Method that allows you to change the active redundant server.

OPC-UA Server Tags

Server Syster Tags exposed according to the OPC UA specifications can be found in the "Server" folder as indicated below:

The below table lists the exposed variables with their descriptions:

Group	Variable Name	Data Type	Description
Server	ServerArray	String	Defines an URI server Array. This variable is also defined Server table. Each URI in this array represents an unique global logic name for a Server in the network environment in which it is installed. Each OPC Server instance has an individual URI used in the table of servers of other OPC UA Servers. The 0 index is reserved for the URI of local ServerOFs. Values greater than 0 are used to identify remote servers and are specific to a particular server.
	NamespaceArray	String	Defines an Array of the URI "NameSpace". This variable is also defined as "NameSpace" Table. The indexes in this table are called NamespaceIndexes. The "NameSpaces" are used in NodeIds of OPC UA services, instead of in the URI of the space of longer names. The 0 index is reserved for the OPC UA "NameSpace", The index 1 is reserved for the local server. Clients can read the whole table or individual items in the table. The server must not modify or remove any of the items from this table while clients have a session opened in the server, since they memorize this table in their cache. However, a server can add items to the table even when clients are connected to the server. Therefore it is advised that servers do not modify the table's indexes but only add items, because clients can memorize the NodeIds in the cache using the indexes. The Clients that memorize the NamespaceIndexes of NodeIdsI in the cache should always check that the NamespaceIndexes are not already present in the cache when starting up a session.
	ServerStatus	String	This contains elements that describe the state of the server.
	ServiceLevel	Byte	Provides information to a Client concerning the operation state of a Serca and its capacity to provide data. The ServiceLevel is one byte with a range between 0 and 255, within which the values reenter into secondary ranges as follows (only in Windows operating systems): 0 or 1: the server is in mantenance state or in error. A client is unableto exchange any information with it. From 100 to 155: the communication driver is in error. The subrange allows a server to provide information that can be used by clients to balance the load of the server's CPU. From 200 to 255: Server is fully operative. Therefore, Clients can obtain information from this Server. This subrange allows a serve to provide information that can be used by clients to balance the load. One example of using this ServiceLevel subrange would be to reflect the server's CPU load. The tag's value in Linux operating systems does not change according to the use value of the CPU and can be: 0 or 1: the server is in maintenance state or in error. Client is unable to exchange information with it. 155: the communication driver is in error. 255: the Server is fully operative. Therefore, Clients can obtain all information from this Server.
	Auditing	Boolean	This is a boolean value that specifies whether the server is currently generating Audit events. It is set to TRUE if the server generates control events otherwise it will be set to FALSE.
	EstimatedReturnTime	DateTime	Indicates the estimated time with which the server will return back to being available on the list of active servers.

Server Capabilities	ServerProfileArray	String	Defines the server's conformity profile.
	LocaleldArray	LocaleId	This is a Local Array supported by the Server. The server may not be aware of all the supported LocaleId if systems or underlying devices, that have been granted access, do not report the LocaleId supported.
	MinsupportedSampleRate	Duration	This defines the minimum sample rate, including 0, that is supported by the server.
	MaxBrowseContinuationPoints	Duration	This is an integer that specifies the maximum number of "Continuation Points", parallel with the Browser service, that the server can support per session. The value specifies the maximum continuation points that the server can support under normal circumstances, therefore there is no guarantee that the server will be able to support this maximum. The client must not open multiple Browse calls with more "Continuation Points" open in respect to those exposed by this variable. The 0 value indicated that the server does not place any limit on the number "Continuation Points" in parallel to those that can be used by the client.
	MaxQueryContinuationPoints	UInt16	This is an Integer that specifies the maximum number of "Continuation Points" in parallel with QueryFirst services that the server can support per session. The value specifies the maximum continuation points that the server can support under normal circumstances, therefore there is no guarantee that the server will be able to support this maximum. The client must not open multiple QueryFirst calls with more "Continuation Points" open in respect to those exposed by this variable. The 0 value indicated that the server does not place any limit on the number "Continuation Points" in parallel to those that can be used by the client.
	MaxHistoryContinuationPoints	UInt16	This is an Integer that specifies the maximum number of "Continuation Points" in parallel with ReadHistory services that the server can support per session. The value specifies the maximum continuation points that the server can support under normal circumstances, therefore there is no guarantee that the server will be able to support this maximum. The client must not open multiple ReadHistory calls with more "Continuation Points" open in respect to those exposed by this variable. The 0 value indicated that the server does not place any limit on the number "Continuation Points" in parallel to those that should used by the client.
	SoftwareCertificates	SignedSoftwareCertificates	This is a software certificates Array containing all the certificates supported by the server. this must be ths same list certificated returned by the "CreateSession" service. The certificates in this property are not signed.
	MaxArrayLength	UInt32	The maximum Array value length supported by the server.
	MaxStringLength	UInt32	The maximum string value length supported by the server.
	MaxByteStringLength	UInt32	The maximum Byte string value length supported by the server.

Server Configuration	ServerCapabilities	String	Defines the capabilities supported by the OPC UA server.
	SupportedPrivateKeyFormats	String	This specifies the PrivateKey formats supported by the server. The possible values include "PEM" (see RFC 5958) or "PFX" (see PKCS # 12). The array is empty if the server does not consent external clients to update the PrivateKey.
	MaxTrustListSize	Uint32	This is the maximum size of the Trust LIst in bytes. 0 signifies no limit. The predefined setting is 65 535 bytes.
	MulticastDnsEnabled	Boolean	When TRUE, the server will be announced using a DNS multicast (this can be modified by writing in the variable).

Server Diagnostics	ServerDiagnosticsSummary	ServerDiagnosticsSummaryDataType	Contains Diagnostics summary for the server.
	SubscriptionDiagnosticsArray	ServerDiagnosticsSummaryDataType	This is a diagnostics subscription information Array. There is an item for each notification channel effectively established in the server. Its TypeDefinitionNode is the VariableType SubscriptionDiagnosticsArrayType, which provides a variable for each array item. These variables are also used as variables to which other variables can refer to.
	EnabledFlag	Boolean	This identifies whether or not the server collects the diagnostics information. It can also be used by clients to enable or disable the server's diagnostics information collection. The following boolean value settings are applied: TRUE indicates that the server collects diagnostics information and when value is set to TRUE, the collection of diagnostics information is restored and enabled. FALSE indicates that no statistical information has been collected and setting the value to FALSE disables the collection without restoring the statistics values.

Server Redundancy	RedundancySupport	RedundancySupport	This indicates which redundancy is supported by the server.
	CurrentServerid	String	This is a value that is needed to identify the currently used server in the redundancy set.
	RedundantServerArray	RedundantServerArrayDataType	This is a value that contains an array of servers available in the redundancy set.
	ServerUriArray	String	This is an array with the URIs of all the OPC UA Server-s redundant servers. As this is a nontransparent redundancy ambient, the client responsible for the subscription to redundant servers, may or may not be able to open a session with one or more redundant servers of this array.
	ServerNetworkGroups	NetworkGroupDataType	This contains an Array of NetworkGroupDataTypes. The URIs of servers of this array (in the structure's serverURIs) must be exactly the same as those provided in the ServerUri Array despite in a different order. Therefore, the array should represent a list of HotAndMirrored redundant servers. If one server only supports the network redundancy, it will have only one item in the ServerNetworkGroups. The NetworkPaths in the structure present the redundant network paths for each server. The NetworkPaths describe the different paths (one item for each path) ordered by priority: Each network path contains an endpointUrlList with a string matrix, each one containing an endpoint URL. This will allow different protocol options to be used for the same network path.