Systems.xml File Attributes
When you use the Client Configuration applet to configure a client - system connection, the settings you define are saved within the auto-generated Systems.xml file as attributes and values. If you create or edit a Systems.xml file manually, you can include the attributes in your file and also define their values.
Many of the elements in a Systems.xml file have attributes for which you can set values. The attributes correspond to the settings on the Client Configuration applet and the various displays that you can access via the Client Configuration applet, such as the Advanced Settings window.
For each of the elements, you need to define or edit the attributes correctly:
XML is case-sensitive. To be valid in XML files, Boolean 'true' and 'false' values must be fully lower case.
The <Systems> element has no attributes.
Defines the name of the default system. If a system is not defined in the <System> attributes, the client will connect to the system specified as the Default System instead. The <Default System> corresponds to the Set as Default setting on the Geo SCADA Expert Client Applet.
For the <Default System> element, you need to define the name of the default system in the following format:
<Default System="name of system" />
Where name of system is the name of the default system, for example, <Default System="Main" /> sets the default system to the system named Main.
Has attributes that correspond to the settings on the Geo SCADA Expert Client Configuration window:
The name of the system. This required string value corresponds to the System Name setting on the Client Configuration window (see Define the System Name and Type for a Client - System Connection).
The type of system to which the client will connect. This required string value matches the Type setting on the Geo SCADA Expert Client Configuration window. You can specify any of the following (enter the text on the left to specify the required connection type):
- SCX—To connect to a Geo SCADA Expert server
- OPCDA—To connect to an OPC Data server
The OPCAE and OPCHDA options that were available in previous releases of Geo SCADA Expert and ClearSCADA are no longer supported.
For more information, see Define the System Name and Type for a Client - System Connection.
Defines whether the system is online (enabled) or offline (disabled). This optional Boolean value corresponds to the Disable setting on the Geo SCADA Expert Client Applet.
Defines whether the client connection can be detected by ViewX. In some circumstances, you may want the client connection to only be available to third-party OPC clients and not ViewX clients. This optional Boolean value corresponds to the Visible in ViewX setting on the Client Configuration window (see Define Whether the System is Visible in ViewX).
Defines whether the client uses client licensing. This optional Boolean value corresponds to the Use Client Licensing setting on the Geo SCADA Expert Client Configuration window. When it is true, client licensing is enabled; when it is false, client licensing is disabled. For more information, (see Enable or Disable Client Licensing).
This attribute is now obsolete. Do not use this attribute in new Systems.xml files. The attribute is supported for backward compatibility.
Defines whether the client connects to fully synchronized servers only. This optional Boolean value corresponds to the Connect to Fully Synchronized Server setting on the Client Configuration window (see Connect Client to Fully Synchronized Server Only).
If this attribute is omitted from the Systems.xml file, its default setting (false) is used.
Defines whether the client is required to validate the server's certificate when a communications link is being established. This optional Boolean value corresponds to the Validate Server Certificate setting on the Connection Security window that is available from the Client Configuration window (see Configure the Client Connection Security Settings).
If this attribute is omitted from the Systems.xml file, its default setting (false) is used.
Defines the method by which a client certificate is selected when a communications link is being established. This optional attribute corresponds to the Client Certificate Mode and Client Certificate Selection settings on the Connection Security window that is available from the Client Configuration window (see Configure the Client Connection Security Settings). The possible options are:
- 0—Disabled. No certificate will be supplied to the server.
- 1—Automatic. If the server requests a certificate then one will be selected automatically, based on the CA root certificates that the server trusts.
- 2—Specified. If the server requests a certificate then one specified via the selectClientCertByHash or selectClientCertBySubjectSubstring attribute will be selected. If both attributes are present in the Systems.xml file then selectClientCertByHash will take precedence.
If this attribute is omitted from the Systems.xml file, its default setting (1) is used.
Optionally include either this attribute or the selectClientCertBySubjectSubstring attribute when the clientCertMode attribute is set to 2 (see above). The value of this attribute is a string. The string specifies the full hash string of the certificate that should be selected when establishing a communications link.
The value of this attribute is ignored if the clientCertMode attribute is set to a value other than 2, or is not included in the Systems.xml file.
Optionally include either this attribute or the selectClientCertByHash attribute when the clientCertMode attribute is set to 2 (see above). The value of this attribute is a string. The string specifies a portion of the subject name of the certificate that should be selected when establishing a communications link. If more than one certificate has a subject name that contains the string, a certificate will be selected based on the CA root certificates that the server trusts.
The value of this attribute is ignored if the clientCertMode attribute is set to a value other than 2, or is not included in the Systems.xml file.
The workstation name of the client. This optional string value corresponds to the Workstation Name setting on the Client Configuration window (see Define the Workstation Name for the ViewX Client).
Defines an order of preference for the client - server connection. This value of this optional attribute corresponds to the Default System Priority setting on the Client Configuration window
Has attributes that correspond to the Node tab settings on the Geo SCADA Expert Client Configuration window and the settings on the Advanced Settings window:
This optional string allows you to define the name of the server node. This attribute corresponds to the Node Name setting (see Define the Node Name for a Client - System Connection).
This optional integer allows you to define the node cost (which is used by Geo SCADA Expert to determine the order of preference for the client’s connections). This attribute corresponds to the Node Cost setting (see Define the Node Cost for a Client - System Connection).
This optional integer allows you to define the number of the port that the client uses for outgoing communications to the system server. This attribute corresponds to the Port setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection)
This optional Boolean allows you to define whether data compression is enabled (true) or disabled (false) for the client - system connection. This attribute corresponds to the Compress setting (see Define the Client Compression Settings for a ViewX Client Connection).
This optional integer allows you to define the amount of time, in milliseconds, in which the client can attempt to make a connection to the server. This attribute corresponds to the Connect Timeout setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection).
This optional integer allows you to define the amount of time, in milliseconds, in which the client can request data from the server. This attribute corresponds to the Request Timeout setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection).
This optional integer allows you to define the amount of time, in milliseconds, in which the client can attempt to terminate a connection to the server. This attribute corresponds to the Disconnect Timeout setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection).
This optional integer allows you to define the amount of time, in seconds, that can elapse between each update request sent from the client to the server. This attribute corresponds to the Poll Interval setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection).
This optional integer allows you to define the amount of time, in seconds, that the client will wait for a response to a poll request from the server. This attribute corresponds to the Poll Timeout setting (see Define the Port and Poll Timeouts and Intervals for a ViewX Client Connection).
When you use the Geo SCADA Expert Client Configuration Tool to configure a connection, the resulting Systems.xml file contains auto-generated <opcdaclsid>, <opchdaclsid>, and <opcaeclsid> elements. These elements can allow third-party OPC clients to connect to a system and can only be included as part of a Geo SCADA Expert generated Systems.xml file. You cannot include them in manually edited Systems.xml files - you should use the Geo SCADA Expert Client Configuration Tool to configure third-party OPC Client connections (see Third-Party OPC Client - System Connections).
Example: Systems.xml file for a ViewX client with Connections to 2 Servers
The following example shows the contents of a valid Systems.xml file for a ViewX client that is connected to a single logical database called "Main". The logical database "MAIN" is implemented on two servers called "TAPC04" and "TAPC06" respectively:
<Systems>
<Default system="MAIN"/>
<System name="MAIN" type="SCX" enabled="true" visibleInViewX="true"
<Server name="TAPC04" cost="6" port="5481" compress="false" connectTimeout="30000" requestTimeout="120000" disconnectTimeout="30000" pollInterval="10" pollTimeout="15000">
</Server>
<Server name="TAPC06" cost="8" port="5481" compress="false" connectTimeout="30000" requestTimeout="120000" disconnectTimeout="30000" pollInterval="10" pollTimeout="15000">
</Server>
</System>
</Systems>