Model File Format

See also

The Xentara Model File in the Xentara user manual

JSON Format for OPC UA Server Instance

A JSON object describing an OPC UA server instance has the following syntax:

{
  "@Skill.OPCUAServer.Instance": {
    "name": "Server 1",
    "UUID": "58ed1445-1dc6-4c2f-84f2-8a0901183a4a",
    "ACL": { ... },
    "portNumber": 4840,
    "samplingMaxInterval": "24h",
    "samplingMinInterval": "50ms",
    "maxSecureChannels": 40,
    "maxSecurityTokenLifeTime": "10m",
    "maxSessions": 100,
    "maxSessionTimeout": "1h",
    "maxSubscriptions": 100,
    "applicationDescription": {
      ...
    },
    "roots": [
      "Lab.Plc",
      "Factory.Press Machine"
    ],
    "anonymousLogin": {
      "enabled": false
    },
    "allowUnencryptedConnections": {
      "enabled": false
    }
  }
}

Object Members

name	A string value containing the name of the instance. The name is used to construct the instance’s primary key.
UUID	A string value containing the unique UUID of the instance.
ACL	An optional JSON object containing the element ACL of the instance. The format of the object is described under JSON Format for ACLs in the Xentara user manual.
portNumber	An optional integer value containing the TCP port number of the server. The default value is 4840.
samplingMaxInterval	A optional string value containing the maximum sampling interval allowed by the server. The default value is 24 hours. The format of the string is described under JSON Format for Time Intervals.
samplingMinInterval	A optional string value containing the minimum sampling interval allowed by the server. The default value is 50 milliseconds. The format of the string is described under JSON Format for Time Intervals.
maxSecureChannels	An optional integer value containing the maximum number of secure channels allowed by the server. The default value is 40.
maxSecurityTokenLifeTime	A optional string value containing the maximum secure channel security token lifetime allowed by the server. The default value is 10 milliseconds. The format of the string is described under JSON Format for Time Intervals.
maxSessions	An optional integer value containing the maximum number of sessions allowed by the server. The default value is 100.
maxSessionTimeout	A optional string value containing the maximum session timeout value allowed by the server. The default value is 1 hour. The format of the string is described under JSON Format for Time Intervals.
maxSubscriptions	An optional integer value containing the maximum number of subscriptions allowed by the server. The default value is 100.
applicationDescription	An optional JSON object containing the server application description. By default the configuration described in application description is used.
roots	An optional JSON array containing a list of Xentara elements that must be used as the address space roots of the OPC UA server instance. Subtrees of the Xentara model tree starting from the configured roots will be added to the address space all the way down to a data point or a skill data point. When "roots" are not configured, the elements immediately below the Xentara model tree root will be considered as the address space roots.
anonymousLogin	An optional JSON object containing the server configuration for logging in using the anonymous identity token. By default the anonymous login is disabled. The object has only one member called "enabled" of type boolean that activates or deactivates the anonymous login possibility. Warning Enabling anonymous login can expose your system to security risks. Unless absolutely necessary, avoid enabling anonymous login. Use certificate or user name and password authentication mechanisms instead.
allowUnencryptedConnections	An optional JSON object containing the server configuration for switching the security policy none endpoint on and off. By default the security policy none is disabled. The object has only one member called "enabled" of type boolean that activates or deactivates the security policy none endpoint hence, allowance of unencrypted connections to the server. Warning Unencrypted connections pose serious security risks. It is strongly recommended to use encrypted connections to protect sensitive data. Avoid transmitting information over unsecured channels.

JSON Format for Application Description

JSON object for application description contains values describing the OPC UA server instance according to OPC foundation reference. The object has the following format:

"applicationDescription": {
      "applicationUri": "",
      "productUri": "",
      "applicationName": "OPC UA Server",
      "gatewayServerUri": "",
      "discoveryProfileUri": "",
      "discoveryUrl": "opc.tcp://discoveryUrl.opcua.local:4840"
}

Object Members

applicationUri	An optional string value containing the application URI. The default value is automatically generated based on the host machine configuration.
productUri	An optional string value containing the product URI. The default value is https://www.xentara.io.
applicationName	An optional string value containing the application name. The default value is the server instance primary key.
gatewayServerUri	An optional string value containing the gateway server URI. By default the gateway server URI is set as unspecified.
discoveryProfileUri	An optional string value containing the discovery profile URI. By default the discovery profile URI is set as unspecified.
discoveryUrl	An optional string value containing the discovery URL. The discovery URL value must start with opc.tcp:// prefix. The default value is automatically generated based on the host machine configuration and the port number of the server instance.